Researcher basic information

• Ph.D, The University of Tokyo, Mar. 1999

• https://researchmap.jp/masatomo-fujiwara?lang=en

• https://orcid.org/0000-0001-5567-4692
• https://jglobal.jst.go.jp/detail?JGLOBAL_ID=200901092392643540
• http://wwwoa.ees.hokudai.ac.jp/~fuji/index_jp.html
• http://wwwoa.ees.hokudai.ac.jp/~fuji/index.html

• 00360941

• https://orcid.org/0000-0001-5567-4692

• F-7852-2012

• 200901092392643540

• Atmospheric Science
• Meteorology

• Natural Science, Atmospheric and hydrospheric sciences

• Master's degree program, Graduate School of Environmental Science
• Doctoral (PhD) degree program, Graduate School of Environmental Science

Research activity information

• Feb. 2025, American Meteorological Society, Scientific and Technological Activities Commission (STAC) Technological Accomplishment Award 2025
  "For exceptional leadership of the SPARC Reanalysis Intercomparison Project and unremitting dedication to developing and evaluating middle atmosphere measurements"
  Masatomo Fujiwara
• Feb. 2024, Meteorological Society of Japan, The SOLA Award in 2023
  Suzuki et al., Development of a new particle imaging radiosonde with particle fall velocity measurements in clouds, Scientific Online Letters on the Atmosphere, 19, 261−268, 2023
  Suzuki, K;Y. Hara;T. Sugidachi;K. Shimizu;M. Fujiwara, Official journal
• 2018, Sustainability Science, 2017 Sustainability Science Best Paper Awards - Outstanding Article (Sugiyama et al., SS, 2017)
  Sugiyama et al., Official journal
• 2010, Meteorological Society of Japan, 2010 JMSJ Award
  for papers by Sakazaki and Fujiwara (JMSJ, 2010a, 2010b)
  Takatoshi Sakazaki;Masatomo Fujiwara
• 2000, Meteorological Society of Japan, Yamamoto-Shono Medal, Meteorological Society of Japan, 2000
  for paper by Fujiwara et al. (JGR, 1998)
  Masatomo Fujiwara

• Ozone formation sensitivity based on the secondary formaldehyde-to-nitrogen dioxide ratio (FNR _sec ) derived from ground-based remote sensing measurements and a chemical transport model
  Nguyen Doan Thien Chi; Hiroshi Tanimoto; Satoshi Inomata; Kohei Ikeda; Yange Deng; Royston Uning; Tamaki Fujinawa; Astrid Müller; Masatomo Fujiwara; Shungo Kato; Hisahiro Takashima
  Atmospheric Chemistry and Physics, 26, 11, 8275, 8294, Copernicus GmbH, 12 Jun. 2026, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal, Abstract. Sensitivity analysis is essential for developing effective ozone (O3) mitigation strategies. This study aims to extensively investigate the diurnal, seasonal, and vertical chemical sensitivity of O3 using a photochemical indicator, the secondary formaldehyde (HCHO)-to-nitrogen dioxide (NO2) ratio (FNRsec) as measured by Pandora remote-sensing spectrometers located across Japan. Region-specific FNRsec thresholds were determined using the GEOS-Chem chemical transport model. Surface concentrations and vertical column amounts of HCHO and NO2 were obtained from in situ measurements and Pandora spectrometers. The concentrations of HCHO and NO2 varied with season and altitude. Moreover, external pollution transport affected the vertical profiles and likely contributed to elevated concentrations. During exceedance events, the O3 sensitivity analysis showed that NOx-limited conditions were dominant in summer, transitional regimes in spring and fall. Vertically, ROx-limited conditions typically formed near the surface layers, followed by transitional regimes in the mid-levels, and NOx-limited regimes aloft. Therefore, O3 mitigation strategies should target not only the surface level but also elevated altitudes. This study contributes to fostering a comprehensive understanding of O3 sensitivity in the troposphere using FNRsec retrieved from Pandora measurements.
• Stratosphere‐Troposphere Exchange of Ozone and CO Over the North Pacific: Roles of Different Types of Rossby Wave Breaking With Multiple Chemical‐Reanalysis Perspectives
  Haosen Xi; Masatomo Fujiwara
  Journal of Geophysical Research: Atmospheres, 131, 28 Mar. 2026, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• The Asian Summer Monsoon Chemical and Climate Impact Project (ACCLIP): An Overview
  L. L. Pan; E. L. Atlas; P. A. Newman; T. Thornberry; K. W. Jucks; O. B. Toon; W. J. Randel; Q. Liang; D. E. Kinnison; R. Ueyama; J. F. Bresch; S. B. Honomichl; W. P. Smith; R. S. Hornbrook; L. Ziemba; M. Fujiwara; E. C. Apel; M. Barucci; G. Bianchini; M. Brown; T. P. Bui; T. Campos; M. Chin; F. D’Amato; J. Dean‐Day; G. Diskin; A. Franchin; C. Gurganus; L. T. Iraci; J. Kim; J.‐H. Koo; L. R. Lait; K. Lesko; J. R. Podolske; A. Rollins; T. Sakai; K. Shiraishi; V. Treadaway; S. Viciani; E. Waxman
  Journal of Geophysical Research: Atmospheres, 130, 23, American Geophysical Union (AGU), 28 Nov. 2025, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal, Abstract
  
  The Asian summer monsoon Chemical and Climate Impact Project is centered on a large airborne field campaign investigating the role the Asian Summer Monsoon (ASM) plays in changing the atmospheric composition in the upper troposphere and lower stratosphere. This campaign, conducted in Summer 2022 using two research aircraft, has obtained the most comprehensive data set for chemical composition, including hundreds of trace gas species as well as the physical and chemical properties of aerosols in the ASM convective outflow over East Asia and the Western Pacific. These data show that the ASM deep convection is creating a chemically distinct layer near the tropopause that has large anthropogenic influences. This overview provides a summary of the project, including the scientific objectives, dynamical, and meteorological conditions of the campaign season, key elements of the campaign operations, selected scientific highlights, and ongoing research.
• Characterization of Pandora Sky-Scan Modes from the Japan Pandora Network and Evaluation of Their Use in Validating Satellite NO ₂ and HCHO Retrievals
  Nguyen Doan Thien Chi; Hiroshi Tanimoto; Satoshi Inomata; Tamaki Fujinawa; Astrid Müller; Takafumi Sugita; Shungo Kato; Nobuhiko Kuze; Yugo Kanaya; Masatomo Fujiwara; Jun Hirokawa; Hisahiro Takashima; Tomoo Nagahama; Kazuyo Yamaji; Soichi Hirokawa; Sang-Woo Kim; Prajjwal Rawat; James H. Crawford
  ACS ES&T Air, 2, 2872, 2888, American Chemical Society (ACS), 25 Nov. 2025, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• The AquaVIT-4 intercomparison of atmospheric hygrometers
  Simone Brunamonti; Harald Saathoff; Albert Hertzog; Glenn Diskin; Masatomo Fujiwara; Karen Rosenlof; Ottmar Möhler; Béla Tuzson; Lukas Emmenegger; Nadir Amarouche; Georges Durry; Fabien Frérot; Jean-Christophe Samake; Claire Cenac; Julio Lopez; Paul Monnier; Mélanie Ghysels
  Atmospheric Measurement Techniques, 18, 5321, 5348, 15 Oct. 2025, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal
• Tropical volcanic impacts on MENA climate via ENSO and NAO dynamics in a high-top model
  Muhammad Mubashar Dogar; Shingo Watanabe; Masatomo Fujiwara; Muhammad Adnan Abid; Turki M. Habeebullah; Basit Khan
  npj Climate and Atmospheric Science, 8, 1, Springer Science and Business Media LLC, 29 Sep. 2025, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal, Abstract
  
  Volcanic eruptions are among the strongest climate drivers, yet their regional impacts on the Middle East and North Africa (MENA) remain poorly constrained. Post-eruption amplified winter cooling in MENA is often attributed to a volcanically forced positive North Atlantic Oscillation (NAO), but the concurrent occurrence of El Niño–Southern Oscillation (ENSO) complicates attribution. Furthermore, summer climatic responses, including tropical warming and mid-latitude cooling, remain underexplored. Here, we present a pioneering research using a high-top coupled climate model (MIROC6) to assess volcanic-induced ENSO–NAO interactions and their regional climate impacts. We demonstrate that volcanic-induced NAO variability is the primary driver of post-eruption MENA winter cooling, with El Niño acting as a modulator rather than a fundamental trigger. We further reveal distinct summer climate anomalies, including suppressed precipitation over the Intertropical Convergence Zone (ITCZ). These findings underscore the importance of high-top models to resolve stratospheric influences on post-volcanic climate variability.
• Observational ozone datasets over the global oceans and polar regions (version 2024)
  Yugo Kanaya; Roberto Sommariva; Alfonso Saiz-Lopez; Andrea Mazzeo; Theodore K. Koenig; Kaori Kawana; James E. Johnson; Aurélie Colomb; Pierre Tulet; Suzie Molloy; Ian E. Galbally; Rainer Volkamer; Anoop Mahajan; John W. Halfacre; Paul B. Shepson; Julia Schmale; Hélène Angot; Byron Blomquist; Matthew D. Shupe; Detlev Helmig; Junsu Gil; Meehye Lee; Sean C. Coburn; Ivan Ortega; Gao Chen; James Lee; Kenneth C. Aikin; David D. Parrish; John S. Holloway; Thomas B. Ryerson; Ilana B. Pollack; Eric J. Williams; Brian M. Lerner; Andrew J. Weinheimer; Teresa Campos; Frank M. Flocke; J. Ryan Spackman; Ilann Bourgeois; Jeff Peischl; Chelsea R. Thompson; Ralf M. Staebler; Amir A. Aliabadi; Wanmin Gong; Roeland Van Malderen; Anne M. Thompson; Ryan M. Stauffer; Debra E. Kollonige; Juan Carlos Gómez Martin; Masatomo Fujiwara; Katie Read; Matthew Rowlinson; Keiichi Sato; Junichi Kurokawa; Yoko Iwamoto; Fumikazu Taketani; Hisahiro Takashima; Mónica Navarro-Comas; Marios Panagi; Martin G. Schultz
  Earth System Science Data, 17, 9, 4901, 4932, Copernicus GmbH, 26 Sep. 2025, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal, Abstract. Studying tropospheric ozone over the remote areas of the planet, such as the open oceans and the polar regions, is crucial to understand the role of ozone as a global climate forcer and regulator of atmospheric oxidative capacity. A focus on the pristine oceanic and polar regions complements the available land-based datasets and provides insights into key photochemical and depositional loss processes that control the concentrations and spatiotemporal variability in ozone as well as the physicochemical mechanisms driving these patterns. However, an assessment of the role of ozone over the oceanic and polar regions has been hampered by a lack of comprehensive observational datasets. Here, we present the first comprehensive collection of ozone data over the oceans and the polar regions. The overall dataset consists of 77 ship cruises/buoy-based observations and 48 aircraft-based campaigns. The dataset, consisting of more than 630 000 independent ozone measurement data points covering the period from 1977 to 2022 and an altitude range from the surface to 5000 m (with a focus on the lowest 2000 m), allows systematic analyses of the spatiotemporal distribution and long-term trends over the 11 defined ocean/polar regions. The datasets from ships, buoys, and aircraft are complemented by ozonesonde data from 29 launch sites or field campaigns and by 21 non-polar and 17 polar ground-based station datasets. The datasets contain information on how long the observed air masses were isolated from land, as estimated by backward trajectories from the individual observation points. To extract observations representative of oceanic conditions, we recommend using a subset of the data with an isolation time of 72 h or longer, from the analysis with coincident radon observations. These filtered oceanic and polar data showed typically flat diurnal cycles at high latitudes, whereas daytime decreases in ozone (11 %–16 %) were observed at lower latitudes. The ship/buoy- and aircraft-based datasets presented here will supplement the land-based ones in the TOAR-II (Tropospheric Ozone Assessment Report Phase II) database to provide a fully global assessment of tropospheric ozone. The described dataset is available at https://doi.org/10.17596/0004044 (Kanaya et al., 2025).
• Justification for high-ascent attainment for balloon radiosonde soundings at GRUAN and other sites
  Masatomo Fujiwara; Bomin Sun; Anthony Reale; Domenico Cimini; Salvatore Larosa; Lori Borg; Christoph von Rohden; Michael Sommer; Ruud Dirksen; Marion Maturilli; Holger Vömel; Rigel Kivi; Bruce Ingleby; Ryan J. Kramer; Belay Demoz; Fabio Madonna; Fabien Carminati; Owen Lewis; Brett Candy; Christopher Thomas; David Edwards; Kensaku Shimizu; Peter Thorne
  Atmospheric Measurement Techniques, 07 Jul. 2025, [Peer-reviewed], [Lead author], ［Internationally co-authored］, [International Magazine]
  Scientific journal
• Geostationary Satellites Total Ozone Observations: First Results on Ground‐Based Networks Validation Efforts for TEMPO and GEMS
  Xiaoyi Zhao; Debora Griffin; Vitali Fioletov; Chris McLinden; Xiong Liu; Junsung Park; Irina Petropavlovskikh; Thomas F. Hanisco; James Szykman; Lukas Valin; Eric Baumann; Alexander Cede; Martin Tiefengraber; Manuel Gebetsberger; Itaru Uesato; Xiangdong Zheng; Soi Ahn; Limseok Chang; Won‐Jin Lee; Jae Hwan Kim; Hyunjin Lee; Kanghyun Baek; Alberto Redondas; Masatomo Fujiwara; Ting Wang; Michel Grutter; John C. Houck; David Haffner; Sum Chi Lee
  Geophysical Research Letters, 52, 12, American Geophysical Union (AGU), 14 Jun. 2025, [Peer-reviewed], ［Internationally co-authored］
  Scientific journal, Abstract
  
  The Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument, launched in April 2023, is North America's first geostationary air pollution monitoring satellite mission. Together with Asia's Geostationary Environment Monitoring Spectrometer (GEMS) launched in 2020 and Europe's upcoming Sentinel‐4, TEMPO contributes to nearly global coverage provided by geostationary satellite constellation. TEMPO and GEMS offer hourly, high‐resolution data of ozone surpassing the once‐daily observations of instruments like the TROPOspheric Monitoring Instrument (TROPOMI) in temporal resolution. This study presents TEMPO's total ozone data, demonstrating TEMPO's ability to observe sudden changes in ozone and UV index. Furthermore, TEMPO and GEMS measurements are validated using ground‐based monitoring networks (Brewer, Dobson, and Pandora). Results show good agreement but also highlight latitude‐dependent discrepancies between the satellite and ground‐based data sets (−2% to 2% for TEMPO, −1% to −3% for GEMS). Findings are further validated using TROPOMI data and reanalysis models.
• Investigating post-eruption amplified winter cooling in the Middle East and North Africa—unraveling ENSO and NAO dynamics
  Muhammad Mubashar Dogar; Masatomo Fujiwara; Masamichi Ohba; Mansour Almazroui
  Environmental Research Communications, 01 Apr. 2025, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  Scientific journal
• Changes in Equatorial Kelvin Wave Activity in the Upper Troposphere and Lower Stratosphere Associated with Interannual Variability of the Upper-Tropospheric Equatorial Zonal Wind
  Junko Suzuki; Noriyuki Nishi; Masatomo Fujiwara; Kunio Yoneyama
  Journal of Climate, 38, 3, 749, 759, American Meteorological Society, 01 Feb. 2025, [Peer-reviewed], [International Magazine]
  English, Scientific journal, We investigate the influence of the background wind regime on interannual variability in equatorial Kelvin waves (including both freely propagating ones and convectively coupled ones) in the upper troposphere and lower stratosphere using the ERA5 reanalysis data. We focus on variability in the number of Kelvin wave cases as a function of the background westerly wind that controls wave propagation, given by the zonal wind index (ZWI) in the equatorial eastern Pacific that is a measure of the strength of the upper branch of the Walker circulation in the Western Hemisphere. The ZWI correlates well with sea surface temperature in the Niño-3.4 region, though one-third of the peaks of negative ZWI (weak westerly) cases occur during seasons other than December–February which is the typical El Niño season. In the positive ZWI (stronger westerly) cases, both the convective activity over the western Pacific and the extratropical Rossby wave activity over the central and eastern Pacific are enhanced. Kelvin waves over the Western Hemisphere appear frequently at 200 hPa but barely reach 100 hPa due to the strong westerly wind below this level that prohibits upward wave propagation. In the negative ZWI period, the number of Kelvin wave cases at 200 hPa decreases due to weaker convection; Kelvin waves reach 100 hPa and propagate even further upward into the stratosphere. The increasing (decreasing) tendency of Kelvin waves already starts 6 months before the weakest (strongest) westerly wind month in the Western Hemisphere (i.e., the ENSO peak seasons).
  
  Significance Statement
  
  Equatorial Kelvin waves play a critical role in the upward transport of momentum driving the equatorial stratospheric circulation. Our results reveal that background winds in the upper troposphere and the lower stratosphere act as a filter for equatorial Kelvin waves, regulating the number of their packets propagating upward. An investigation of the role of Kelvin wave dissipation in the westerly duct region, i.e., in the upper troposphere over the equatorial eastern Pacific, is needed.
• Development of a Peltier-based chilled-mirror hygrometer, SKYDEW, for tropospheric and lower-stratospheric water vapor measurements
  Takuji Sugidachi; Masatomo Fujiwara; Kensaku Shimizu; Shin-Ya Ogino; Junko Suzuki; Ruud J. Dirksen
  Atmospheric Measurement Techniques, 18, 2, 509, 531, Copernicus GmbH, 28 Jan. 2025, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal, We have developed a Peltier-based non-cryogenic chilled-mirror hygrometer named SKYDEW to measure water vapor from the surface to the stratosphere. Several chamber experiments were conducted to investigate the characteristics and performance of the instrument under various conditions. The stability of the feedback controller that maintains the condensate on the mirror depends on the controller setting, the condensate condition, and the frost point in ambient air. The results of condensate observation by a microscope and proportional-integral-derivative (PID) tuning in a chamber were used to determine the PID parameters of the controller such that slight oscillations of the scattered light signal from the mirror and mirror temperature are retained. This allows for the detection of steep gradients in the humidity profile, which are otherwise not detected because of the slower response. The oscillation of the raw mirror temperature is smoothed with a golden point method that selects the equilibrium point of the frost layer. We further describe the details of the data processing and the uncertainty estimation for SKYDEW measurements in terms of the Global Climate Observing System (GCOS) Reference Upper-Air Network (GRUAN) requirements. The calibration uncertainty of the mirror temperature measurement is < 0.1 K for the entire temperature range from −95 to 40 °C. The total measurement uncertainty of SKYDEW measurements can exceed 0.5 K in regions where large oscillations of the mirror temperature remain. Intercomparisons with relative humidity (RH) sensors on radiosondes, the cryogenic frost point hygrometer (CFH), and the Aura Microwave Limb Sounder (MLS) were performed at various latitudes in the Northern Hemisphere to evaluate the performance of SKYDEW. These results show that SKYDEW can reliably measure atmospheric water vapor up to 25 km altitude. Data from several SKYDEW and CFH measurements predominantly agree within their respective uncertainties, although a systematic difference of ∼ 0.5 K between SKYDEW and CFH was found in the stratosphere, the reason for which is unknown. SKYDEW shows good agreement with Aura MLS for profiles that are not affected by contamination.
• Thermal Characteristics of the Extreme Cases of Tropopause Over the Tropics
  Pooja Purushotham; Sanjay Kumar Mehta; Saleem Ali; Masatomo Fujiwara; Susann Tegtmeier
  International Journal of Climatology, 44, 16, 5934, 5949, Wiley, 08 Nov. 2024, [Peer-reviewed], [International Magazine]
  English, Scientific journal, The anomalous variability of extreme cases of the tropical tropopause provides insight into the stratosphere‐troposphere exchange process crucial for understanding climate change. The present study analyses the extreme variability of the tropopause and its thermal structure over the tropics using GPS radio occultation data over the period 2006–2019. The extremely cold and warm tropopauses and extremely high and low tropopauses are identified based on the cold point tropopause temperature and height, respectively, when their values exceed two standard deviations with respect to their climatological means. The analyses revealed frequent occurrence of extreme cases of tropopause over the Atlantic Ocean compared to the Western Pacific Ocean. Individually, extremely warm and low cases occur more frequently over the subtropics, while extremely cold and high cases occur frequently over the deep tropics. These extreme cases pose different thermal structures bounded within the extremely low and high tropopauses throughout the tropics. The height difference between the extremely high and low tropopause cases is wider over the Atlantic Ocean and adjoining areas compared to the western Pacific Ocean. The temperature difference between the extremely warm and cold tropopause cases is higher in the Atlantic, Central Pacific, and Indonesian regions compared to the American, Indian Ocean, and western Pacific Ocean regions. The relationship between the El Niño Southern Oscillation (ENSO) phases and extreme tropopause cases is also investigated which reveals a higher occurrence of extremely high tropopause cases during the El Niño phase while low tropopause cases during the La Niña phase. Our analysis also revealed the thermal patterns of the extreme cases characterising colder and sharper tropopause over the convective regions compared to subsidence regions.
• Characteristics of convection and advection associated with the Asian Summer Monsoon Anticyclone
  P. P. Musaid; Sanjay Kumar Mehta; Susann Tegtmeier; Masatomo Fujiwara; Siddarth Shankar Das; Someshwar Das
  Climate Dynamics, 62, 9, 8929, 8945, Springer Science and Business Media LLC, 08 Aug. 2024, [Peer-reviewed], [International Magazine]
  English, Scientific journal, The Asian Summer Monsoon Anticyclone (ASMA) is a gateway for atmospheric pollutants transported to the upper troposphere and lower stratosphere (UTLS). Thus, it is necessary to understand the relative roles of vertical transport due to convection and horizontal transport due to advection in the formation and sustenance of the ASMA. Outgoing longwave radiation reveals that the ASMA region shows characteristic features associated with strong convective activity in its eastern (70°–120° E) part while subsidence dominates in the western (20°–70° E) part. Over the convective region, the convergence of latent heat flux extends from the Indian mainland (65°–110° E) to the west Pacific Warm Pool (WP) (110°–160° E). On average the ASMA region is characterized by a main convective outflow level at ~ 9 km. This level varies considerably with longitude being higher (~ 10.5 km) over the convective region and lower (~ 7 km) over the subsidence region. Furthermore, the mean convective outflow level is higher over the WP (11.5 km) region when compared to the Indian mainland (10 km) region. From the thermodynamic energy equation, we have calculated the convective and advective terms and found anomalously cold advection over the subsidence region and warm advection over the convective region. The warm advection over the convective region is split into two parts with the stronger one located over the Indian region and the weaker one over the WP region. Similarly, stronger convection occurs over the Indian mainland (convective term ~ 4 K/day) compared to the WP (~ 1 K/day). The cold advection over the subsidence region is mainly centered near 30° E longitude. The convection over the Indian region and the cold advection over the subsidence region as well as warm advection and convection over the WP region are associated. We find that the advective terms change in magnitude and shift together with the convective terms in response to signals of the El Nino Southern Oscillation and the Indian Ocean Dipole.
• Identification of the Asian summer monsoon anticyclone based on tropical easterly and subtropical westerly jets during active and break phases
  Padinhare Peediyekkal Musaid; Sanjay Kumar Mehta; Susann Tegtmeier; Masatomo Fujiwara; Pooja Purushotham; Sachin Philip Kakkanattu; Karaikkattu Benzigar Betsy; Chengannikkattu Jayakrishnan Seetha
  International Journal of Climatology, 44, 12, 4260, 4285, Wiley, Aug. 2024, [Peer-reviewed], [International Magazine]
  English, Scientific journal, The Asian summer monsoon anticyclone (ASMA) plays a vital role in the transport and redistribution of the tracers in the upper troposphere and lower stratosphere during transient monsoon conditions. The ASMA can be identified using various diagnostics such as winds and divergence, potential vorticity, the Montgomery stream function or geopotential height. Its representation based on the commonly‐used existing method that takes a climatological range of the geopotential height (GPH) at a given pressure level is not robust and fails in several circumstances. In this study, we propose a new GPH method to define the ASMA for the active and break phases of the monsoon based on the GPH values at the tropical easterly jet (TEJ) and subtropical westerly jet (STJ) locations. The proposed method compares the GPH values at the locations corresponding to the wind speed maxima of TEJ and STJ at 100 hPa with the maximum GPH at 100 hPa and selects the one with the minimum difference to define the ASMA extent. The same procedures were applied to obtain the ASMA extent at 150 hPa. The ASMA extents are obtained using the method proposed here and the existing fixed GPH method for the 30 active and 27 break phases from 2005 to 2023. The fixed GPH method provides a larger ASMA extent for 24 active and 21 break phases, which appears to be an unrealistic estimation compared to the proposed method. Our proposed method identifies the ASMA extent that is larger and centred around the Iranian side during the active phases while it is smaller and centred around the Tibetan side during the break phases. Furthermore, the minimum concentration of ozone (O₃), and maximum concentrations of carbon monoxide (CO) and water vapour (H₂O) are also found to be centred near the Iranian side during the active phases and on the Tibetan side during the break phases. The tracer concentrations are generally higher for CO, H₂O and O₃ during the active phase than in the break phase. Tracer concentrations within the ASMA extent using the fixed GPH method are higher for O₃ while lesser for CO and H₂O when compared to the proposed method.
• Climatology of the terms and variables of transformed Eulerian-mean (TEM) equations from multiple reanalyses: MERRA-2, JRA-55, ERA-Interim, and CFSR
  Masatomo Fujiwara; Patrick Martineau; Jonathon S. Wrigh; Marta Abalos; Petr Šácha; Yoshio Kawatani; Sean M. Davis; Thomas Birner; Beatriz M. Monge-Sanz
  Atmospheric Chemistry and Physics, 24, 7873, 7898, 10 Jul. 2024, [Peer-reviewed], [Lead author, Corresponding author], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal, A 30-year (1980–2010) climatology of the major variables and terms of the transformed Eulerian-mean (TEM) momentum and thermodynamic equations is constructed by using four global atmospheric reanalyses: the Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2); the Japanese 55-year Reanalysis (JRA-55); the European Centre for Medium-Range Weather Forecasts (ECMWF) interim reanalysis (ERA-Interim); and the Climate Forecast System Reanalysis (CFSR). Both the reanalysis ensemble mean (REM) and the differences in each reanalysis from the REM are investigated in the latitude–pressure domain for December–January–February and for June–July–August. For the REM investigation, two residual vertical velocities (the original one and one evaluated from residual meridional velocity) and two mass streamfunctions (from meridional and vertical velocities) are compared. Longwave (LW) radiative heating and shortwave (SW) radiative heating are also shown and discussed. For the TEM equations, the residual terms are also calculated and investigated for their potential usefulness, as the residual term for the momentum equation should include the effects of parameterized processes such as gravity waves, while that for the thermodynamic equation should indicate the analysis increment. Inter-reanalysis differences are investigated for the mass streamfunction, LW and SW heating, the two major terms of the TEM momentum equation (the Coriolis term and the Eliassen–Palm flux divergence term), and the two major terms of the TEM thermodynamic equation (the vertical temperature advection term and the total diabatic heating term). The spread among reanalysis TEM momentum balance terms is around 10 % in Northern Hemisphere winter and up to 50 % in Southern Hemisphere winter. The largest uncertainties in the thermodynamic equation (about 50 %) are found in the vertical advection, for which the structure is inconsistent with the differences in heating. The results shown in this paper provide basic information on the degree of agreement among recent reanalyses in the stratosphere and upper troposphere in the TEM framework.
• ENSO and NAO Linkage to Strong Volcanism and Associated Post‐Volcanic High‐Latitude Winter Warming
  Muhammad Mubashar Dogar; Masatomo Fujiwara; Ming Zhao; Masamichi Ohba; Yu Kosaka
  Geophysical Research Letters, 51, 1, American Geophysical Union (AGU), 08 Jan. 2024, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal, Abstract
  
  High‐latitude winter warming was observed following strong tropical volcanism, which has long been believed to be due to the volcanic‐induced positive North Atlantic Oscillation (NAO) phase. However, recent works argue that this warming is caused by El Niño–Southern Oscillation (ENSO) variability instead of volcanoes. Moreover, some studies further argue that El Niño and volcanoes work together to produce this post‐volcanic NAO winter warming. To better understand these arguments on post‐volcanic high‐latitude winter warming, we conducted ENSO‐preconditioned volcanic experiments. Our simulations strongly suggest that the post‐eruption Eurasian winter warming is caused by a post‐eruption positive NAO phase and not by coexisting ENSO‐preconditioned variability. Additionally, we find that the El Niño‐preconditioned volcanic eruption enhances the El Niño phase; however, the neutral and La Niña‐preconditioned eruptions do not lead to an ENSO–like response. These findings are helpful to better understand volcanic‐induced circulation impacts and have important implications for the interpretation of model results and post‐volcanic prediction.
• Development of a new particle imaging radiosonde with particle fall velocity measurements in clouds
  Kenji Suzuki; Yurika Hara; Takuji Sugidachi; Kensaku Shimizu; Masatomo Fujiwara
  SOLA (Scientific Online Letters on the Atmosphere), 19, 251, 254, Sep. 2023, [Peer-reviewed]
  English, Scientific journal
• LODEWAVE (LOng-Duration balloon Experiment of gravity WAVE over Antarctica)
  Tomikawa, Y; K. Sato; Y. Saito; I. Murata; N. Hirasawa; M. Kohma; K. Nakashino; D. Akita; T. Matsuo; M. Fujiwara; T. Kaho; L. Yoshida
  Journal of Evolving Space Activities, 1, Mar. 2023, [Peer-reviewed]
  English, International conference proceedings
• A Review of El Niño Southern Oscillation Linkage to Strong Volcanic Eruptions and Post-Volcanic Winter Warming
  Muhammad Mubashar Dogar; Leon Hermanson; Adam A. Scaife; Daniele Visioni; Ming Zhao; Ibrahim Hotei; Hans-F. Graf; Muhammad Ahmad Dogar; Mansour Almazroui; Masatomo Fujiwara
  Earth Systems and Environment, 7, 1, 15, 42, Springer Science and Business Media LLC, 07 Nov. 2022, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal
• Comparison of GRUAN data products for Meisei iMS-100 and Vaisala RS92 radiosondes at Tateno, Japan
  Shunsuke Hoshino; Takuji Sugidachi; Kensaku Shimizu; Eriko Kobayashi; Masatomo Fujiwara; Masami Iwabuchi
  Atmospheric Measurement Techniques, 15, 20, 5917, 5948, Copernicus GmbH, 19 Oct. 2022, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Abstract. A total of 99 dual soundings with Meisei iMS-100 radiosonde and Vaisala RS92 radiosondes were carried out at the Aerological Observatory of the Japan Meteorological Agency, known as Tateno (36.06∘ N, 140.13∘ E, 25.2 m; the World Meteorological Organization, WMO, station number 47646), from September 2017 to January 2020. Global Climate Observing System (GCOS) Reference Upper-Air Network (GRUAN) data products (GDPs) from both sets of radiosonde data for 59 flights were subsequently created using a documented processing programme along with the provision of optimal estimates for measurement uncertainty. Differences in radiosonde performance were then quantified using these GDPs. For daytime observations, the iMS-100 temperature is around 0.5 K cooler than RS92-GDP in the stratosphere, with significant differences in the upper troposphere and lower stratosphere in consideration of combined uncertainties. For nighttime observations, the difference is around −0.1 K, and data are mostly in agreement. For relative humidity (RH), iMS-100 is around 1 % RH–2 % RH higher in the troposphere and 1 % RH smaller in the stratosphere than RS92, but both GDPs are in agreement for most of the profile. The mean pressure difference is ≤0.1 hPa, the wind speed difference is from −0.04 to +0.14 m s−1, the wind direction difference is ≤6.4∘, and the root mean square vector difference (RMSVD) for wind is ≤1.04 m s−1.
• Balloon-borne aerosol–cloud interaction studies (BACIS): field campaigns to understand and quantify aerosol effects on clouds
  Varaha Ravi Kiran; Madineni Venkat Ratnam; Masatomo Fujiwara; Herman Russchenberg; Frank G. Wienhold; Bomidi Lakshmi Madhavan; Mekalathur Roja Raman; Renju Nandan; Sivan Thankamani Akhil Raj; Alladi Hemanth Kumar; Saginela Ravindra Babu
  Atmospheric Measurement Techniques, 15, 16, 4709, 4734, Copernicus GmbH, 19 Aug. 2022, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal, Abstract. A better understanding of aerosol–cloud interaction processes is importantto quantify the role of clouds and aerosols on the climate system. Therehave been significant efforts to explain the ways aerosols modulate cloudproperties. However, from the observational point of view, it is indeedchallenging to observe and/or verify some of these processes because nosingle instrument or platform has been proven to be sufficient. Discrimination betweenaerosol and cloud is vital for the quantification of aerosol–cloudinteraction. With this motivation, a set of observational field campaignsnamed balloon-borne aerosol–cloud interaction studies (BACIS) is proposedand conducted using balloon-borne in situ measurements in addition to theground-based (lidar; mesosphere, stratosphere and troposphere (MST) radar; lower atmospheric wind profiler; microwave radiometer; ceilometer) and space-borne(CALIPSO) remote sensing instruments from Gadanki (13.45∘ N, 79.2∘ E), India. So far, 15 campaigns have been conducted as a part of BACIS campaignsfrom 2017 to 2020. This paper presents the concept of the observationalapproach, lists the major objectives of the campaigns, describes theinstruments deployed, and discusses results from selected campaigns.Balloon-borne measurements of aerosol and cloud backscatter ratio and cloudparticle count are qualitatively assessed using the range-corrected datafrom simultaneous observations of ground-based and space-borne lidars.Aerosol and cloud vertical profiles obtained in multi-instrumental observationsare found to reasonably agree. Apart from this, balloon-borne profiling isfound to provide information on clouds missed by ground-based and/orspace-borne lidar. A combination of the Compact Optical Backscatter AerosoL Detector (COBALD) and Cloud Particle Sensor (CPS) sonde is employed for the first time in this study to discriminate cloud and aerosol in an in situ profile. A threshold value of the COBALD colour index (CI) for ice clouds is found to be between 18 and 20, and CI values for coarse-mode aerosol particles range between 11 and 15. Using the data from balloon measurements, the relationship between cloud and aerosol is quantified for the liquid clouds. A statistically significant slope (aerosol–cloud interaction index) of 0.77 found between aerosol backscatter and cloud particle count reveals the role of aerosol in the cloud activation process. In a nutshell, the results presented here demonstrate the observational approach to quantifying aerosol–cloud interactions.
• Cause of a Lower‐Tropospheric High‐Ozone Layer in Spring Over Hanoi
  S.‐Y. Ogino; K. Miyazaki; M. Fujiwara; M. I. Nodzu; M. Shiotani; F. Hasebe; J. Matsumoto; J. Witte; A. M. Thompson; H. A. Nguyen‐Thi; T. V. Nguyen
  Journal of Geophysical Research: Atmospheres, 127, 10, American Geophysical Union (AGU), 13 May 2022, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal
• SPARC Report No. 10, WCRP Report 6/2021
  Fujiwara, Masatomo; Manney, Gloria; Gray, Lesley; Wright, Jonathon
  SPARC Office, 2022
  English
• Lower-stratospheric aerosol measurements in eastward-shedding vortices over Japan from the Asian summer monsoon anticyclone during the summer of 2018
  Masatomo Fujiwara; Tetsu Sakai; Tomohiro Nagai; Koichi Shiraishi; Yoichi Inai; Sergey Khaykin; Haosen Xi; Takashi Shibata; Masato Shiotani; Laura L. Pan
  Atmospheric Chemistry and Physics, 21, 4, 3073, 3090, Copernicus GmbH, 01 Mar. 2021, [Peer-reviewed], [Lead author], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal, Abstract. Eastward air-mass transport from the Asian summer monsoon (ASM) anticyclone in the upper troposphere and lower stratosphere (UTLS) often involves eastward-shedding vortices, which can cover most of the Japanese archipelago. We investigated the aerosol characteristics of these vortices by analysing data from two lidar systems in Japan, at Tsukuba (36.1∘ N, 140.1∘ E) and Fukuoka (33.55∘ N, 130.36∘ E), during the summer of 2018. We observed several events with enhanced particle signals at Tsukuba at 15.5–18 km of altitude (at or above the local tropopause) during August–September 2018, with a backscattering ratio of ∼ 1.10 and particle depolarization of ∼ 5 % (i.e. not spherical, but more spherical than ice crystals). These particle characteristics may be consistent with those of solid aerosol particles, such as ammonium nitrate. Each event had a timescale of a few days. During the same study period, we also observed similar enhanced particle signals in the lower stratosphere at Fukuoka. The upper troposphere is often covered by cirrus clouds at both lidar sites. Backward trajectory calculations for these sites for days with enhanced particle signals in the lower stratosphere and days without indicate that the former air masses originated within the ASM anticyclone and the latter more from edge regions. Reanalysis carbon monoxide and satellite water vapour data indicate that eastward-shedding vortices were involved in the observed aerosol enhancements. Satellite aerosol data confirm that the period and latitudinal region were free from the direct influence of documented volcanic eruptions and high-latitude forest fires. Our results indicate that the Asian tropopause aerosol layer (ATAL) over the ASM region extends east towards Japan in association with the eastward-shedding vortices and that lidar systems in Japan can detect at least the lower-stratospheric portion of the ATAL during periods when the lower stratosphere is undisturbed by volcanic eruptions and forest fires. The upper-tropospheric portion of the ATAL is either depleted by tropospheric processes (convection and wet scavenging) during eastward transport or is obscured by much stronger cirrus cloud signals.
• Aerological Measurements
  Holger Vömel; Masatomo Fujiwara
  2021
• Balloon-borne radiation measurements demonstrate radiative forcing by water vapor and clouds
  Rolf Philipona; Andreas Kräuchi; Rigel Kivi; Thomas Peter; Martin Wild; Ruud Dirksen; Masatomo Fujiwara; Miho Sekiguchi; Dale F. Hurst; Ralf Becker
  Meteorologische Zeitschrift, 29, 6, 501, 509, Schweizerbart, 25 Nov. 2020, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Solar shortwave and terrestrial thermal longwave irradiance are measured at radiation sites at the Earth's surface and on satellite platforms high up in space, since many years. Radiation profiles through the Earth's atmosphere, however, have only sporadically been measured from enhanced upper-air radiosondes. Here we show profiles of solar and terrestrial radiation measured with balloon-borne radiometers through cloud-free and cloudy atmospheres, which reveal radiative effects of temperature, water vapor, ozone and clouds on downward and upward radiation. Shortwave radiation profiles show solar absorption in the free atmosphere and strong reflection in clouds and albedo effects on the ground and the atmosphere above. Longwave upward radiation profiles visualize terrestrial radiation emitted from the Earth's surface, which is partly absorbed and reemitted in the boundary layer and in the atmosphere by water vapor and other greenhouse gases. Longwave downward radiation profiles show the absorbed terrestrial radiation in the atmosphere and reveal the warming effect of increasing greenhouse gases, and by this visualize and demonstrate radiative forcing and a changing greenhouse effect by water vapor in the Earth's atmosphere. Longwave net radiation profiles show terrestrial emission into space to be reduced by water vapor and clouds. Measured radiation profiles are compared to numerically calculated radiation profiles.
• Assessment of Observational Evidence for Direct Convective Hydration of the Lower Stratosphere
  E. J. Jensen; Laura L. Pan; Shawn Honomichl; Glenn S. Diskin; Martina Krämer; Nicole Spelten; Gebhard Günther; Dale F. Hurst; Masatomo Fujiwara; Holger Vömel; Henry B. Selkirk; Junko Suzuki; Michael J. Schwartz; Jessica B. Smith
  Journal of Geophysical Research: Atmospheres, 125, 15, American Geophysical Union (AGU), 16 Aug. 2020, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal, In situ and remote sensing observations of water vapor are analyzed to assess the evidence for direct convective hydration of the lower stratosphere. We have examined several hundred balloon-borne and airborne in situ measurements of lower stratospheric humidity in the tropics and northern midlatitudes. We find that the tropical lower stratospheric H2O enhancements above the background occur quite infrequently, and the height of the enhancements is within about 1 km of the cold-point tropopause. Following Schwartz et al. (2013, https://doi.org/10.1002/grl.50421), we examine the anomalously high (above 8 ppmv) water vapor mixing ratios retrieved by the Aura Microwave Limb Sounder (MLS) at 100- and 82-hPa pressure levels, and we determine their vertical location relative to the local tropopause based on both Global Forecast System (GFS) operational analysis and the ERA5 reanalysis temperature data. We find that essentially all of the >8-ppmv MLS water vapor measurements over the extratropical North American monsoon region are above the relatively low lapse-rate tropopause in the region, and most are above the local cold-point tropopause. Over the Asian monsoon region, most (80/90%) of the high H2O values occur below the relatively high-altitude local lapse-rate/cold-point tropopause. Anomalously high MLS water vapor retrievals at 100 and 82 hPa almost never occur in the deep tropics. We show that this result is consistent with the in situ observations given the broad vertical averaging kernel of the MLS measurement. The available evidence suggests that direct hydration of the lower stratosphere is important over North America during the monsoon season but likely has limited impact in the tropics.
• Representation of the equatorial stratopause semiannual oscillation in global atmospheric reanalyses
  Yoshio Kawatani; Toshihiko Hirooka; Kevin Hamilton; Anne K. Smith; Masatomo Fujiwara
  Atmospheric Chemistry and Physics, 20, 14, 9115, 9133, Copernicus GmbH, 31 Jul. 2020, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal, Abstract. This paper reports on a project to compare the representation of the semiannual oscillation (SAO)
  in the equatorial stratosphere and lower mesosphere within six major global atmospheric reanalysis
  datasets and with recent satellite Sounding of the Atmosphere Using Broadband Emission Radiometry (SABER) and Microwave Limb Sounder (MLS) observations. All reanalyses have a good
  representation of the quasi-biennial oscillation (QBO) in the equatorial lower and middle
  stratosphere and each displays a clear SAO centered near the stratopause. However, the differences
  among reanalyses are much more substantial in the SAO region than in the QBO-dominated region. The
  degree of disagreement among the reanalyses is characterized by the standard deviation (SD) of the
  monthly mean zonal wind and temperature; this depends on latitude, longitude, height, and
  time. The zonal wind SD displays a prominent equatorial maximum that increases with height, while
  the temperature SD reaches a minimum near the Equator and is largest in the polar regions. Along the Equator,
  the zonal wind SD is smallest around the longitude of Singapore, where consistently high-quality
  near-equatorial radiosonde observations are available. Interestingly, the near-Singapore minimum
  in SD is evident to at least ∼3 hPa, i.e., considerably higher than the usual
  ∼10 hPa ceiling for in situ radiosonde observations. Our measurement of the
  agreement among the reanalyses shows systematic improvement over the period considered
  (1980–2016), up to near the stratopause. Characteristics of the SAO at 1 hPa, such as its
  detailed time variation and the displacement off the Equator of the zonal wind SAO amplitude
  maximum, differ significantly among the reanalyses. Disagreement among the reanalyses becomes
  still greater above 1 hPa. One of the reanalyses in our study also has a version produced
  without assimilating satellite observations, and a comparison of the SAO in these two versions
  demonstrates the very great importance of satellite-derived temperatures in the realistic analysis
  of the tropical upper stratospheric circulation.
• Use of automatic radiosonde launchers to measure temperature and humidity profiles from the GRUAN perspective
  Fabio Madonna; Rigel Kivi; Jean-Charles Dupont; Bruce Ingleby; Masatomo Fujiwara; Gonzague Romanens; Miguel Hernandez; Xavier Calbet; Marco Rosoldi; Aldo Giunta; Tomi Karppinen; Masami Iwabuchi; Shunsuke Hoshino; Christoph von Rohden; Peter William Thorne
  Atmospheric Measurement Techniques, 13, 7, 3621, 3649, Copernicus GmbH, 08 Jul. 2020, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal, Abstract. In the last two decades, technological progress has not only seen
  improvements to the quality of atmospheric upper-air observations but also
  provided the opportunity to design and implement automated systems able to
  replace measurement procedures typically performed manually. Radiosoundings,
  which remain one of the primary data sources for weather and climate
  applications, are still largely performed around the world manually,
  although increasingly fully automated upper-air observations are used, from
  urban areas to the remotest locations, which minimize operating costs and
  challenges in performing radiosounding launches. This analysis presents a
  first step to demonstrating the reliability of the automatic radiosonde
  launchers (ARLs) provided by Vaisala, Meteomodem and Meisei. The metadata
  and datasets collected by a few existing ARLs operated by the Global
  Climate Observing System (GCOS) Reference Upper-Air Network (GRUAN) certified or
  candidate sites (Sodankylä, Payerne, Trappes, Potenza) have been
  investigated and a comparative analysis of the technical performance (i.e.
  manual versus ARL) is reported. The performance of ARLs is evaluated as being
  similar or superior to those achieved with the traditional manual launches
  in terms of percentage of successful launches, balloon burst and ascent
  speed. For both temperature and relative humidity, the ground-check
  comparisons showed a negative bias of a few tenths of a degree and % RH,
  respectively. Two datasets of parallel soundings between manual and
  ARL-based measurements, using identical sonde models, provided by
  Sodankylä and Faa'a stations, showed mean differences between the ARL and
  manual launches smaller than ±0.2 K up to 10 hPa for the temperature
  profiles. For relative humidity, differences were smaller than 1 % RH for
  the Sodankylä dataset up to 300 hPa, while they were smaller than
  0.7 % RH for Faa'a station. Finally, the observation-minus-background
  (O–B) mean and root mean square (rms) statistics for German RS92 and RS41 stations, which
  operate a mix of manual and ARL launch protocols, calculated using the European Centre for Medium-Range Weather Forecasts (ECMWF)
  forecast model, are very similar, although RS41 shows larger rms(O–B)
  differences for ARL stations, in particular for temperature and wind. A
  discussion of the potential next steps proposed by GRUAN community and other
  parties is provided, with the aim to lay the basis for the elaboration of a
  strategy to fully demonstrate the value of ARLs and guarantee that the
  provided products are traceable and suitable for the creation of GRUAN data
  products.
• Surface temperature response to the major volcanic eruptions in multiple reanalysis data sets
  Masatomo Fujiwara; Patrick Martineau; Jonathon S. Wright
  Atmospheric Chemistry and Physics, 20, 1, 345, 374, Copernicus GmbH, 10 Jan. 2020, [Peer-reviewed], [Lead author], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal, Abstract. The global response of air temperature at 2 m above
  the surface to the eruptions of Mount Agung in March 1963, El Chichón in
  April 1982, and Mount Pinatubo in June 1991 is investigated using 11 global
  atmospheric reanalysis data sets (JRA-55, JRA-25, MERRA-2, MERRA,
  ERA-Interim, ERA-40, CFSR, NCEP-NCAR R-1, 20CR version 2c, ERA-20C, and
  CERA-20C). Multiple linear regression (MLR) is applied to the monthly mean
  time series of temperature for two periods – 1980–2010 (for 10 reanalyses) and 1958–2001 (for 6 reanalyses) – by considering explanatory factors of
  seasonal harmonics, linear trends, quasi-biennial oscillation (QBO), solar
  cycle, tropical sea surface temperature (SST) variations in the Pacific,
  Indian, and Atlantic Oceans, and Arctic SST variations. Empirical orthogonal
  function (EOF) analysis is applied to these climatic indices to obtain a set
  of orthogonal indices to be used for the MLR. The residuals of the MLR are
  used to define the volcanic signals for the three eruptions separately.
  First, area-averaged time series of the residuals are investigated and
  compared with the results from previous studies. Then, the geographical
  distribution of the response during the peak cooling period after each
  eruption is investigated. In general, different reanalyses show similar
  geographical patterns of the response, but with the largest differences in
  the polar regions. The Pinatubo response shows the largest average cooling in
  the 60∘ N–60∘ S region among the three eruptions, with
  a peak cooling of 0.10–0.15 K. The El Chichón response shows slightly
  larger cooling in the NH than in the Southern Hemisphere (SH), while the
  Agung response shows larger cooling in the SH. These hemispheric differences
  are consistent with the distribution of stratospheric aerosol optical depth
  after these eruptions; however, the peak cooling after these two eruptions
  is comparable in magnitude to unexplained cooling events in other periods
  without volcanic influence. Other methods in which the MLR model is used
  with different sets of indices are also tested, and it is found that careful
  treatment of tropical SST variability is necessary to evaluate the surface
  response to volcanic eruptions in observations and reanalyses.
• Large-and-Sparse-particle Clouds (LSC): Clouds which are subvisible for space-borne lidar and observable for space-borne cloud radar
  Suginori Iwasaki; Takafumi Seguchi; Hajime Okamoto; Kaori Sato; Shuichiro Katagiri; Masatomo Fujiwara; Takashi Shibata; Kazuhisa Tsuboki; Takashi Ono; Takuji Sugidachi
  Polar Science, 21, 117, 123, Sep. 2019, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal
• Comparison of equatorial wave activity in the tropical tropopause layer and stratosphere represented in reanalyses
  Young-Ha Kim; George N. Kiladis; John R. Albers; Juliana Dias; Masatomo Fujiwara; James A. Anstey; In-Sun Song; Corwin J. Wright; Yoshio Kawatani; François Lott; Changhyun Yoo
  Atmospheric Chemistry and Physics, 19, 15, 10027, 10050, Copernicus GmbH, 09 Aug. 2019, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal, Abstract. Equatorial Kelvin and mixed Rossby–gravity (MRG) waves in the tropical tropopause layer and stratosphere represented in recent reanalyses for the period of 1981–2010 are compared in terms of spectral characteristics, spatial structures, long-term variations, and their forcing of the quasi-biennial oscillation (QBO).
  For both wave types, the spectral distributions are broadly similar among most of the reanalyses, while the peak amplitudes exhibit considerable spread.
  The longitudinal distributions and spatial patterns of wave perturbations show reasonable agreement between the reanalyses.
  A few exceptions to the similarity of the spectral shapes and spatial structures among them are also noted.
  While the interannual variations of wave activity appear to be coherent for both the Kelvin and MRG waves, there is substantial variability in long-term trends among the reanalyses.
  Most of the reanalyses which assimilate satellite data exhibit large increasing trends in wave variance (∼15 %–50 % increase in 30 years at 100–10 hPa), whereas one reanalysis (Japanese 55-year Reanalysis assimilating conventional observations only; JRA-55C) produced without satellite data does not.
  Several discontinuities are found around 1998 in the time series of the Kelvin and MRG wave variances, which manifest in different ways depending on the reanalysis, and are indicative of impacts of the transition of satellite measurements during that year.
  The equatorial wave forcing of the QBO, estimated by the Eliassen–Palm (EP) flux divergence, occurs in similar phase-speed ranges in the lower stratosphere among the reanalyses.
  However, the EP flux and its divergence are found to be dependent on the zonal-mean winds represented in reanalyses, exhibiting different magnitudes, altitudes, and phase-speed ranges of the Kelvin wave forcing between the reanalyses, especially at 20–10 hPa.
  In addition, at around 20 hPa, a wave signal which appears only in easterly mean winds with westward phase speeds is found and discussed.
• Comparison of the GRUAN data products for Meisei RS-11G and Vaisala RS92-SGP radiosondes at Tateno (36.06° N, 140.13° E), Japan
  Eriko Kobayashi; Shunsuke Hoshino; Masami Iwabuchi; Takuji Sugidachi; Kensaku Shimizu; Masatomo Fujiwara
  Atmospheric Measurement Techniques, 12, 6, 3039, 3065, Copernicus GmbH, 04 Jun. 2019, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Abstract. A total of 87 dual flights of Meisei RS-11G radiosondes
  and Vaisala RS92-SGP radiosondes were carried out at the Aerological
  Observatory of the Japan Meteorological Agency (36.06∘ N,
  140.13∘ E, 25.2 m) from April 2015 to June 2017. Global
  Climate Observing System (GCOS) Reference Upper-Air Network (GRUAN) data
  products from both sets of radiosonde data for 52 flights were subsequently
  created using a documented processing program along with the provision of
  optimal estimates for measurement uncertainty. Differences in the
  performance of the radiosondes were then quantified using the GRUAN data
  products. The temperature measurements of RS-11G were, on average,
  0.4 K
  lower than those of RS92-SGP in the stratosphere for daytime observations.
  The relative humidity measurements of RS-11G were, on average, 2 % RH (relative humidity) lower
  than those of RS92-SGP under 90 % RH–100 % RH conditions, while RS-11G gave on
  average 5 % RH higher values than RS92-SGP under ≤50 % RH
  conditions. The results from a dual flight of RS-11G and a cryogenic
  frost point hygrometer (CFH) also showed that RS-11G gave 1 % RH–10 % RH higher
  values than the CFH in the troposphere. Differences between the RS-11G and
  RS92-SGP temperature and relative humidity measurements, based on combined
  uncertainties, were also investigated to clarify major influences behind the
  differences. It was found that temperature differences in the stratosphere
  during daytime observation were within the range of uncertainty (k=2),
  and that sensor orientation is the major source of uncertainty in the
  RS92-SGP temperature measurement, while sensor albedo is the major source of
  uncertainty for RS-11G. The relative humidity difference in the troposphere
  was larger than the uncertainty (k=2) after the radiosondes had passed
  through the cloud layer, and the temperature–humidity dependence correction
  was the major source of uncertainty in RS-11G relative humidity measurement.
  Uncertainties for all soundings were also statistically investigated. Most
  nighttime temperature measurements for pressures of >10 hPa
  were in agreement, while relative humidity in the middle troposphere
  exhibited significant differences. Around half of all daytime temperature
  measurements at pressures of ≤150 hPa and relative humidity
  measurements around the 500 hPa level were not in agreement.
• Influence of ENSO and MJO on the zonal structure of tropical tropopause inversion layer using high-resolution temperature profiles retrieved from COSMIC GPS Radio Occultation
  Noersomadi; Toshitaka Tsuda; Masatomo Fujiwara
  Atmospheric Chemistry and Physics, 19, 10, 6985, 7000, Copernicus GmbH, 24 May 2019, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal, Abstract. Using COSMIC GPS Radio Occultation (RO) observations from
  January 2007 to December 2016, we retrieved temperature profiles with the
  height resolution of about 0.1 km in the upper troposphere and lower
  stratosphere (UTLS). We investigated the distribution of static stability
  (N2) and the zonal structure of the tropopause inversion layer (TIL) in
  the tropics, where a large change in the temperature gradient occurs associated
  with sharp variations in N2. We show the variations in the mean N2
  profiles in coordinates relative to the cold-point tropopause (CPT). A very
  thin (<1 km) layer is found with average maximum N2 in the
  range of 11.0–12.0×10-4 s−2. The mean and standard
  deviation of TIL sharpness, defined as the difference between the maximum
  N2 (max⁡N2) and minimum N2 (min⁡N2)
  within ±1 km of the CPT, is (10.5±3.7)×10-4 s−2. The max⁡N2 is typically located within 0.5 km above CPT. We focused on the variation in TIL sharpness in two longitude regions,
  90–150∘ E (Maritime Continent; MC) and 170–230∘ E
  (Pacific Ocean; PO), with different land–sea distribution. Seasonal
  variations in TIL sharpness and thickness were related to the deep convective
  activity represented by low outgoing longwave radiation (OLR) during the
  Australian and Asian monsoons. The deviation from the mean sharpness
  (sharpness anomaly) was out of phase with the OLR anomaly in both the MC and
  PO. The correlation between the sharpness anomaly over the MC and PO and the sea
  surface temperature (SST) Niño 3.4 index was −0.66 and +0.88,
  respectively. During La Niña (SST Niño 3.4 <-0.5 K) in the MC and
  El Niño (SST Niño 3.4 >+0.5 K) in the PO, warmer SSTs in the MC
  and PO produce more active deep convection that tends to force the air upward
  to the tropopause layer and increase the temperature gradient there. The
  intraseasonal variation in sharpness anomaly during slow and fast episodes
  of the Madden–Julian Oscillation (MJO) demonstrates that eastward
  propagation of the positive sharpness anomaly is associated with organized deep
  convection. Deep convection during MJO will tend to decrease N2 below
  CPT and increase N2 above CPT, thus enlarging the TIL sharpness. Convective
  activity in the tropics is a major control on variations in tropopause
  sharpness at intraseasonal to interannual timescales.
• Radiosondes Show That After Decades of Cooling, the Lower Stratosphere Is Now Warming
  Rolf Philipona; Carl Mears; Masatomo Fujiwara; Pierre Jeannet; Peter Thorne; Greg Bodeker; Leopold Haimberger; Maxime Hervo; Christoph Popp; Gonzague Romanens; Wolfgang Steinbrecht; Rene Stübi; Roeland Van Malderen
  Journal of Geophysical Research: Atmospheres, 123, 22, American Geophysical Union (AGU), 27 Nov. 2018, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Since the mid-twentieth century, radiosonde and satellite measurements show that the troposphere has warmed and the stratosphere has cooled. These changes are primarily due to increasing concentrations of well-mixed greenhouse gases and the depletion of stratospheric ozone. In response to continued greenhouse gas increases and stratospheric ozone depletion, climate models project continued tropospheric warming and stratospheric cooling over the coming decades. Global average satellite observations of lower stratospheric temperatures exhibit no significant trends since the turn of the century. In contrast, an analysis of vertically resolved radiosonde measurements from 60 stations shows an increase of lower stratospheric temperature since the turn of the century at altitudes between 15 and 30 km and over most continents. Trend estimates are somewhat sensitive to homogeneity assessment choices, but all investigated radiosonde data sets suggest a change from late twentieth century cooling to early 21st century warming in the lower stratosphere, which is consistent with a reversal from ozone depletion to recovery from the effects of ozone-depleting substances. In comparison, satellite observations at the radiosonde locations show only minor early 21st century warming, possibly due to the compensating effects of continued cooling above the radiosonde altitude range.
• Zonal-mean data set of global atmospheric reanalyses on pressure levels
  Patrick Martineau; Jonathon S. Wright; Nuanliang Zhu; Masatomo Fujiwara
  Earth System Science Data, 10, 4, 1925, 1941, Copernicus GmbH, 18 Oct. 2018, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal, Abstract. This data set, which is prepared for the Stratosphere–troposphere Processes And their Role in Climate (SPARC) Reanalysis
  Intercomparison Project (S-RIP), provides several zonal-mean diagnostics
  computed from reanalysis data on pressure levels. Diagnostics are currently
  provided for a variety of reanalyses, including ERA-40, ERA-Interim, ERA-20C,
  NCEP–NCAR, NCEP–DOE, CFSR, 20CR v2 and v2c, JRA-25, JRA-55, JRA-55C,
  JRA-55AMIP, MERRA, and MERRA-2. The data set will be expanded to include
  additional reanalyses as they become available. Basic dynamical variables
  (such as temperature, geopotential height, and three-dimensional winds) are
  provided in addition to a complete set of terms from the Eulerian-mean and
  transformed-Eulerian-mean momentum equations. Total diabatic heating and its
  long-wave and shortwave components are included as availability permits,
  along with heating rates diagnosed from the basic dynamical variables using
  the zonal-mean thermodynamic equation. Two versions of the data set are
  provided, one that uses horizontal and vertical grids provided by the various
  reanalysis centers and another that uses a common grid (CG) to facilitate
  comparison among data sets. For the common grid, all diagnostics are
  interpolated horizontally onto a regular 2.5∘×2.5∘ grid
  for a subset of pressure levels that are common among all included
  reanalyses. The dynamical
  (Martineau, 2017, https://doi.org/10.5285/b241a7f536a244749662360bd7839312)
  and diabatic
  (Wright, 2017, https://doi.org/10.5285/70146c789eda4296a3c3ab6706931d56)
  variables are archived and maintained by the Centre for Environmental Data
  Analysis (CEDA).
• Balloon-borne tropospheric CO2 observations over the equatorial eastern and western Pacific
  Yoichi Inai; Shuji Aoki; Hideyuki Honda; Hiroshi Furutani; Yutaka Matsumi; Mai Ouchi; Satoshi Sugawara; Fumio Hasebe; Mitsuo Uematsu; Masatomo Fujiwara
  Atmospheric Environment, 184, 24, 36, Jul. 2018, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Coordinated Upper-Troposphere-to-Stratosphere Balloon Experiment in Biak
  F. Hasebe; S. Aoki; S. Morimoto; Y. Inai; T. Nakazawa; S. Sugawara; C. Ikeda; H. Honda; H. Yamazaki; Halimurrahman; N. Komala; F. A. Putri; A. Budiyono; M. Soedjarwo; S. Ishidoya; S. Toyoda; T. Shibata; M. Hayashi; N. Eguchi; N. Nishi; M. Fujiwara; S.-Y. Ogino; M. Shiotani; T. Sugidachi
  Bulletin of the American Meteorological Society, 99, 6, 1213, 1230, Jun. 2018, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal
• Representation of solar tides in the stratosphere and lower mesosphere in state-of-the-art reanalyses and in satellite observations
  Takatoshi Sakazaki; Masatomo Fujiwara; Masato Shiotani
  Atmospheric Chemistry and Physics, 18, 2, 1437, 1456, 01 Feb. 2018, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• First Reprocessing of Southern Hemisphere Additional Ozonesondes (SHADOZ) Ozone Profiles (1998–2016): 2. Comparisons With Satellites and Ground‐Based Instruments
  Anne M. Thompson; Jacquelyn C. Witte; Chance Sterling; Allen Jordan; Bryan J. Johnson; Samuel J. Oltmans; Masatomo Fujiwara; Holger Vömel; Marc Allaart; Ankie Piters; Gert J. R. Coetzee; Françoise Posny; Ernesto Corrales; Jorge Andres Diaz; Christian Félix; Ninong Komala; Nga Lai; H. T. Ahn Nguyen; Matakite Maata; Francis Mani; Zamuna Zainal; Shin‐ya Ogino; Francisco Paredes; Tercio Luiz Bezerra Penha; Francisco Raimundo Silva; Sukarni Sallons‐Mitro; Henry B. Selkirk; F. J. Schmidlin; Rene Stübi; Kennedy Thiongo
  Journal of Geophysical Research: Atmospheres, 122, 23, 16 Dec. 2017, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal
• Climatology and interannual variability of dynamic variables in multiple reanalyses evaluated by the SPARC Reanalysis Intercomparison Project (S-RIP)
  Craig S. Long; Masatomo Fujiwara; Sean Davis; Daniel M. Mitchell; Corwin J. Wright
  Atmospheric Chemistry and Physics, 17, 23, 14593, 14629, 07 Dec. 2017, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal
• Assessment of upper tropospheric and stratospheric water vapor and ozone in reanalyses as part of S-RIP
  Sean M. Davis; Michaela I. Hegglin; Masatomo Fujiwara; Rossana Dragani; Yayoi Harada; Chiaki Kobayashi; Craig Long; Gloria L. Manney; Eric R. Nash; Gerald L. Potter; Susann Tegtmeier; Tao Wang; Krzysztof Wargan; Jonathon S. Wright
  Atmospheric Chemistry and Physics, 17, 20, 12743, 12778, 26 Oct. 2017, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal
• Validation of 10-year SAO OMI Ozone Profile (PROFOZ) product using ozonesonde observations
  Guanyu Huang; Xiong Liu; Kelly Chance; Kai Yang; Pawan K. Bhartia; Zhaonan Cai; Marc Allaart; Gérard Ancellet; Bertrand Calpini; Gerrie J. R. Coetzee; Emilio Cuevas-Agulló; Manuel Cupeiro; Hugo De Backer; Manvendra K. Dubey; Henry E. Fuelberg; Masatomo Fujiwara; Sophie Godin-Beekmann; Tristan J. Hall; Bryan Johnson; Everette Joseph; Rigel Kivi; Bogumil Kois; Ninong Komala; Gert König-Langlo; Giovanni Laneve; Thierry Leblanc; Marion Marchand; Kenneth R. Minschwaner; Gary Morris; Michael J. Newchurch; Shin-Ya Ogino; Nozomu Ohkawara; Ankie J. M. Piters; Françoise Posny; Richard Querel; Rinus Scheele; Frank J. Schmidlin; Russell C. Schnell; Otto Schrems; Henry Selkirk; Masato Shiotani; Pavla Skrivánková; René Stübi; Ghassan Taha; David W. Tarasick; Anne M. Thompson; Valérie Thouret; Matthew B. Tully; Roeland Van Malderen; Holger Vömel; Peter von der Gathen; Jacquelyn C. Witte; Margarita Yela
  Atmospheric Measurement Techniques, 10, 7, 2455, 2475, 13 Jul. 2017, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal
• The Asia-Pacific’s role in the emerging solar geoengineering debate
  Masahiro Sugiyama; Shinichiro Asayama; Atsushi Ishii; Takanobu Kosugi; John C. Moore; Jolene Lin; Penehuro F. Lefale; Wil Burns; Masatomo Fujiwara; Arunabha Ghosh; Joshua Horton; Atsushi Kurosawa; Andy Parker; Michael Thompson; Pak-Hang Wong; Lili Xia
  Climatic Change, 143, 1-2, 1, 12, Jul. 2017, [Peer-reviewed], ［Internationally co-authored］
  English, Scientific journal
• First reprocessing of Southern Hemisphere ADditional OZonesondes (SHADOZ) profile records (1998-2015): 1. Methodology and evaluation
  Jacquelyn C. Witte; Anne M. Thompson; Herman G. J. Smit; Masatomo Fujiwara; Françoise Posny; Gert J. R. Coetzee; Edward T. Northam; Bryan J. Johnson; Chance W. Sterling; Maznorizan Mohamad; Shin-Ya Ogino; Allen Jordan; Francisco R. da Silva
  Journal of Geophysical Research: Atmospheres, 122, 12, 6611, 6636, 27 Jun. 2017, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal
• Introduction to the SPARC Reanalysis Intercomparison Project (S-RIP) and overview of the reanalysis systems
  Masatomo Fujiwara; Jonathon S. Wright; Gloria L. Manney; Lesley J. Gray; James Anstey; Thomas Birner; Sean Davis; Edwin P. Gerber; V. Lynn Harvey; Michaela I. Hegglin; Cameron R. Homeyer; John A. Knox; Kirstin Krüger; Alyn Lambert; Craig S. Long; Patrick Martineau; Andrea Molod; Beatriz M. Monge-Sanz; Michelle L. Santee; Susann Tegtmeier; Simon Chabrillat; David G. H. Tan; David R. Jackson; Saroja Polavarapu; Gilbert P. Compo; Rossana Dragani; Wesley Ebisuzaki; Yayoi Harada; Chiaki Kobayashi; Will McCarty; Kazutoshi Onogi; Steven Pawson; Adrian Simmons; Krzysztof Wargan; Jeffrey S. Whitaker; Cheng-Zhi Zou
  Atmospheric Chemistry and Physics, 17, 2, 1417, 1452, 31 Jan. 2017, [Peer-reviewed], [Lead author], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal
• Transdisciplinary co-design of scientific research agendas: 40 research questions for socially relevant climate engineering research
  Masahiro Sugiyama; Shinichiro Asayama; Takanobu Kosugi; Atsushi Ishii; Seita Emori; Jiro Adachi; Keigo Akimoto; Masatomo Fujiwara; Tomoko Hasegawa; Yasushi Hibi; Kimiko Hirata; Toru Ishii; Takeshi Kaburagi; Yuki Kita; Shigeki Kobayashi; Atsushi Kurosawa; Manabu Kuwata; Kooiti Masuda; Makoto Mitsui; Taku Miyata; Hiroshi Mizutani; Sumie Nakayama; Kazuyo Oyamada; Takaaki Sashida; Miho Sekiguchi; Kiyoshi Takahashi; Yukari Takamura; Junichi Taki; Taketoshi Taniguchi; Hiroyuki Tezuka; Takahiro Ueno; Shingo Watanabe; Rie Watanabe; Naoyuki Yamagishi; Go Yoshizawa
  Sustainability Science, 12, 1, 31, 44, Jan. 2017, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Development of a cloud particle sensor for radiosonde sounding
  Masatomo Fujiwara; Takuji Sugidachi; Toru Arai; Kensaku Shimizu; Mayumi Hayashi; Yasuhisa Noma; Hideaki Kawagita; Kazuo Sagara; Taro Nakagawa; Satoshi Okumura; Yoichi Inai; Takashi Shibata; Suginori Iwasaki; Atsushi Shimizu
  Atmospheric Measurement Techniques, 9, 12, 5911, 5931, 09 Dec. 2016, [Peer-reviewed], [Lead author], [International Magazine]
  English, Scientific journal
• Influence of topography on temperature variations in the tropical tropopause layer
  Hiroyasu Kubokawa; Masaki Satoh; Junko Suzuki; Masatomo Fujiwara
  Journal of Geophysical Research: Atmospheres, 121, 19, 11556, 11574, 16 Oct. 2016, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• The Stratospheric Water and Ozone Satellite Homogenized (SWOOSH) database:a long-term database for climate studies
  Sean M. Davis; Karen H. Rosenlof; Birgit Hassler; Dale F. Hurst; William G. Read; Holger Vömel; Henry Selkirk; Masatomo Fujiwara; Robert Damadeo
  Earth System Science Data, 8, 2, 461, 490, 28 Sep. 2016, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal
• Representation of the tropical stratospheric zonal wind in global atmospheric reanalyses
  Yoshio Kawatani; Kevin Hamilton; Kazuyuki Miyazaki; Masatomo Fujiwara; James A. Anstey
  Atmospheric Chemistry and Physics, 16, 11, 6681, 6699, 2016, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal
• Signatures of naturally induced variability in the atmosphere using multiple reanalysis datasets
  D. M. Mitchell; L. J. Gray; M. Fujiwara; T. Hibino; J. A. Anstey; W. Ebisuzaki; Y. Harada; C. Long; S. Misios; P. A. Stott; D. Tan
  QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, 141, 691, 2011, 2031, Jul. 2015, [Peer-reviewed]
  English, Scientific journal
• Effect of recent minor volcanic eruptions on temperatures in the upper troposphere and lower stratosphere
  Sanjay Kumar Mehta; Masatomo Fujiwara; Toshitaka Tsuda; Jean-Paul Vernier
  JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS, 129, 99, 110, Jul. 2015, [Peer-reviewed]
  English, Scientific journal
• Global temperature response to the major volcanic eruptions in multiple reanalysis data sets
  M. Fujiwara; T. Hibino; S. K. Mehta; L. Gray; D. Mitchell; J. Anstey
  ATMOSPHERIC CHEMISTRY AND PHYSICS, 15, 23, 13507, 13518, 2015, [Peer-reviewed]
  English, Scientific journal
• Altitude misestimation caused by the Vaisala RS80 pressure bias and its impact on meteorological profiles
  Y. Inai; M. Shiotani; M. Fujiwara; F. Hasebe; H. Voemel
  Atmospheric Measurement Techniques, 8, 10, 4043, 4054, 2015, [Peer-reviewed]
  English, Scientific journal
• The occurrence of cirrus clouds associated with eastward propagating equatorialn = 0 inertio-gravity and Kelvin waves in November 2011 during the CINDY2011/DYNAMO campaign
  Suzuki Junko; Fujiwara Masatomo; Nishizawa Tomoaki; Shirooka Ryuichi; Yoneyama Kunio; Katsumata Masaki; Matsui Ichiro; Sugimoto Nobuo
  Journal of Geophysical Research: Atmospheres, 118, 23, 12, 12, American Geophysical Union, 16 Dec. 2013
  English
• The occurrence of cirrus clouds associated with eastward propagating equatorial n = 0 inertio-gravity and Kelvin waves in November 2011 during the CINDY2011/DYNAMO campaign
  Junko Suzuki; Masatomo Fujiwara; Tomoaki Nishizawa; Ryuichi Shirooka; Kunio Yoneyama; Masaki Katsumata; Ichiro Matsui; Nobuo Sugimoto
  Journal of Geophysical Research Atmospheres, 118, 23, 12941, 12947, Blackwell Publishing Ltd, 16 Dec. 2013, [Peer-reviewed]
  English, Scientific journal
• Interpretation of the vertical structure and seasonal variation of the diurnal migrating tide from the troposphere to the lower mesosphere
  T. Sakazaki; M. Fujiwara; X. Zhang
  JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS, 105, 66, 80, Dec. 2013, [Peer-reviewed]
  English, Scientific journal
• Comparison of ozone profiles between Superconducting Submillimeter-Wave Limb-Emission Sounder and worldwide ozonesonde measurements
  Koji Imai; Masatomo Fujiwara; Yoichi Inai; Naohiro Manago; Makoto Suzuki; Takuki Sano; Chihiro Mitsuda; Yoko Naito; Fumio Hasebe; Takashi Koide; Masato Shiotani
  Journal of Geophysical Research Atmospheres, 118, 22, 12755, 12765, Blackwell Publishing Ltd, 27 Nov. 2013, [Peer-reviewed]
  English, Scientific journal
• Validation of ozone data from the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES)
  Koji Imai; Naohiro Manago; Chihiro Mitsuda; Yoko Naito; Eriko Nishimoto; Takatoshi Sakazaki; Masatomo Fujiwara; Lucien Froidevaux; Thomas Von Clarmann; Gabriele P. Stiller; Donal P. Murtagh; Ping-Ping Rong; Martin G. Mlynczak; Kaley A. Walker; Douglas E. Kinnison; Hideharu Akiyoshi; Tetsu Nakamura; Takayuki Miyasaka; Toshiyuki Nishibori; Satoko Mizobuchi; Ken-Ichi Kikuchi; Hiroyuki Ozeki; Chikako Takahashi; Hiroo Hayashi; Takuki Sano; Makoto Suzuki; Masahiro Takayanagi; Masato Shiotani
  Journal of Geophysical Research Atmospheres, 118, 11, 5750, 5769, Blackwell Publishing Ltd, 16 Jun. 2013, [Peer-reviewed]
  English, Scientific journal
• Correction of the Stepwise Change Observed at 0 degrees C in Meisei RS2-91, RS-01G, and RS-06G Radiosonde Relative Humidity Profiles
  Takuji Sugidachi; Masatomo Fujiwara
  JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN, 91, 3, 323, 336, Jun. 2013, [Peer-reviewed]
  English, Scientific journal
• Ozone variations over the northern subtropical region revealed by ozonesonde observations in Hanoi
  S. Y. Ogino; M. Fujiwara; M. Shiotani; F. Hasebe; J. Matsumoto; Thuy Ha T. Hoang; Tan Thanh T. Nguyen
  Journal of Geophysical Research Atmospheres, 118, 8, 3245, 3257, Blackwell Publishing Ltd, 27 Apr. 2013, [Peer-reviewed]
  English, Scientific journal
• Diurnal ozone variations in the stratosphere revealed in observations from the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on board the International Space Station (ISS)
  Takatoshi Sakazaki; Masatomo Fujiwara; Chihiro Mitsuda; Koji Imai; Naohiro Manago; Yoko Naito; Tetsu Nakamura; Hideharu Akiyoshi; Douglas Kinnison; Takuki Sano; Makoto Suzuki; Masato Shiotani
  Journal of Geophysical Research Atmospheres, 118, 7, 2991, 3006, Blackwell Publishing Ltd, 16 Apr. 2013, [Peer-reviewed]
  English, Scientific journal
• Ozone variations over the northern subtropical region revealed by ozonesonde observations in Hanoi
  S. -Y. Ogino; M. Fujiwara; M. Shiotani; F. Hasebe; J. Matsumoto; Thuy Ha T. Hoang; Tan Thanh T. Nguyen
  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 118, 8, 3245, 3257, Apr. 2013, [Peer-reviewed]
  English, Scientific journal
• Validation of stratospheric and mesospheric ozone observed by SMILES from International Space Station
  Y. Kasai; H. Sagawa; D. Kreyling; E. Dupuy; P. Baron; J. Mendrok; K. Suzuki; T. O. Sato; T. Nishibori; S. Mizobuchi; K. Kikuchi; T. Manabe; H. Ozeki; T. Sugita; M. Fujiwara; Y. Irimajiri; K. A. Walker; P. F. Bernath; C. Boone; G. Stiller; T. von Clarmann; J. Orphal; J. Urban; D. Murtagh; E. J. Llewellyn; D. Degenstein; A. E. Bourassa; N. D. Lloyd; L. Froidevaux; M. Birk; G. Wagner; F. Schreier; J. Xu; P. Vogt; T. Trautmann; M. Yasui
  ATMOSPHERIC MEASUREMENT TECHNIQUES, 6, 9, 2311, 2338, 2013, [Peer-reviewed]
  English, Scientific journal
• Impact of a new temperature-dependence correction on historical meisei radiosonde humidity data
  Takuji Sugidachi; Masatomo Fujiwara
  Scientific Online Letters on the Atmosphere, 9, 1, 179, 182, 2013, [Peer-reviewed]
  English, Scientific journal
• Cold trap dehydration in the Tropical Tropopause Layer characterised by SOWER chilled-mirror hygrometer network data in the Tropical Pacific
  F. Hasebe; Y. Inai; M. Shiotani; M. Fujiwara; H. Voemel; N. Nishi; S. -Y. Ogino; T. Shibata; S. Iwasaki; N. Komala; T. Peter; S. J. Oltmans
  ATMOSPHERIC CHEMISTRY AND PHYSICS, 13, 8, 4393, 4411, 2013, [Peer-reviewed]
  English, Scientific journal
• On the use of the correction factor with Japanese ozonesonde data
  G. A. Morris; G. Labow; H. Akimoto; M. Takigawa; M. Fujiwara; F. Hasebe; J. Hirokawa; T. Koide
  ATMOSPHERIC CHEMISTRY AND PHYSICS, 13, 3, 1243, 1260, 2013, [Peer-reviewed]
  English, Scientific journal
• Dehydration in the tropical tropopause layer estimated from the water vapor match
  Y. Inai; F. Hasebe; M. Fujiwara; M. Shiotani; N. Nishi; S. Y. Ogino; H. Vömel; S. Iwasaki; T. Shibata
  Atmospheric Chemistry and Physics, 13, 17, 8623, 8642, Copernicus {GmbH}, 2013, [Peer-reviewed]
  English, Scientific journal
• Southern Hemisphere Additional Ozonesondes (SHADOZ) ozone climatology (2005-2009): Tropospheric and tropical tropopause layer (TTL) profiles with comparisons to OMI-based ozone products
  Anne M. Thompson; Sonya K. Miller; Simone Tilmes; Debra W. Kollonige; Jacquelyn C. Witte; Samuel J. Oltmans; Bryan J. Johnson; Masatomo Fujiwara; F. J. Schmidlin; G. J. R. Coetzee; Ninong Komala; Matakite Maata; Maznorizan Bt Mohamad; J. Nguyo; C. Mutai; S-Y. Ogino; F. Raimundo Da Silva; N. M. Paes Leme; Francoise Posny; Rinus Scheele; Henry B. Selkirk; Masato Shiotani; Rene Stuebi; Gilbert Levrat; Bertrand Calpini; Valerie Thouret; Haruo Tsuruta; Jessica Valverde Canossa; Holger Voemel; S. Yonemura; Jorge Andres Diaz; Nguyen T. Tan Thanh; Hoang T. Thuy Ha
  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 117, Dec. 2012, [Peer-reviewed]
  English, Scientific journal
• High supersaturation inside cirrus in well-developed tropical tropopause layer over Indonesia
  Y. Inai; T. Shibata; M. Fujiwara; F. Hasebe; H. Voemel
  GEOPHYSICAL RESEARCH LETTERS, 39, Oct. 2012, [Peer-reviewed]
  English, Scientific journal
• Analysis of the tropical tropopause layer using the Nonhydrostatic Icosahedral Atmospheric Model (NICAM): 2. An experiment under the atmospheric conditions of December 2006 to January 2007
  H. Kubokawa; M. Fujiwara; T. Nasuno; M. Miura; M. K. Yamamoto; M. Satoh
  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 117, Sep. 2012, [Peer-reviewed]
  English, Scientific journal
• Diurnal tides from the troposphere to the lower mesosphere as deduced from TIMED/SABER satellite data and six global reanalysis data sets
  T. Sakazaki; M. Fujiwara; X. Zhang; M. E. Hagan; J. M. Forbes
  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 117, Jul. 2012, [Peer-reviewed]
  English, Scientific journal
• Wave activity in the tropical tropopause layer in seven reanalysis and four chemistry climate model data sets
  M. Fujiwara; J. Suzuki; A. Gettelman; M. I. Hegglin; H. Akiyoshi; K. Shibata
  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 117, Jun. 2012, [Peer-reviewed]
  English, Scientific journal
• Cirrus cloud appearance in a volcanic aerosol layer around the tropical cold point tropopause over Biak, Indonesia, in January 2011
  T. Shibata; M. Hayashi; A. Naganuma; N. Hara; K. Hara; F. Hasebe; K. Shimizu; N. Komala; Y. Inai; H. Voemel; S. Hamdi; S. Iwasaki; M. Fujiwara; M. Shiotani; S-Y. Ogino; N. Nishi
  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 117, Jun. 2012, [Peer-reviewed]
  English, Scientific journal
• Southern Hemisphere Additional Ozonesondes (SHADOZ) ozone climatology (2005-2009): Tropospheric and tropical tropopause layer (TTL) profiles with comparisons to OMI-based ozone products
  Anne M. Thompson; Sonya K. Miller; Simone Tilmes; Debra W. Kollonige; Jacquelyn C. Witte; Samuel J. Oltmans; Bryan J. Johnson; Masatomo Fujiwara; F. J. Schmidlin; G. J.R. Coetzee; Ninong Komala; Matakite Maata; Maznorizan Bt Mohamad; J. Nguyo; C. Mutai; S. Y. Ogino; F. Raimundo Da Silva; N. M. Paes Leme; Francoise Posny; Rinus Scheele; Henry B. Selkirk; Masato Shiotani; René Stbi; Gilbert Levrat; Bertrand Calpini; Valérie Thouret; Haruo Tsuruta; Jessica Valverde Canossa; Holger Vmel; S. Yonemura; Jorge Andrés Diaz; Nguyen T. Tan Thanh; Hoang T. Thuy Ha
  Journal of Geophysical Research Atmospheres, 117, 23, Blackwell Publishing Ltd, 2012, [Peer-reviewed]
  English, Scientific journal
• Diurnal variations of upper tropospheric and lower stratospheric winds over Japan as revealed with middle and upper atmosphere radar (34.85 degrees N, 136.10 degrees E) and five reanalysis data sets
  T. Sakazaki; M. Fujiwara; H. Hashiguchi
  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 115, Dec. 2010, [Peer-reviewed]
  English, Scientific journal
• Multimodel assessment of the upper troposphere and lower stratosphere: Tropics and global trends
  A. Gettelman; M. I. Hegglin; S. -W. Son; J. Kim; M. Fujiwara; T. Birner; S. Kremser; M. Rex; J. A. Anel; H. Akiyoshi; J. Austin; S. Bekki; P. Braesike; C. Bruehl; N. Butchart; M. Chipperfield; M. Dameris; S. Dhomse; H. Garny; S. C. Hardiman; P. Joeckel; D. E. Kinnison; J. F. Lamarque; E. Mancini; M. Marchand; M. Michou; O. Morgenstern; S. Pawson; G. Pitari; D. Plummer; J. A. Pyle; E. Rozanov; J. Scinocca; T. G. Shepherd; K. Shibata; D. Smale; H. Teyssedre; W. Tian
  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 115, Oct. 2010, [Peer-reviewed]
  English, Scientific journal
• Seasonal to decadal variations of water vapor in the tropical lower stratosphere observed with balloon-borne cryogenic frost point hygrometers
  M. Fujiwara; H. Voemel; F. Hasebe; M. Shiotani; S-Y. Ogino; S. Iwasaki; N. Nishi; T. Shibata; K. Shimizu; E. Nishimoto; J. M. Valverde Canossa; H. B. Selkirk; S. J. Oltmans
  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 115, Sep. 2010, [Peer-reviewed]
  English, Scientific journal
• Diurnal Variations in Lower-Tropospheric Wind over Japan Part II: Analysis of Japan Meteorological Agency Mesoscale Analysis Data and Four Global Reanalysis Data Sets
  Takatoshi Sakazaki; Masatomo Fujiwara
  JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN, 88, 3, 349, 372, Jun. 2010, [Peer-reviewed]
  English, Scientific journal
• Diurnal Variations in Lower-Tropospheric Wind over Japan Part I: Observational Results using the Wind Profiler Network and Data Acquisition System (WINDAS)
  Takatoshi Sakazaki; Masatomo Fujiwara
  JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN, 88, 3, 325, 347, Jun. 2010, [Peer-reviewed]
  English, Scientific journal
• Analysis of the tropical tropopause layer using the Nonhydrostatic Icosahedral Atmospheric Model (NICAM): Aqua planet experiments
  H. Kubokawa; M. Fujiwara; T. Nasuno; M. Satoh
  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 115, Apr. 2010, [Peer-reviewed]
  English, Scientific journal
• Analysis of the tropical tropopause layer using the Nonhydrostatic Icosahedral Atmospheric Model (NICAM): Aqua planet experiments
  H. Kubokawa; M. Fujiwara; T. Nasuno; M. Satoh
  Journal of Geophysical Research Atmospheres, 115, 8, Blackwell Publishing Ltd, 2010, [Peer-reviewed]
  English, Scientific journal
• Cloud-Top Height Variability Associated with Equatorial Kelvin Waves in the Tropical Tropopause Layer during the Mirai Indian Ocean cruise for the Study of the MJO-Convection Onset (MISMO) Campaign
  Junko Suzuki; Masatomo Fujiwara; Atsushi Hamada; Yoichi Inai; Jun Yamaguchi; Ryuichi Shirooka; Fumio Hasebe; Toshiaki Takano
  SOLA, 6, 97, 100, 2010, [Peer-reviewed]
  English, Scientific journal
• Cirrus observations in the tropical tropopause layer over the western Pacific
  M. Fujiwara; S. Iwasaki; A. Shimizu; Y. Inai; M. Shiotani; F. Hasebe; I. Matsui; N. Sugimoto; H. Okamoto; N. Nishi; A. Hamada; T. Sakazaki; K. Yoneyama
  Journal of Geophysical Research Atmospheres, 114, 9, D09304, Blackwell Publishing Ltd, 16 May 2009, [Peer-reviewed]
  English, Scientific journal
• Cirrus observations in the tropical tropopause layer over the western Pacific
  M. Fujiwara; S. Iwasaki; A. Shimizu; Y. Inai; M. Shiotani; F. Hasebe; I. Matsui; N. Sugimoto; H. Okamoto; N. Nishi; A. Hamada; T. Sakazaki; K. Yoneyama
  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 114, May 2009, [Peer-reviewed]
  English, Scientific journal
• Correction of Radiosonde Pressure and Temperature Measurements Using Simultaneous GPS Height Data
  Yoichi Inai; Fumio Hasebe; Kensaku Shimizu; Masatomo Fujiwara
  SOLA, 5, 109, 112, 2009, [Peer-reviewed]
  English, Scientific journal
• Diurnal Variations in Summertime Surface Wind upon Japanese Plains: Hodograph Rotation and Its Dynamics
  Takatoshi Sakazaki; Masatomo Fujiwara
  JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN, 86, 5, 787, 803, Oct. 2008, [Peer-reviewed]
  English, Scientific journal
• Ozonesonde observations at Christmas Island (2*N, 157*W) in the equatorial central pacific
  Hisahiro Takashima; M. Shiotani; M. Fujiwara; N. Nishi; F. Hasebe
  Journal of Geophysical Research Atmospheres, 113, 10, Blackwell Publishing Ltd, 27 May 2008, [Peer-reviewed]
  English, Scientific journal
• Correlation between equatorial Kelvin waves and the occurrence of extremely thin ice clouds at the tropical tropopause
  F. Immler; K. Krueger; M. Fujiwara; G. Verver; M. Rex; O. Schrems
  ATMOSPHERIC CHEMISTRY AND PHYSICS, 8, 14, 4019, 4026, 2008, [Peer-reviewed]
  English, Scientific journal
• Correction for Radiation Dry Bias Found in RS92 Radiosonde Data during the MISMO Field Experiment
  Kunio Yoneyama; Mikiko Fujita; Naoki Sato; Masatomo Fujiwara; Yoichi Inai; Fumio Hasebe
  SOLA, 4, 13, 16, 2008, [Peer-reviewed]
  English, Scientific journal
• Validation of Aura Microwave Limb Sounder water vapor by balloon-borne Cryogenic Frost point Hygrometer measurements
  Holger Vömel; J. E. Barnes; R. N. Forno; M. Fujiwara; F. Hasebe; S. Iwasaki; R. Kivi; N. Komala; E. Kyrö; T. Leblanc; B. Morel; S. Y. Ogino; W. G. Read; S. C. Ryan; S. Saraspriya; H. Selkirk; M. Shiotani; J. Valverde Canossa; D. N. Whiteman
  Journal of Geophysical Research Atmospheres, 112, 24, Blackwell Publishing Ltd, 27 Dec. 2007, [Peer-reviewed]
  English, Scientific journal
• Validation of Aura Microwave Limb Sounder Ozone by ozonesonde and lidar measurements
  Y. B. Jiang; L. Froidevaux; A. Lambert; N. J. Livesey; W. G. Read; J. W. Waters; B. Bojkov; T. Leblanc; I. S. McDermid; S. Godin-Beekmann; M. J. Filipiak; R. S. Harwood; R. A. Fuller; W. H. Daffer; B. J. Drouin; R. E. Cofield; D. T. Cuddy; R. F. Jarnot; B. W. Knosp; V. S. Perun; M. J. Schwartz; W. V. Snyder; P. C. Stek; R. P. Thurstans; P. A. Wagner; M. Allaart; S. B. Andersen; G. Bodeker; B. Calpini; H. Claude; G. Coetzee; J. Davies; H. De Backer; H. Dier; M. Fujiwara; B. Johnson; H. Kelder; N. P. Leme; G. König-Langlo; E. Kyro; G. Laneve; L. S. Fook; J. Merrill; G. Morris; M. Newchurch; S. Oltmans; M. C. Parrondos; F. Posny; F. Schmidlin; P. Skrivankova; R. Stubi; D. Tarasick; A. Thompson; V. Thouret; P. Viatte; H. Vömel; P. von Der Gathen; M. Yela; G. Zablocki
  Journal of Geophysical Research Atmospheres, 112, 24, Blackwell Publishing Ltd, 27 Dec. 2007, [Peer-reviewed]
  English, Scientific journal
• A trajectory-based estimate of the tropospheric ozone column using the residual method
  M. R. Schoeberl; J. R. Ziemke; B. Bojkov; N. Livesey; B. Duncan; S. Strahan; L. Froidevaux; S. Kulawik; P. K. Bhartia; S. Chandra; P. F. Levelt; J. C. Witte; A. M. Thompson; E. Cuevas; A. Redondas; D. W. Tarasick; J. Davies; G. Bodeker; G. Hansen; B. J. Johnson; S. J. Oltmans; H. Vömel; M. Allaart; H. Kelder; M. Newchurch; S. Godin-Beekmann; G. Ancellet; H. Claude; S. B. Andersen; E. Kyrö; M. Parrondos; M. Yela; G. Zablocki; D. Moore; H. Dier; P. von der Gathen; P. Viatte; R. Stübi; B. Calpini; P. Skrivankova; V. Dorokhov; H. de Backer; F. J. Schmidlin; G. Coetzee; M. Fujiwara; V. Thouret; F. Posny; G. Morris; J. Merrill; C. P. Leong; G. Koenig-Langlo; E. Joseph
  Journal of Geophysical Research Atmospheres, 112, 24, Blackwell Publishing Ltd, 27 Dec. 2007, [Peer-reviewed]
  English, Scientific journal
• Origin and transport of tropical cirrus clouds observed over Paramaribo, Suriname (5.8°N, 55.2°W)
  J. P.F. Fortuin; C. R. Becker; M. Fujiwara; F. Immler; H. M. Kelder; M. P. Scheele; O. Schrems; G. H.L. Verver
  Journal of Geophysical Research Atmospheres, 112, 9, Blackwell Publishing Ltd, 16 May 2007, [Peer-reviewed]
  English, Scientific journal
• Cirrus clouds, humidity, and dehydration in the tropical tropopause layer observed at Paramaribo, Suriname (5.8°N, 55.2°W)
  Franz Immler; Kirstin Krüger; Susann Tegtmeier; Masatomo Fujiwara; Paul Fortuin; Gé Verver; Otto Schrems
  Journal of Geophysical Research Atmospheres, 112, 3, Blackwell Publishing Ltd, 16 Feb. 2007, [Peer-reviewed]
  English, Scientific journal
• Tropical cirrus clouds near cold point tropopause under ice supersaturated conditions observed by lidar and ballon-borne cryogenic frost point hygrometer
  Takashi Shibata; Holger Vömel; Saipul Hamdi; Sri Kaloka; Fumio Hasebe; Masatomo Fujiwara; Masato Shiotani
  Journal of Geophysical Research Atmospheres, 112, 3, Blackwell Publishing Ltd, 16 Feb. 2007, [Peer-reviewed]
  English, Scientific journal
• In situ observations of dehydrated air parcels advected horizontally in the Tropical Tropopause Layer of the western Pacific
  F. Hasebe; M. Fujiwara; N. Nishi; M. Shiotani; H. Voemel; S. Oltmans; H. Takashima; S. Saraspriya; N. Komala; Y. Inai
  ATMOSPHERIC CHEMISTRY AND PHYSICS, 7, 803, 813, Feb. 2007, [Peer-reviewed]
  English, Scientific journal
• Performance of the Vaisala RS80A/H and RS90 humicap sensors and the meteolabor "Snow white" chilled-mirror hygrometer in Paramaribo, Suriname
  Ge Verver; Masatomo Fujiwara; Pier Dolmans; Cor Becker; Paul Fortuin; Larry Miloshevich
  JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY, 23, 11, 1506, 1518, Nov. 2006, [Peer-reviewed]
  English, Scientific journal
• Combined MU radar and ozonesonde measurements of turbulence and ozone fluxes in the tropo-stratosphere over Shigaraki, Japan
  NM Gavrilov; S Fukao; H Hashiguchi; K Kita; K Sato; Y Tomikawa; M Fujiwara
  GEOPHYSICAL RESEARCH LETTERS, 33, 9, May 2006, [Peer-reviewed]
  English, Scientific journal
• Correlations and emission ratios among bromoform, dibromochloromethane, and dibromomethane in the atmosphere
  Y. Yokouchi; F. Hasebe; M. Fujiwara; H. Takashima; M. Shiotani; N. Nishi; Y. Kanaya; S. Hashimoto; P. Fraser; D. Toom-Sauntry; H. Mukai; Y. Nojiri
  Journal of Geophysical Research Atmospheres, 110, 23, 1, 9, Blackwell Publishing Ltd, 16 Dec. 2005, [Peer-reviewed]
  English, Scientific journal
• New Characteristics of the Tropical Tropopause Revealed by CHAMP/GPS Measurements
  M. Venkat Ratnam; T. Tsuda; M. Shiotani; M. Fujiwara
  SOLA, 1, 185, 188, 2005, [Peer-reviewed]
  English, Scientific journal
• Radiation balance of the tropical tropopause layer
  A Gettelman; PMD Forster; M Fujiwara; Q Fu; H Vomel; LK Gohar; C Johanson; M Ammerman
  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 109, D7, Apr. 2004, [Peer-reviewed]
  English, Scientific journal
• Upper-tropospheric inversion and easterly jet in the tropics
  M Fujiwara; SP Xie; M Shiotani; H Hashizume; F Hasebe; H Vomel; SJ Oltmans; T Watanabe
  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 108, D24, Dec. 2003, [Peer-reviewed]
  English, Scientific journal
• The behavior of the Snow White chilled-mirror hygrometer in extremely dry conditions
  H Vomel; M Fujiwara; M Shiotani; F Hasebe; SJ Oltmans; JE Barnes
  JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY, 20, 11, 1560, 1567, Nov. 2003, [Peer-reviewed]
  English, Scientific journal
• Performance of the meteolabor ''Snow White'' chilled-mirror hygrometer in the tropical troposphere: Comparisons with the Vaisala RS80 A/H-Humicap sensors
  M Fujiwara; M Shiotani; F Hasebe; H Vomel; SJ Oltmans; PW Ruppert; T Horinouchi; T Tsuda
  JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY, 20, 11, 1534, 1542, Nov. 2003, [Peer-reviewed]
  English, Scientific journal
• Kelvin-Helmholtz instability around the tropical tropopause observed with the Equatorial Atmosphere Radar
  MK Yamamoto; M Fujiwara; T Horinouchi; H Hashiguchi; S Fukao
  GEOPHYSICAL RESEARCH LETTERS, 30, 9, May 2003, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Turbulence at the tropopause due to breaking Kelvin waves observed by the Equatorial Atmosphere Radar
  M Fujiwara; MK Yamamoto; H Hashiguchi; T Horinouchi; S Fukao
  GEOPHYSICAL RESEARCH LETTERS, 30, 4, Feb. 2003, [Peer-reviewed]
  English, Scientific journal
• Reply to comment by A. E. Dessler and E. M. Weinstock on "Balloon-borne observations of water vapor and ozone in the tropical upper troposphere and lower stratosphere" by H. Vomel et al.
  H Vomel; SJ Oltmans; BJ Johnson; F Hasebe; M Shiotani; M Fujiwara; N Nishi; M Agama; J Cornejo; F Paredes; Enriquez, II
  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 108, D4, Feb. 2003, [Peer-reviewed]
  English
• Southern Hemisphere Additional Ozonesondes (SHADOZ) 1998-2000 tropical ozone climatology - 2. Tropospheric variability and the zonal wave-one
  AM Thompson; JC Witte; SJ Oltmans; FJ Schmidlin; JA Logan; M Fujiwara; VWJH Kirchhoff; F Posny; GJR Coetzee; B Hoegger; SJ Kawakami; T Ogawa; JPF Fortuin; HM Kelder
  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 108, D2, Jan. 2003, [Peer-reviewed]
  English, Scientific journal
• Southern Hemisphere Additional Ozonesondes (SHADOZ) 1998-2000 tropical ozone climatology - 1. Comparison with Total Ozone Mapping Spectrometer (TOMS) and ground-based measurements
  AM Thompson; JC Witte; RD McPeters; SJ Oltmans; FJ Schmidlin; JA Logan; M Fujiwara; VWJH Kirchhoff; F Posny; GJR Coetzee; B Hoegger; S Kawakami; T Ogawa; BJ Johnson; H Vomel; G Labow
  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 108, D2, Jan. 2003, [Peer-reviewed]
  English, Scientific journal
• Ozonesonde observations in the Indonesian maritime continent: a case study on ozone rich layer in the equatorial upper troposphere
  M Fujiwara; Y Tomikawa; K Kita; Y Kondo; N Komala; S Saraspriya; T Manik; A Suripto; S Kawakami; T Ogawa; E Kelana; B Suhardi; SWB Harijono; M Kudsy; T Sribimawati; MD Yamanaka
  ATMOSPHERIC ENVIRONMENT, 37, 3, 353, 362, Jan. 2003, [Peer-reviewed]
  English, Scientific journal
• Direct observations of atmospheric boundary layer response to SST variations associated with tropical instability waves over the eastern equatorial Pacific
  H Hashizume; SP Xie; M Fujiwara; M Shiotani; T Watanabe; Y Tanimoto; WT Liu; K Takeuchi
  JOURNAL OF CLIMATE, 15, 23, 3379, 3393, Dec. 2002, [Peer-reviewed]
  English, Scientific journal
• Ozonesonde observations in the equatorial eastern Pacific - the Shoyo-Maru survey
  M Shiotani; M Fujiwara; F Hasebe; H Hashizume; H Vomel; SJ Oltmans; T Watanabe
  JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN, 80, 4B, 897, 909, Sep. 2002, [Peer-reviewed]
  English, Scientific journal
• Balloon-borne observations of water vapor and ozone in the tropical upper troposphere and lower stratosphere
  H Vomel; SJ Oltmans; BJ Johnson; F Hasebe; M Shiotani; M Fujiwara; N Nishi; M Agama; J Cornejo; F Paredes; H Enriquez
  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 107, D14, Jul. 2002, [Peer-reviewed]
  English, Scientific journal
• Relationship between wind and precipitation observed with a UHF radar, GPS rawinsondes and surface meteorological instruments at Kototabang, West Sumatera during September-October 1998
  F Murata; MD Yamanaka; M Fujiwara; SY Ogino; H Hashiguchi; S Fukao; M Kudsy; T Sribiawati; SWB Harijono; E Kelana
  JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN, 80, 3, 347, 360, Jun. 2002, [Peer-reviewed]
  English, Scientific journal
• Formation of an ozone lamina due to differential advection revealed by intensive observations
  Y Tomikawa; K Sato; K Kita; M Fujiwara; M Yamamori; T Sano
  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 107, D10, May 2002, [Peer-reviewed]
  English, Scientific journal
• Role of the equatorial Kelvin wave in stratosphere-troposphere exchange in a general circulation model
  M Fujiwara; M Takahashi
  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 106, D19, 22763, 22780, Oct. 2001, [Peer-reviewed]
  English, Scientific journal
• Water vapor control at the tropopause by equatorial Kelvin waves observed over the Galapagos
  M Fujiwara; F Hasebe; M Shiotani; N Nishi; H Vomel; SJ Oltmans
  GEOPHYSICAL RESEARCH LETTERS, 28, 16, 3143, 3146, Aug. 2001, [Peer-reviewed]
  English, Scientific journal
• Tropical tropospheric ozone and biomass burning
  AM Thompson; JC Witte; RD Hudson; H Guo; Herman, JR; M Fujiwara
  SCIENCE, 291, 5511, 2128, 2132, Mar. 2001, [Peer-reviewed]
  English, Scientific journal
• Seasonal variation of tropospheric ozone in Indonesia revealed by 5-year ground-based observations
  Masatomo Fujiwara; Kazuyuki Kita; Toshihiro Ogawa; Shuji Kawakami; Takuki Sano; Ninong Komala; Slamet Saraspriya; Agus Suripto
  Journal of Geophysical Research Atmospheres, 105, 2, 1879, 1888, Blackwell Publishing Ltd, 2000, [Peer-reviewed]
  English, Scientific journal
• Ozonesonde observations in Indonesia during the BIBLE-A period
  M. Fujiwara; K. Kita; S. Kawakami; T. Ogawa; S. Saraspriya; T. Manik; A. Suripto; N. Komala; E. Kelana; T. Sribimawati; M. Kudsy; S. W; B. Harijono; M. D. Yamanaka
  Proceedings of Quadrennial Ozone Symposium Sapporo 2000, 389-390, 2000
  English, International conference proceedings
• Ozone-increased layers in the free troposphere observed over Indonesia and Northern Australia in BIBLE-A and B aircraft observation campaigns
  Y. Higashi; K. Kita; Y. Miyazaki; Y. Tomikawa; M. Fujiwara; S. Kawakami; T. Shirai; N. Nishi; Y. Kondo; D. Blake; B. Liley; N. Komala; S. Saraspriya; A. Suripto; M. Timbul; T. Ogawa
  Proceedings of the Quadrennial ozone symposium Sapporo 2000, 427-428, 2000
  English, International conference proceedings
• Observation and origin of dry sir with high mixing ratios of ozone and its precursor gases in the tropical and subtropical upper troposphere during BIBLE aircraft observations
  S. Kawakami; K. Kita; Y. Miyazaki; Y. Higashi; M. Fujiwara; Y. Tomikawa; N. Nishi; Y. Kondo; D. Blake; B. Liley; N. Komala; S. Saraspriya; A. Suripto; A. Shirai; T. Ogawa
  Proceedings of Quadrennial Ozone Symposium Sapporo 2000, 95-96, 2000
  English, International conference proceedings, Proceedings of Quadrennial Ozone Symposium Sapporo 2000
• Total ozone increase associated with forest fires over the Indonesian region and its relation to the El Nino-Southern oscillation
  K Kita; M Fujiwara; S Kawakami
  ATMOSPHERIC ENVIRONMENT, 34, 17, 2681, 2690, 2000, [Peer-reviewed]
  English, Scientific journal
• Seasonal variation of tropospheric ozone in Indonesia revealed by 5-year ground-based observations
  M Fujiwara; K Kita; T Ogawa; S Kawakami; T Sano; N Komala; S Saraspriya; A Suripto
  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 105, D2, 1879, 1888, Jan. 2000, [Peer-reviewed]
  English, Scientific journal
• Tropospheric ozone enhancements during the Indonesian forest fire events in 1994 and in 1997 as revealed by ground-based observations
  M Fujiwara; K Kita; S Kawakami; T Ogawa; N Komala; S Saraspriya; A Suripto
  GEOPHYSICAL RESEARCH LETTERS, 26, 16, 2417, 2420, Aug. 1999, [Peer-reviewed]
  English, Scientific journal
• Stratosphere-troposphere exchange of ozone associated with the equatorial Kelvin wave as observed with ozonesondes and rawinsondes
  M Fujiwara; K Kita; T Ogawa
  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 103, D15, 19173, 19182, Aug. 1998, [Peer-reviewed]
  English, Scientific journal
• Tropospheric ozone over Pacific and Indonesian Region: Relation with ENSO activity and a preliminary report on BIBLE aircraft campaign
  K. Kita; M. Fujiwara; Y. Miyazaki; S. Kawakami; T. Ogawa; N. Komala; S. Saraspriya; Y. Kondo; M. Koike; T. Machida; B. Liley; D. Blake; M. Watanabe; N. Nishi
  Proceedings of International symposium on tropospheric ozone in East Asia and its potential impacts on vegetation, 45-46, 1998
  English, International conference proceedings

• 第6回WCRP再解析国際会議報告
  古林慎哉; 中村尚; 隈健一; 田中泰宙; 直江寛明; 藤原正智; 池内光希; 大野木和敏; 髙坂裕貴; 小林ちあき; 関澤偲温; 原田やよい; 福井真; 藤井陽介; 山崎哲, 天気, 73, 2, 69, 77, Feb. 2026, [Domestic magazines]
  日本気象学会, Japanese, Meeting report
• Chapter 4: Hunga effects on stratospheric temperatures and circulation
  X. Wang; L. Coy; M. Fujiwara; P. Lin; A. Ming; F. Li; E. M. Bednarz; Z. Zhuo; K. Krüger, The Hunga Volcanic Eruption Atmospheric Impacts Report, edited by Y. Zhu, G. Mann, P. A. Newman, and W. Randel, APARC Report No. 11, WCRP-10/2025, 89, 106, Dec. 2025, ［Internationally co-authored］, [International Magazine]
  Atmospheric Processes And their Role in Climate, English, Introduction scientific journal
• Results of the NPB2-6 Balloon Flight Performance Test (B25-04 Experiment) and Future Prospects
  SAITO, Yoshitaka; FUKE, Hideyuki; IIJIMA, Issei; IKEDA, Chusaku; IKUTA, Ayumu; KAWASHIMA, Fumihiro; KOKUBUN, Motohide; MIZUMURA, Yoshitaka; YAMADA, Kazuhiko; YAMANE, Fumiya; HARADA, Masatomo; AKITA, Daisuke; AWAKI, Hisamitsu; FUJIWARA, Masatomo; ISHIMURA, Kosei; KAHO, Takana; TERASAKA, Kaito; KAWAKAMI, Rina; SETO, Haruto; MORI, Hideyuki; NAGASHIMA, Kana; TAMURA, Makoto; UENO, Sota; MATSUO, Takuma; MIZUKOSHI, Keita; NAKASHINO, Kyoichi; OKAZAKI, Tomoya; SAWANO, Tatsuya; TOGASHI, Takumi; TOMIKAWA, Yoshihiro; YAMADA, Noboru; HASHIMOTO, Hiroyuki; IGARASHI, Yutaka; MATSUSHIMA, Kiyoho, Balloon Symposium: 2025, Oct. 2025
  著者名の誤記: Mori Hieyukii
  著者名の誤記: Naghashima Kana
  レポート番号: isas25-sbs-011, 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS), Japanese
• 7.2 人工衛星による大気観測
  藤原正智, 成層圏・対流圏を巡る大気, 気象研究ノート, 第250号, 154 pp. （長谷部文雄, 青木周司, 柴田隆, 編）, 119, 125, Aug. 2025, [Lead author], [Domestic magazines]
  日本気象学会, Japanese, Introduction scientific journal
• Toward Future Reanalyses That Meet Evolving Needs in Science, Public Services, Policymaking, and Socioeconomic Activity
  Hisashi Nakamura; Shinya Kobayashi; Maureen Anyango Wanzala; Fanny Adloff; Lijing Cheng; Alison Cobb; Dick Dee; Amal El Akkraoui; Masatomo Fujiwara; Hans Hersbach; Hiroaki Naoe; S. Indira Rani; Nick Rayner; Adrian Simmons; Laura Slivinski; Taichu Tanaka; Peter Thorne; Chunxue Yang; Yonghong Yin; Akeem Shola Ayinde; Abhirup Banerjee; Michael G. Bosilovich; Leunell Chris Medrano Buela; Bo Dong; Shin Fukui; Nariaki Hirose; Hiroki Ikeuchi; Nir Krakauer; Andre Lenouo; Bimochan Niraula; Charikleia L. G. Oikonomou; Shion Sekizawa; Nischal Sharma; Akira Yamazaki; Takuma Yoshida, Bulletin of the American Meteorological Society, 106, 7, E1445, E1453, Jul. 2025, ［Internationally co-authored］, [International Magazine]
  American Meteorological Society
• 日本の中層大気研究の現状と展望
  河谷芳雄; 佐藤薫; 堀之内武; 江口菜穂; 木下武也; 高麗正史; 小林ちあき; 坂崎貴俊; 原田やよい; 藤原正智; 渡辺真吾; 秋吉英治; 稲飯洋一; 奥井晴香; 黒田友二; 小新大; 小玉知央; 小寺邦彦; 菅原敏; 田口正和; 直江寛明; 中村哲; 野口峻佑; 廣岡俊彦; 町田敏暢; 宮崎和幸; 三好勉信; 向川均; 安井良輔; 山下陽介; 吉田康平; 余田成男, 天気, 72, 211, 239, 2025, [Domestic magazines]
• 国際オゾンシンポジウム2024報告
  中島英彰; 村田功; YANG Tianliang; 関谷高志; 藤原正智; 上里至; 宮川幸治, Tenki, 72, 113, 120, Jan. 2025, [Domestic magazines]
  Meteorological Society of Japan, Japanese, Meeting report
• 2-Day Early-Career Scientists' Event at the A-RIP 2024 Planning Workshop in Boulder
  M. A. Diallo; S. M. Davis; V. L. Harvey; J. S. Wrigh; G. L. Manney; M. Fujiwara; K. Wargan, APARC Newsletter, 64, 26, 28, Jan. 2025, ［Internationally co-authored］, [International Magazine]
  APARC, English, Meeting report
• A-RIP Update and Planning Workshop Report
  J. S. Wrigh; G. L. Manney; K. Wargan; B. Monge-Sanz; M. Fujiwara; M. Diallo; V. L. Harvey; S. M. Davis, APARC Newsletter, 64, 13, 25, Jan. 2025, ［Internationally co-authored］, [International Magazine]
  APARC, English, Meeting report
• Report on the 2nd International Conference on the Asian Summer Monsoon Anticyclone (ASMA-2023)
  S. K. Mehta; M. Fujiwara; S. Tegtmeier; S. Fadnavis; M. V. Ratnam; K. K. Kumar; S. S. Das; S. K. Sharma; R. V. Nair; V. Velu; C. Sarangi; N. Ojha; L. K. Sahu; A. Kottyail; Sabin T. P.; M. Gogoi; K. Mohankumar; M. N. Rajeevan, APARC Newsletter, 64, 10, 12, Jan. 2025, ［Internationally co-authored］, [International Magazine]
  APARC, English, Meeting report
• 1.16 上下結合（日本の気象学の現状と展望2024, 日本気象学会第42期学術委員会編, 27-90）
  藤原正智; 田口正和; 中村哲; 江口菜穂, Tenki, 72, 45, 46, Jan. 2025, [Lead author], [Domestic magazines]
  Meteorological Society of Japan, Japanese, Introduction scientific journal
• 1.9 中層大気（日本の気象学の現状と展望2024, 日本気象学会第42期学術委員会編, 27-90）
  河谷芳雄; 佐藤薫; 江口菜穂; 木下武也; 高麗正史; 小林ちあき; 坂崎貴俊; 原田やよい; 藤原正智; 堀之内武; 渡辺真吾, Tenki, 72, 37, 38, Jan. 2025, [Domestic magazines]
  Meteorological Society of Japan, Japanese, Introduction scientific journal
• 南極における大気重力波のスーパープレッシャー気球観測計画（LODEWAVE）の第2回キャンペーン観測の結果
  冨川, 喜弘; 佐藤, 薫; 斎藤, 芳隆; 村田, 功; 平沢, 尚彦; 高麗, 正史; 中篠, 恭一; 秋田, 大輔; 松尾, 卓摩; 藤原, 正智; 加保, 貴奈; 吉田, 理人; 川上, 莉奈, 大気球シンポジウム: 2024年度, Oct. 2024
  レポート番号: isas24-sbs-032, 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS), Japanese
• Preliminary results of LODEWAVE Phase II
  冨川喜弘; 冨川喜弘; 斎藤芳隆; 村田功; 佐藤薫; 平沢尚彦; 高麗正史; 中篠恭一; 秋田大輔; 松尾卓摩; 藤原正智; 加保貴奈; 吉田理人; 川上莉奈, 地球電磁気・地球惑星圏学会総会及び講演会(Web), 156th, 2024
• Verification test of the quasi-static balloon launch method using winch with NPB2-4a balloon
  SAITO, Yoshitaka; IIJIMA, Issei; IKEDA, Chusaku; IKUTA, Ayumu; MORI, Hideyuki; MIZUKOSHI, Keita; MIZUMURA, Yoshitaka; TAMURA, Makoto; YAMATANI, Masahiro; YAMADA, Kazuhiko; AKITA, Daisuke; NAKASHINO, Kyoichi; MATSUO, Takuma; ISHIMURA, Kosei; YAMADA, Noboru; KAHO, Takana; FUJIWARA, Masatomo; IGARASHI, Yutaka; HASHIMOTO, Hiroyuki; MATSUSHIMA, Kiyoho, Balloon Symposium: 2023, 01 Oct. 2023
  レポート番号: isas23-sbs-024, 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS), Japanese
• Current Challenges and Future Directions in Data Assimilation and Reanalysis
  Arianna Valmassoi; Jan D. Keller; Daryl T. Kleist; Stephen English; Bodo Ahrens; Ivan Bašták Ďurán; Elisabeth Bauernschubert; Michael G. Bosilovich; Masatomo Fujiwara; Hans Hersbach; Lili Lei; Ulrich Löhnert; Nabir Mamnun; Cory R. Martin; Andrew Moore; Deborah Niermann; Juan José Ruiz; Leonhard Scheck, Bulletin of the American Meteorological Society, 104, 4, E756, E767, Apr. 2023, [International Magazine]
  American Meteorological Society, English, Meeting report
• Planning and proposal for phase 2 of the SPARC-Reanalysis Intercomparison Project (S-RIP)
  Wright, J; G. Manney; M. Fujiwara, SPARC Newsletter, 60, 12, 16, 2023, ［Internationally co-authored］, [International Magazine]
  English, Introduction scientific journal
• オゾン観測ネットワークの現状～札幌と那覇サイトの停止を受けて～
  林田佐智子; 中島英彰; 藤原正智; 山内恭; 金谷有剛; 笠井康子; 今村隆史, 天気, 70, 19, 25, 2023, [Domestic magazines]
  Japanese, Introduction scientific journal
• NPB2-4気球を用いた凖静的な立上げによる新しい放球方法の検証—Verification of a new quasi-static launching method using NPB2-4 balloon
  斎藤, 芳隆; 水村, 好貴; 山田, 和彦; 秋田, 大輔; 石村, 康生; 加保, 貴奈; 藤原, 正智; 中篠, 恭一; 古田, 竜也; 松尾, 卓摩; 山田, 昇; 五十嵐, 優; 橋本, 紘幸; 松嶋, 清穂; SAITO, Yoshitaka; MIZUMURA, Yoshitaka; YAMADA, Kazuhiko; AKITA, Daisuke; ISHIMURA, Kosei; KAHO, Takana; FUJIWARA, Masatomo; NAKASHINO, Kyoichi; FURUTA, Tatsuya; MATSUO, Takuma; YAMADA, Noboru; IGARASHI, Yutaka; HASHIMOTO, Hiroyuki; MATSUSHIMA, Kiyoho, 大気球シンポジウム: 2022年度 = Balloon Symposium: 2022, Nov. 2022
  大気球シンポジウム 2022年度（2022年11月7-8日. ハイブリッド開催（JAXA相模原キャンパス& オンライン))
  Balloon Symposium 2022 (November 7-8, 2022. Hybrid(in-person & online) Conference (Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan
  著者人数: 14名
  資料番号: SA6000177027
  レポート番号: isas22-sbs-027, 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS), Japanese
• Cloud observations
  Fujiwara, M; A. Reale; B. Sun; X. Calbet; M. Maturilli; B. Demoz; R. K. Sakai; D. Lam; D. Edwards; F. Madonna; D. Cimini; J.-C. Dupont; M. Iwabuchi; R. Kivi; F. Carminati; T. Gardiner; M. Sommer; T. Simeonov; J. Wang; P. Thorne, GRUAN Report No. 5, Jun. 2022, [Lead author, Corresponding author], ［Internationally co-authored］, [International Magazine]
  This document discusses and summarises two separate topics regarding cloud observations to be collected at the Global Climate Observing System (GCOS) Reference Upper-Air Network (GRUAN) sites: (i) recommendations for reporting the existing cloud observations at GRUAN sites (primarily to help identify "clear" scenes for satellite sensor validation), and (ii) initial recommendations for generating cloud-related GRUAN data products, keeping in mind the GCOS cloud-related Essential Climate Variables (ECVs)., GRUAN Lead Centre, English, Introduction other
• 本だな 「高層気象台100年誌（高層気象台彙報特別号）」高層気象台編
  藤原正智, 天気, 69, 176, 177, Mar. 2022, [Domestic magazines]
  日本気象学会, Japanese, Book review
• 令和３年度（2021 年度）オゾン層等の監視結果に関する年次報告書
  環境省, 2022
• S-RIP Final Report Published
  Fujiwara, M; G. L. Manney; L. J. Gray; J. S. Wright, SPARC Newsletter, 58, 12, 13, Jan. 2022, [Lead author], ［Internationally co-authored］, [International Magazine]
  English, Book review
• Quadrennial Ozone Symposium 2021 in Seoul, South Korea
  Petropavlovskikh, I; J.-H. Koo; S. Godin-Beekmann; P. Newman; A. Pazmino; A. Klekociuk; B. Hassler; C. Vigouroux; D. Kinnison; G. Lee; J. Tamminen; J. Gröbner; K. Walker; K. Kreher; K. Jucks; L. Pan; L. Zhang; M. Weber; M. Fujiwara; M. Tully; N. Livesey; S. S. Park; S.-W. Son; S. Reis; S. Montzka; S. Park; U. Langematz; V. Thouret; W. Steinbrecht; Y. Kanaya, SPARC Newsletter, 58, 26, 33, Jan. 2022, ［Internationally co-authored］, [International Magazine]
  English, Meeting report
• 南極における大気重力波のスーパープレッシャー気球観測計画(LODEWAVE)の現況２
  冨川 喜弘; 佐藤 薫; 斎藤 芳隆; 村田 功; 平沢 尚彦; 高麗 正史; 中篠 恭一; 秋田 大輔; 松尾 卓摩; 藤原 正智; 吉田 理人; TOMIKAWA Yoshihiro; SATO Kaoru; SAITO Yoshitaka; MURATA Isao; HIRAZAWA Naohiko; KOHRA Masashi; NAKASHINO Kyoichi; AKITA Daisuke; MATSUO Takuma; FUJIWARA Masatomo; YOSHIDA Lihito, 大気球シンポジウム: 2021年度 = Balloon Symposium: 2021, Nov. 2021
  大気球シンポジウム 2021年度（2021年11月1-2日. オンライン開催)著者人数: 11名資料番号: SA6000166033レポート番号: isas21-sbs-033, 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS), Japanese
• LODEWAVE (LOng-Duration balloon Experiment of gravity WAVE over Antarctica)
  斎藤芳隆; 冨川喜弘; 村田功; 加保貴奈; 菅野高司, 電子情報通信学会技術研究報告(Web), JAXA-RR-20-009, 128(SAT2021 20-26), 19, 33, Feb. 2021, [Peer-reviewed], [Domestic magazines]
  Atmospheric gravity waves transport momentum in the atmosphere and play an important role in determining temperature and material distribution through driving the meridional circulation in the middle atmosphere. However, they have wide spatial and temporal scales, which make it difficult to capture the whole feature of gravity waves with any of the latest observations and models. The first Mesosphere-Stratosphere-Troposphere (MST)/ Incoherent Scatter (IS) radar in the Antarctic, PANSY, which was installed at Syowa Station in 2011, can directly estimate the momentum flux of gravity waves in all frequency bands by observing 3-dimensional winds with high precision and high resolution. On the other hand, the super pressure (SP) balloon observation can also estimate momentum transport due to gravity waves in all frequency bands, and its horizontal distribution is also clarified. In order to carry out this SP balloon observation in the Antarctic where the observational constraint on the momentum transport due to gravity waves is especially insufficient, we proposed the LOng-Duration balloon Experiment of gravity WAVE over Antarctica (LODEWAVE). By combining it with the PANSY observation and the state-of-the-art meteorological reanalysis data, the 3-dimensional picture of momentum transport due to gravity waves is acquired, which contributes to the improvement of the future prediction by the climate model. We have performed a test production of SP balloon and onboard instruments during FY 2019. The further development and test of the SP balloon and onboard instruments will be carried out in FY 2020. In the first half of FY 2021, a domestic balloon experiment will be carried out at Taiki Aerospace Research Field in Hokkaido. In the latter half of FY 2021, a maximum of 3 SP balloon observations will be carried out at Syowa Station in the Antarctic. By developing the SP balloon and onboard instruments which are light and small enough to ease the restrictions of the Civil Aeronautics Act, we aim to establish a regular observation system in the Antarctic., Japan Aerospace Exploration Agency (JAXA), Japanese, Technical report
• アジアモンスーンに伴う中緯度から熱帯へのオゾン輸送の季節内変動による変調
  荻野慎也; 鈴木順子; 木下武也; 藤原正智; 城岡竜一, 日本気象学会大会講演予稿集(CD-ROM), 119, 2021
• 令和２年度（2020 年度）オゾン層等の監視結果に関する年次報告書
  環境省, 2021
  Others
• International conference on the Asian summer monsoon anticyclone: Gateway of surface pollutants to the stratosphere
  Mehta, S. K; M. Fujiwara; S. Tegtmeier; M. V. Ratnam; S. Fadnavis; M. Santee; H. Schlager, SPARC Newsletter, 55, 21, 25, Jul. 2020
  English, Meeting report
• 成層圏対流圏過程とその気候における役割（SPARC）第6回総会報告
  佐藤薫; 塩谷雅人; 余田茂男; 堀之内武; 菅原敏; 藤原正智; 秋吉英治; 渡辺真吾; 冨川喜弘; 河谷芳雄; 小林ちあき; 田口正和; 江口菜穂; 宮崎和幸; 坂崎貴俊; 高麗正史; 木下武也, 天気, 67, 5, 285, 293, Jun. 2020
  Japanese, Meeting report
• Singapore upper air station visited by SPARC researchers
  Fujiwara, M; S.-L. Wong; L. Choo; G. Bodeker; P. A. Newman; L. Coy; J. A. Anstey; M. Kunze; U. Langematz, SPARC Newsletter, 54, 42, 47, Jan. 2020, [Lead author]
  English, Introduction other
• オゾンに関する観測的研究の将来展望：2018年秋季オゾン研究連絡会の報告
  林田佐智子; 竹内綾子; 金谷有剛; 高島久洋; 藤原正智; 宮崎和幸; 笠井康子, 天気, 66, 6, 457, 461, 2019
  日本気象学会, Japanese, Meeting report
• Review of multiple-payload radiosonde sounding configurations for determining best-practice guidance for GRUAN sites
  Jauhiainen, H; M. Fujiwara; R. Philipona; R. Dirksen; D. F. Hurst; R. Kivi; H. Vömel; B. Demoz; N. Kizu; T. Oakley; K. Shimizu; M. Maturilli; T. Leblanc; F. Madonna; R. Querel, GRUAN-TD-7, 2019
  English
• S-RIP activities in 2018
  Fujiwara, M; G. Manney; L. Gray; J. Wright; S. Davis, SPARC Newsletter, 52, 19, 20, 2019
  English, Meeting report
• Advancing Global and Regional Reanalyses
  Buizza, R; P. Poli; M. Rixen; M. Alonso-Balmaseda; M. G. Bosilovich; S. Brönnimann; G. P. Compo; D. P. Dee; F. Desiato; M. Doutriaux-Boucher; M. Fujiwara; A. K. Kaiser-Weiss; S. Kobayashi; Z. Liu; S. Masina; P.-P. Mathieu; N. Rayner; C. Richter; S. I. Seneviratne; A. J. Simmons; J.-N. Thépaut; J. D. Auger; M. Bechtold; E. Berntell; B. Dong; M. Kozubek; K. Sharif; C. Thomas; S. Schimanke; A. Storto; M. Tuma; I. Välisuo; A. Vaselali, Bulletin of the American Meteorological Society, 99, 8, ES139, ES144, 2018
  English, Meeting report
• 第5回再解析国際会議報告
  古林慎哉; 原田昌; 小林ちあき; 原田やよい; 大島和裕; 中村尚; 福井真; 藤原正智; 山崎哲; 芳村圭, 天気, 65, 431, 439, 2018
  Japanese, Introduction scientific journal
• Technical characteristics and GRUAN data processing for the Meisei RS-11G and iMS-100 radiosondes
  Kizu, N; T. Sugidachi; E. Kobayashi; S. Hoshino; K. Shimizu; R. Maeda; M. Fujiwara, GRUAN-TD-5, 2018
  English, Introduction other
• The 2017 S-RIP workshop and the 13th SPARC data assimilation workshop
  McCormack, J; M. Fujiwara; Q. Errera; L. Gray; G. Manney; B. Monge-Sanz; R. Dragani, SPARC Newsletter, 50, 26, 29, 2018
  English, Meeting report
• 山岳が熱帯対流圏界面近傍の気温変動に与える影響に関する研究
  久保川陽呂鎮; 佐藤正樹; 佐藤正樹; 鈴木順子; 藤原正智, 日本気象学会大会講演予稿集, 111, 2017
• Measuring Clouds with Balloons
  藤原正智; 林真由美; 杉立卓治, 計測と制御 (計測自動制御学会), 56, 5, 348, 354, 2017, [Invited]
  計測自動制御学会 ; 1962-, Japanese, Introduction scientific journal
• The 12th SPARC Data Assimilation Workshop and 2016 S-RIP Workshop
  Fujiwara, M; Q. Errera; L. J. Gray; G. L. Manney; J. McCormack; J. Anstey, SPARC Newsletter, 48, 41, 44, 2017
  English, Meeting report
• The 2015 S-RIP workshop and 11th SPARC data assimilation workshop
  Errera, Q; M. Fujiwara; B. Legras, SPARC Newsletter, 47, 12, 19, 2016
  English, Meeting report
• Public perception of climate engineering in Japan: Results from online and classroom surveys
  Sugiyama, M; M. Fujiwara, Policy Alternatives Research Institute, the University of Tokyo, Working Paper series, PARI-WP No. 23, 2016
  English, Report research institution
• A368 西太平洋の上部対流圈にみられる赤道ケルビン波の経年変動性(熱帯大気・台風II,一般口頭発表)
  鈴木 順子; 西 憲敬; 藤原 正智; 米山 邦夫, 大会講演予講集, 108, 499, 499, 2015
  日本気象学会, Japanese
• C155 複数の再解析データを用いた赤道域成層圏東西風の比較と検証(中層大気,一般口頭発表)
  河谷 芳雄; Hamilton Kevin; 宮崎 和幸; 藤原 正智; Anstey James, 大会講演予講集, 108, 147, 147, 2015
  日本気象学会, Japanese
• Report from the 10th SPARC data assimilation workshop and the 2014 SPARC Reanalysis Intercomparison Project (S-RIP) workshop in Washington DC, USA
  Errera, Q; M. Fujiwara; C. Long; D. Jackson, SPARC Newsletter, 44, 31, 38, 2015
  English, Meeting report
• 対流圏界面観測用超小型タンデム気球の開発
  斎藤芳隆; 山田和彦; 藤原正智, 大気圏シンポジウム・講演集(Web), 28th, 2014
• Chapter 2: Update on Global Ozone: Past, Present, and Future
  S. Pawson; W. Steinbrecht; A.J. Charlton-Perez; M. Fujiwara; A.Yu. Karpechko; I. Petropavlovskikh; J. Urban; M. Weber, Scientific Assessment of Ozone Depletion: 2014, World Meteorological Organization, Global Ozone Research and Monitoring Project – Report No. 55, 2014
  English, Introduction other
• 第2章 ラジオゾンデ観測 2.3. ゴム気球搭載用水蒸気計
  杉立卓治; 藤原正智, 気象研究ノート, 229, 高層気象観測の発展と現状 （水野量, 上窪哲郎, 定村努, 編）, 229, 47, 72, 2014
  Japanese, Report scientific journal
• CINDY2011観測期間中にみられた熱帯インド洋対流圏界面遷移層における短周期擾乱による巻雲変動
  鈴木順子; 城岡竜一; 米山邦夫; 勝俣昌己; 藤原正智; 西澤智明; 松井一郎; 杉本伸夫, ブルーアース要旨集, 2013, 2013
• D351 SMILSとオゾンゾンデ観測のオゾンプロファイルの比較検証 : オゾンゾンデに起因する問題点についての考察(中層大気,口頭発表)
  塩谷 雅人; 今井 弘二; 稲飯 洋一; 藤原 正智; 長谷部 文雄; 眞子 直弘; 鈴木 睦; 佐野 琢己; 光田 千紘; 内藤 陽子; 小出 孝, 大会講演予講集, 104, 571, 571, 2013
  日本気象学会, Japanese
• SPARC Reanalysis Intercomparison Project (S-RIP) Planning Meeting, 29 April-1 May, 2013, Exeter, UK
  Fujiwara, M; D. Jackson, SPARC Newsletter, 41, 52, 55, 2013
  English, Introduction scientific journal
• GCOS Reference Upper Air Network (GRUAN): Steps Towards Assuring Future Climate Records
  P. W. Thorne; H. Voemel; G. Bodeker; M. Sommer; A. Apituley; F. Berger; S. Bojinski; G. Braathen; B. Calpini; B. Demoz; H. J. Diamond; J. Dykema; A. Fasso; M. Fujiwara; T. Gardiner; D. Hurst; T. Leblanc; F. Madonna; A. Merlone; A. Mikalsen; C. D. Miller; T. Reale; K. Rannat; C. Richter; D. J. Seidel; M. Shiotani; D. Sisterson; D. G. H. Tan; R. S. Vose; J. Voyles; J. Wang; D. N. Whiteman; S. Williams, TEMPERATURE: ITS MEASUREMENT AND CONTROL IN SCIENCE AND INDUSTRY, VOL 8, 1552, 1042, 1047, 2013
  English, Introduction international proceedings
• GRUAN Radiosonde Task Team Review Report on the 2010 WMO Radiosonde Intercomparison
  Miloshevich, L; M. Fujiwara; R. Philipona; the Radiosonde; Task Team, GRUAN Report 2, GRUAN Lead Centre, GRUAN-RP-2, Rev. 1.0, 2012
  English, Introduction other
• A proposal of the SPARC Reanalysis/Analysis Intercomparison Project
  Fujiwara, M; S. Polavarapu; D. Jackson, SPARC Newsletter, 38, 14, 17, 2012
  English, Introduction scientific journal
• 気候工学（ジオエンジニアリング）の紹介
  藤原 正智, 大気化学研究会ニュースレター, 26, 7, 8, 2012
  Japanese, Introduction scientific journal
• P219 西太平洋熱帯対流圏界層における水蒸気と巻雲(ポスター・セッション)
  稲飯 洋一; 柴田 隆; 藤原 正智; 長谷部 文雄; Vomel Holger, 大会講演予講集, 99, 336, 336, 2011
  日本気象学会, Japanese
• C159 WINDASで明らかになった日本上空下部対流圏の風の日変動(WPRの高度利用について,ウィンドプロファイラの現状と将来,専門分科会)
  坂崎 貴俊; 藤原 正智, 大会講演予講集, 99, 173, 173, 2011
  日本気象学会, Japanese
• D205 TIMED/SABERデータおよび全球再解析データを用いた対流圏-下部中間圏の大気潮汐の研究(大気力学,一般口頭発表)
  坂崎 貴俊; 藤原 正智; Hagan Maura; Zhang Xiaoli; Forbes Jeffrey, 大会講演予講集, 99, 244, 244, 2011
  日本気象学会, Japanese
• B354 気球CO_2ゾンデの開発とCO_2高度分布計測(スペシャル・セッション「大気中の二酸化炭素観測手法の新たな展開とそのデータ利用」,一般口頭発表)
  大内 麻衣; 笹子 宏史; 松見 豊; 中山 智喜; 藤原 正智; 清水 健作; 柴田 耕志; 塩谷 雅人; 井上 元; 今須 良一; 横田 達也, 大会講演予講集, 100, 174, 174, 2011
  日本気象学会, Japanese
• A New Upper-Air Sounding Network for Climate Monitoring, GRUAN
  FUJIWARA Masatomo, 天気, 58, 8, 679, 695, 2011
  日本気象学会, Japanese, Introduction scientific journal
• Climate Geoengineering
  SUGIYAMA Masahiro; NISHIOKA Jun; FUJIWARA Masatomo, 天気, 58, 7, 577, 598, 2011
  Climate geoengineering is defined as "deliberate large-scale manipulation of the planetary environment to counteract anthropogenic climate change." The slow progress of greenhouse gas emissions reduction and a heightened recognition of the risk of dangerous global warming have led to increasing attention to this novel approach, although it cannot substitute for mitigation nor adaptation. The IPCC will review geoengineering as part of its fifth assessment report. There are two main categories of climate engineering options: carbon dioxide removal (CDR), which reduces the concentration of the atmospheric carbon dioxide, a primary cause of global warming; and solar radiation management (SRM) that reduces the incoming solar radiation, thereby cooling the earth system. An example of the CDR approach is to add iron to the ocean to increase photosynthesis. Amongst many proposed approaches, the most promising is arguably the stratospheric aerosol injection, an SRM option. Its physics is similar to that of global cooling following volcanic eruptions. Research has shown that it would be accompanied with undesired effects such as changes in precipitation patterns. The GeoMIP, an international effort to climate model intercomparison on this approach, has recently been launched. Though intended as a cure of global warming, climate geoengineering confronts the human society with a number of problems. It would require an international framework since, if conducted unilaterally, it would affect the global climate as a whole. In the short run, guidelines for experiments in the natural environment would be crucial, on which international discussions just commenced., 日本気象学会, Japanese, Introduction scientific journal
• 北大は新入生を歓迎する(先生からのメッセージ)
  藤原 正智, リテラポプリ, 44, 12, 12, 2011, [Invited]
  Japanese, Others
• D408 WINDASで明らかになった日本上空下部対流圏の風の日変動(大気力学,一般口頭発表)
  坂崎 貴俊; 藤原 正智, 大会講演予講集, 97, 212, 212, 2010
  日本気象学会, Japanese
• C111 熱帯対流圏界面付近にみられる赤道ケルビン波活動度のENSO依存性(中層大気,口頭発表)
  鈴木 順子; 西 憲敬; 藤原 正智; 城岡 竜一, 大会講演予講集, 98, 196, 196, 2010
  日本気象学会, Japanese
• P130 全球再解析データを用いた対流圏 : 下部中間圏の大気潮汐の研究(ポスター・セッション)
  坂崎 貴俊; 藤原 正智; Haean Maura; Zhang Xiaoli; Forbes Jeffrey, 大会講演予講集, 98, 367, 367, 2010
  日本気象学会, Japanese
• らせんのひとめぐり (小特集号「大気化学研究のさらなる発展へ向けて」)
  藤原 正智, 大気化学研究会ニュースレター, 23, 9, 10, 2010, [Invited]
  Japanese, Introduction scientific journal
• Chapter 7. Upper Troposphere and Lower Stratosphere (UTLS)
  A. Gettelman; M. Hegglin; S.-W. Son; M. Fujiwara; S. Tilmes; L. Pan; P. Hoor; H. Lee; G. Manney; T. Birner; G. Stiller; M. Rex; S. Kremser; D. Wuebbles; K. Walker; J. A. Añel, SPARC CCMVal Report on the Evaluation of Chemistry-Climate Models, V. Eyring, T. G. Shepherd, and D. W. Waugh (Eds.), SPARC Report No. 5, 2010
  English, Introduction other
• C367 全球・非静力学大気モデルNICAMの2006年12月MJO実験データを用いた対流圏界面領域の解析(1)(熱帯大気)
  久保川 陽呂鎮; 藤原 正智; 那須野 智江; 佐藤 正樹, 大会講演予講集, 96, 249, 249, 2009
  日本気象学会, Japanese
• P341 MISMO期間のインド洋上空にみられる赤道ケルビン波が背景場に与える影響
  鈴木 順子; 米山 邦夫; 藤原 正智; 清水 厚; 稲飯 洋一; 城岡 竜一; 吉崎 正憲; 長谷部 文雄; 松井 一郎; 杉本 伸夫, 大会講演予講集, 95, 362, 362, 2009
  日本気象学会, Japanese
• P404 GPS高度データの利用によるラジオゾンデ気圧気温データの補正
  稲飯 洋一; 長谷部 文雄; 清水 健作; 藤原 正智; Vomel Holger, 大会講演予講集, 95, 367, 367, 2009
  日本気象学会, Japanese
• P127 ベトナム・ハノイにおける下部対流圏逆転層と広域循環との関係
  荻野 慎也; 野津 雅人; 立花 義裕; 藤原 正智; 里村 雄彦; 松本 淳; Thanh Nguyen Thi Tan, 大会講演予講集, 94, 374, 374, 2008
  日本気象学会, Japanese
• B106 ベトナム・ハノイにおけるオゾン変動(微量気体・GOSAT)
  荻野 慎也; 藤原 正智; 塩谷 雅人; 長谷部 文雄; Hoang Thuy Ha; Thanh Nguyen Thi Tan, 大会講演予講集, 94, 114, 114, 2008
  日本気象学会, Japanese
• P304 WINDAS・MUレーダーを用いた下層大気の風の日変動の解析
  坂崎 貴俊; 藤原 正智; 橋口 浩之, 大会講演予講集, 94, 449, 449, 2008
  日本気象学会, Japanese
• P313 キリバスにおけるに熱帯圏界面付近の雲の頻度分布
  岩崎 杉紀; 松井 一郎; 塩谷 雅人; 藤原 正智; 長谷部 文雄; 清水 厚; 杉本 伸夫, 大会講演予講集, 93, 424, 424, 2008
  日本気象学会, Japanese
• P216 WINDASデータを用いた下部対流圏の風の日変動の解析
  坂崎 貴俊; 藤原 正智, 大会講演予講集, 93, 378, 378, 2008
  日本気象学会, Japanese
• P386 熱帯下部成層圏における水蒸気の長期変動(1)
  藤原 正智; 長谷部 文雄; 塩谷 雅人; Vomel H.; 荻野 慎也; 岩崎 杉紀; 西 憲敬; 柴田 隆; Oltmans S. J., 大会講演予講集, 94, 531, 531, 2008
  日本気象学会, Japanese
• 座談会 北大は地球温暖化に向き合う
  藤原正智; 西岡純; 堀口健夫; 間山貴文; 馬方; 松山聖央, リテラポプリ, 34, 6, 15, 2008
  Japanese, Others
• Round-table discussion. Hokkaido University faces up to global warming
  Fujiwara, M; J. Nishioka; T. Horiguchi; T. Mayama; F. Ma; M. Matsuyama, Littera Populi (English version), 34, 6, 15, 2008
  English, Others
• Introduction to SPARC
  林田 佐智子; 小寺 邦彦; 秋吉 英治; 今村 隆史; 岩崎 俊樹; 笠井 康子; 北 和之; 小池 真; 佐藤 薫; 塩谷 雅人; 柴田 清孝; 津田 敏隆; 廣岡 俊彦; 藤原 正智; 村山 泰啓; 余田 成男; 堤 雅基, 天気, 54, 11, 979, 982, 30 Nov. 2007
  日本気象学会, Japanese
• P330 キリバス、ビアックに設置したライダによるSubvisual Cirrus Cloudsの同時観測
  岩崎 杉紀; 松井 一郎; 清水 厚; 杉本 伸夫; 塩谷 雅人; 柴田 隆; 藤原 正智; 長谷部 文雄, 大会講演予講集, 91, 357, 357, 2007
  日本気象学会, Japanese
• D302 TTL水蒸気MATCHを用いた水平移流に伴う脱水の評価(中層大気)
  稲飯 洋一; 長谷部 文雄; 藤原 正智; 塩谷 雅人; 西 憲敬; 荻野 慎也; Voemel Holger, 大会講演予講集, 91, 208, 208, 2007
  日本気象学会, Japanese
• P311 インドネシア・ワトコセにおける対流圏オゾンの長期変化
  森岡 浩; 藤原 正智, 大会講演予講集, 92, 456, 456, 2007
  日本気象学会, Japanese
• P165 大気下層の風の日変動 : 海陸風・山谷風と大気潮汐の観点から
  坂崎 貴俊; 藤原 正智, 大会講演予講集, 92, 417, 417, 2007
  日本気象学会, Japanese
• P333 全球・非静力学大気モデルを用いた対流圏界面領域の解析(2)
  久保川 陽呂鎮; 藤原 正智; 那須野 智江; 佐藤 正樹, 大会講演予講集, 92, 478, 478, 2007
  日本気象学会, Japanese
• P346 熱帯西太平洋の対流圏界面領域におけるCirrusの観測
  藤原 正智; 岩崎 杉紀; 清水 厚; 塩谷 雅人; 松浦 弘和; 稲飯 洋一; 長谷部 文雄; 松井 一郎; 杉本 伸夫; 岡本 創; 西 憲敬; 濱田 篤; 米山 邦夫; Immler Franz, 大会講演予講集, 92, 491, 491, 2007
  日本気象学会, Japanese
• 成層圏対流圏結合
  藤原正智; 山崎孝治, 天気, 54, 597, 600, 2007, [Invited]
  Japanese, Introduction scientific journal
• P440 2004～2005年冬のベトナム・ハノイにおける対流圏下層の逆転層
  荻野 慎也; 立花 義裕; 藤原 正智; 里村 雄彦; 松本 淳; Thanh Nguyen Thi Tan, 大会講演予講集, 89, 466, 466, 2006
  日本気象学会, Japanese
• P164 ベトナム・ハノイにおける対流圏下層の逆転層 : 水蒸気と関係する季節内変動
  荻野 慎也; 野津 雅人; 立花 義裕; 藤原 正智; 里村 雄彦; 松本 淳; Thanh Nguyen Thi Tan, 大会講演予講集, 90, 322, 322, 2006
  日本気象学会, Japanese
• D107 熱帯中部太平洋クリスマス島における上部対流圏極低濃度オゾン(大気化学・物質輸送)
  高島 久洋; 塩谷 雅人; 藤原 正智; 西 憲敬; 長谷部 文雄, 大会講演予講集, 90, 208, 208, 2006
  日本気象学会, Japanese
• P376 全球・非静力学大気モデルを使用した対流圏界面領域の解析 : 水惑星実験の結果を用いて
  久保川 陽呂鎮; 藤原 正智; 那須野 智江; 佐藤 正樹, 大会講演予講集, 90, 424, 424, 2006
  日本気象学会, Japanese
• C158 ライダーと露点ゾンデによる熱帯圏界面層の巻雲および湿度の同時観測(物質循環II)
  柴田 隆; Hamdi Saipul; Kaloka Sri; Vomel Holger; 藤原 正智; 長谷部 文雄; 塩谷 雅人, 大会講演予講集, 88, 184, 184, 2005
  日本気象学会, Japanese
• Report of the 2nd International SOWER Meeting, San Cristobal, Galapagos, Ecuador, 10-15 July 2004
  Hasebe, F; M. Shiotani; M. Fujiwara; T.J. Dunkerton; I. Folkins; P. Fortuin; A. Gettelman; N.O. Hashiguchi; S. Iwasaki; Y. Kasai; N. Nishi; M. Niwano; S. Oltmans; L. Poveda; W, Randel; K. Rosenlof; Y. Tsushima; H. Voemel; K. Yamazaki, SPARC Newsletter, 24, 2005
  English, Meeting report
• C311 インドネシアにおける対流性降水雲に関する研究(第11報)(熱帯大気I)
  村田 文絵; 山中 大学; 荻野 慎也; 橋口 浩之; 藤原 正智; Sribimawati Tien; Kudsy Mahally; Harijono Sri Woro B.; Kelana Eddy, 大会講演予講集, 85, 137, 137, 2004
  日本気象学会, Japanese
• 鏡面冷却型水蒸気センサーを用いた熱帯対流圏界面領域における 水蒸気観測
  藤原 正智, 食生活科学・文化及び地球環境科学に関する研究助成, 研究紀要, 17, 165, 172, 2004
  Japanese, Introduction other
• P109 南米スリナムにおけるMeteolabor Snow White水蒸気計とVaisala RS90、RS80との同時比較観測
  藤原 正智; 塩谷 雅人; 長谷部 文雄; Verver G.; Kelder H. M.; Fortuin J. P. F.; Becker C. R.; Vomel H.; Oltmans S. J., 大会講演予講集, 84, 318, 318, 2003
  日本気象学会, Japanese
• P458 インドネシアにおける対流性降水雲に関する研究(第10報)
  村田 文絵; 荻野 慎也; 山中 大学; 藤原 正智; 深尾 昌一郎; 濱田 純一; 盛 修一; 森 修一; Sribimawati Tien; Kudsy Mahally; Harijono Sri Woro B.; Suhardi Budi; SUHARDI Budi, 大会講演予講集, 83, 500, 500, 2003
  日本気象学会, Japanese
• C303 赤道大気レーダーによる熱帯対流圏及び下部成層圏の波動解析(熱帯大気II)
  辻野 文剛; 山本 真之; 藤原 正智; 橋口 浩之; 山本 衛; 深尾 昌一郎, 大会講演予講集, 83, 162, 162, 2003
  日本気象学会, Japanese
• C304 赤道大気レーダーによる熱帯対流圏界面近傍の大気観測(熱帯大気II)
  山本 真之; 親松 昌幸; 堀之内 武; 藤原 正智; 橋口 浩之; 山本 衛; 深尾 昌一郎; 山中 大学; 山中 大学, 大会講演予講集, 83, 163, 163, 2003
  日本気象学会, Japanese
• B304 熱帯東太平洋において観測された上部対流圏逆転層と東風ジェット(熱帯大気)
  藤原 正智; 謝 尚平; 塩谷 雅人; 橋爪 寛; 長谷部 文雄; Vomel H.; Oltmans S. J.; 渡邊 朝生, 大会講演予講集, 84, 137, 137, 2003
  日本気象学会, Japanese
• EARによる対流圏界面領域の観測 : 赤道ケルビン波による乱流生成
  藤原 正智; 山本 真之; 橋口 浩之; 堀之内 武; 深尾 昌一郎, 大会講演予講集, 82, 309, 309, 09 Oct. 2002
  Japanese
• 赤道大気レーダーによる熱帯対流圏界面近傍のエコー観測
  親松 昌幸; 山本 真之; 橋口 浩之; 深尾 昌一郎; 堀之内 武; 藤原 正智; 山中 大学, 大会講演予講集, 82, 242, 242, 09 Oct. 2002
  Japanese
• 赤道大気レーダーで観測された熱帯対流圏界面直上のシアー不安定
  山本 真之; 橋口 浩之; 深尾 昌一郎; 堀之内 武; 藤原 正智; 山中 大学, 大会講演予講集, 82, 241, 241, 09 Oct. 2002
  Japanese
• インドネシアにおける対流性降水雲に関する研究(第9報)
  村田 文絵; 荻野 慎也; 山中 大学; 藤原 正智; 橋口 浩之; 深尾 昌一郎; 濱田 純一; 森 修一; TAUHID Yudi Iman; SRIBIMAWATI Tien; KUDSY Mahally; HARIJONO Sri Woro B.; SUHARDI Budi, 大会講演予講集, 82, 240, 240, 09 Oct. 2002
  Japanese
• 熱帯対流圏におけるMeteolabor SnowWhite露点計とVaisala Humicap-A/H相対湿度計との相互比較
  藤原 正智; 塩谷 雅人; 長谷部 文雄; VOMEL H.; OLTMANS S. J.; RUPPERT P., 大会講演予講集, 81, 442, 442, May 2002
  Japanese
• インドネシアにおける対流性降水雲に関する研究(第8報)
  村田 文絵; 荻野 慎也; 山中 大学; 藤原 正智; 橋口 浩之; 深尾 昌一郎; 濱田 純一; 森 修一; TAUHID Yudi Iman; SRIBIMAWATI Tien; KUDSY Mahally; HARIJONO Sri Woro B.; KELANA Eddy, 大会講演予講集, 81, 311, 311, May 2002
  Japanese
• 熱帯における成層圏対流圏大気交換過程 : 大規模擾乱の役割
  藤原 正智, 大会講演予講集, 81, 60, 60, May 2002
  Japanese
• Snow Whiteによる対流圏-下部成層圏領域の水蒸気観察,特定領域研究B成層圏力学過程とオゾンの変動およびその気候への影響
  藤原正智, 平成13年度公開シンポジウムプロシーディングス, 38, 43, 2002
• インドネシアにおける対流性降水雲に関する研究(第6報)
  村田 文絵; 荻野 慎也; 山中 大学; 藤原 正智; 橋口 浩之; 深尾 昌一郎; 濱田 純一; SRIBIMAWATI Tien; KUDSY Mahally; HARIJONO Sri Woro B.; KELANA Eddy, 大会講演予講集, 79, 281, 281, 08 May 2001
  Japanese
• 熱帯上部対流圏-対流圏界面における水蒸気ゾンデ観測(その2)
  藤原 正智; 塩谷 雅人; 長谷部 文雄; VOEMEL Holger; OLTMANS Samuel; RUPPERT Paul, 大会講演予講集, 79, 433, 433, 08 May 2001
  Japanese
• 19.札幌管区気象台訪問ツアー他(国際オゾンシンポジウム-Sapporo 2000-報告)
  藤原 正智, 天気, 48, 8, 573, 573, 2001
  Japanese
• Stratosphere-Tropsphere Exchange Associated with Equatorial Kelvin Waves and Researches on the Tropical Tropopause Region
  FUJIWARA Masatomo, 天気, 48, 11, 801, 810, 2001, [Invited]
  日本気象学会, Japanese, Introduction scientific journal
• 国際オゾンシンポジウム−Sapporo 2000−報告
  小川利紘; 小池真; 桑原徹也; 渡辺真吾; 河本望; 松川茂久; 宮崎雄三; 寺尾有希夫; 笠井康子; 長濱智生; 杉田考史; 須藤健吾; 香川亜紀子; 滝川雅之; 永島達也; 宮内正厚; 中島英彰; 入江仁士; 白井智子; 藤原正智; 柴崎和夫, 天気, 48, 8, 561, 576, 2001
  Japanese, Meeting report
• 熱帯上部対流圏-対流圏界面における水蒸気ゾンデ観測
  藤原 正智; 塩谷 雅人; 長谷部 文雄; VOEMEL Holger; OLTMANS Samuel; RUPPERT Paul, 大会講演予講集, 78, 245, 245, 18 Oct. 2000
  Japanese
• インドネシアにおける対流性降水雲に関する研究(第5報)
  村田 文絵; 荻野 慎也; 山中 大学; 藤原 正智; 大澤 輝夫; 橋口 浩之; 深尾 昌一郎; 濱田 純一; SRIBIMAWATI Tien; KUDSY Mahally; HARIJONO Sri Woro B.; KELANA Eddy, 大会講演予講集, 78, 314, 314, 18 Oct. 2000
  Japanese
• 中緯度下部成層圏オゾン層状構造の解析III
  冨川 喜弘; 藤原 正智; 北 和之; 佐藤 薫; 山森 美穂; 吉識 宗佳, 大会講演予講集, 77, 81, 81, 24 May 2000
  Japanese
• 高分解能大気大循環化学モデルによる物質輸送の研究
  高橋 正明; 秋吉 英治; 佐藤 薫; 藤原 正智; 滝川 雅之; 永島 達也; 須藤 健悟; 河谷 芳雄; 中元 美和, 大会講演予講集, 77, 75, 75, 24 May 2000
  Japanese
• インドネシア域でのバイオマス燃焼による対流圏オゾン増大現象とそのENSOに伴う変化 : 地上観測および航空機観測キャンペーンBIBLE-Aの結果より
  北 和之; 宮崎 雄三; 東 陽子; 藤原 正智; 近藤 豊; 小池 真; 竹田 真紀; 西 憲敬; BLAKE D.; KOMALA N; SARASPRIYA S; LILEY B.; 川上 修司; 佐野 琢己; 小川 利紘, 大会講演予講集, 77, 26, 26, 24 May 2000
  Japanese
• インドネシアにおける対流性降水雲に関する研究(第4報)
  村田 文絵; 山中 大学; 藤原 正智; 大澤 輝夫; 荻野 慎也; 橋口 浩之; 深尾 昌一郎; 濱田 純一; SRIBIMAWATI Tien; KUDSY Mahally; HARIJONO Sri Woro B., 大会講演予講集, 77, 198, 198, 24 May 2000
  Japanese
• 成層圏・対流圏大気交換における赤道波の役割(2)
  藤原 正智; 高橋 正明, 大会講演予講集, 77, 222, 222, 24 May 2000
  Japanese
• SOWER/Pacific 1998/99年集中観測 : 赤道対流圏界面領域における水蒸気濃度コントロール
  藤原 正智; 長谷部 文雄; 塩谷 雅人; 西 憲敬; VOEMEL Holger; OLTMANS Samuel, 大会講演予講集, 77, 142, 142, 24 May 2000
  Japanese
• SOWER/Pacific観測キャンペーンに参加して
  藤原正智; 庭野将徳, 天気, 47, 53, 56, 2000
  Japanese, Introduction scientific journal
• SOWER/Pacific - the Shoyo-maru Pacific Ocean-Atmospheric Survey
  Shiotani, M; M. Fujiwara; S. Xie; H. Hashizume; T. Saito; T. Watanabe; F. Hasebe, SPARC Newsletter, 14, 2000
  English, Meeting report
• インドネシアにおける対流性降水雲に関する研究(第3報)
  村田 文絵; 山中 大学; 藤原 正智; 大澤 輝夫; 荻野 慎也; 橋口 浩之; 濱田 純一; 深尾 昌一郎; SRIBIMAWATI Tien; KUDSY Mahally; HARIJONO Sri Woro B., 大会講演予講集, 76, 204, 204, 24 Nov. 1999
  Japanese
• SOWER/Pacific 1998/99 年集中観測 : 対流圏オゾンの変動
  塩谷 雅人; 長谷部 文雄; 豊田 賢二郎; 西 憲敬; 藤原 正智; 小川 利紘; VOEMEL H.; OLTMANS S.; GAGE K., 大会講演予講集, 76, 171, 171, 24 Nov. 1999
  Japanese
• SOWER/Pacific 1998/99 年集中観測 : 概要と初期の結果
  長谷部 文雄; 塩谷 雅人; VOMEL Holger; 藤原 正智; 西 憲敬; 庭野 将徳; 小川 利紘; OLTMANS Samuel; GAGE Kenneth, 大会講演予講集, 76, 170, 170, 24 Nov. 1999
  Japanese
• 中緯度下部成層圏オゾン層状構造の解析II
  冨川 喜弘; 藤原 正智; 北 和之; 佐藤 薫; 山森 美穂; 吉識 宗義, 大会講演予講集, 76, 261, 261, 24 Nov. 1999
  Japanese
• 成層圏・対流圏大気交換における赤道波の役割
  藤原 正智; 高橋 正明, 大会講演予講集, 76, 254, 254, 24 Nov. 1999
  Japanese
• オゾンゾンデ・ラジオゾンデ・MUレーダーによる集中同時観測 -下部成層圏オゾン層状構造と慣性重力波の解析-
  冨川 喜弘; 藤原 正智; 北 和之; 佐藤 薫; 山森 美穂; 吉識 宗佳, 大会講演予講集, 75, P282, Apr. 1999
  Japanese
• インドネシアにおける対流性降水雲に関する研究(第2報)
  村田 文絵; 山中 大学; 藤原 正智; 荻野 慎也; 橋口 浩之; 濱田 純一; 深尾 昌一郎; SRIBIMAWATI Tien; KUDSY Mahally; HARIJONO Sri Woro B, 大会講演予講集, 75, A202, Apr. 1999
  Japanese
• インドネシアにおける過去5年間のオゾン濃度変動
  藤原 正智; 北 和之; 川上 修司; 小川 利紘, 大会講演予講集, 73, 302, 302, May 1998
  Japanese
• トラジェクトリー解析によるインドネシア森林火災時のワトゥコセッ・オゾン高度分布の解析
  川上 修司; 藤原 正智; 北 和之; 小川 利紘, 大会講演予講集, 73, 301, 301, May 1998
  Japanese
• Photochemical Production of Tropospheric Ozone Due to the Indonesian Forest Fires
  FUJIWARA Masatomo; KITA Kazuyuki; KAWAKAMI Shuji; OGAWA Toshihiro, 火災, 48, 2, 25, 29, 20 Apr. 1998
  日本火災学会, Japanese
• 第10回中層大気会議の報告
  藤原 正智, 天気, 45, 379, 382, 1998
  Japanese, Introduction scientific journal
• インドネシア森林火災に伴う対流圏オゾン光化学生成
  藤原正智; 北和之; 川上修司; 小川利紘, 火災（日本火災学会誌）, 48, 45, 50, 1998, [Invited]
  Japanese, Introduction scientific journal
• Biomass burning in the tropics and tropospheric ozone
  Kita, K; M. Fujiwara; T. Ogawa, Global Environmental Research, 2, 29, 37, 1998
  English, Introduction other
• Total ozone enhancement in September and October 1994 in Indonesia
  Fujiwara, M; K. Kita; T. Ogawa; N. Komala; S. Saraspriya; A. Suripto; T. Sano, Atmospheric Ozone (Proceedings of the XVIII Quadrennial Ozone Symposium, L'Aquila, Italy, September 12-21, 1996), 1, 363, 366, 1998
  English, Introduction international proceedings
• TOMSデータから推定する対流圏オゾン変動
  北 和之; 佐藤 尚毅; 平田 康之; 藤原 正智; 小川 利絋; 佐野 琢己, 大会講演予講集, 71, 77, 77, May 1997
  Japanese
• 赤道波動に伴う成層圏対流圏大気交換過程
  藤原 正智; 北 和之; 小川 利絋, 大会講演予講集, 71, 89, 89, May 1997
  Japanese
• Tropospheric ozone increase in dry season of 1997 during forest fires in Indonesia
  KAWAKAMI Shuji; FUJIWARA Masatomo; KITA Kazuyuki; OGAWA Toshihiro, Journal of the Remote Sensing Society of Japan, 17, 5, 530, 535, 1997
  日本リモ-トセンシング学会, Japanese
• 熱帯域バイオマス燃焼と対流圏オゾン
  北和之; 藤原正智; 小川利紘, 地球環境, 2, 1, 33, 44, 1997
  国際環境研究協会, Japanese, Introduction other
• 熱帯上部対流圏におけるオゾン増大現象-成層圏大気の周期的な侵入?
  藤原 正智; 北 和之; 小川 利紘; 津田 敏隆; KOMALA Ninong; SARASPRIYA Slamet; 佐野 琢己; 前里 卓; 森山 隆, 大会講演予講集, 69, 170, 170, 21 May 1996
  Japanese
• 日本上空における一酸化炭素・オゾン濃度変動の航空機観測
  北 和之; 藤原 正智; 平田 康之; 小川 利紘; 矢澤 健司; 田丸 卓, 大会講演予講集, 69, 162, 162, 21 May 1996
  Japanese
• 地表境界層-自由対流圏間物質輸送の飛行船・航空機観測
  平田 康之; 北 和之; 藤原 正智; 小川 利紘; 佐野 琢己; 矢澤 健司; 田丸 卓, 大会講演予講集, 69, 264, 264, 21 May 1996
  Japanese
• インドネシアにおけるオゾン全量観測
  藤原 正智; 北 和之; 小川 利紘; KOMALA Ninong; SARASPRIYA Slamet; 前里 卓, 大会講演予講集, 67, 143, 143, 15 May 1995
  Japanese
• インドネシアにおけるオゾンゾンデ観測
  北 和之; 藤原 正智; 小川 利紘; KOMALA Ninong; SARASPRIYA Slamat; 前里 卓, 大会講演予講集, 67, 144, 144, 15 May 1995
  Japanese

• 成層圏・対流圏を巡る大気, 気象研究ノート, 第250号
  長谷部文雄; 青木周司; 柴田隆, 編, 7.2 人工衛星による大気観測
  日本気象学会, 2025, 154, Scholarly book, [Contributor]
• Field measurements for passive environmental remote sensing : instrumentation, intensive campaigns, and satellite applications
  Hurst, D. F; M. Fujiwara; S. Oltmans (Nalli, Nicholas R. ed.), Chapter 3. Frost point hygrometers
  Elsevier, 2022, 9780128239537, xv, 436 p., 18, English, ［Internationally co-authored］, [Peer-reviewed], [Joint work]
• SPARC Reanalysis Intercomparison Project (S-RIP) Final Report
  Masatomo Fujiwara; Gloria L. Manney; Lesley J. Gray; Jonathon S. Wright, Co-editor, Chapters 1, 2, 3, 4, 8, 9, 11, 12
  WRP/SPARC, Jan. 2022, 612, English, Scholarly book, [Peer-reviewed], [Joint editor]
• Handbook of Atmospheric Measurements
  Vömel, H; M. Fujiwara, Chapter 46. Aerological measurements
  edited by Thomas Foken, Springer Nature, Switzerland, 2021, 1247-1280, English, Scholarly book, ［Internationally co-authored］, [Peer-reviewed], [Joint work]
• 低温環境の科学事典
  河村公隆; 大島慶一郎; 小達恒夫; 川村賢二; 佐﨑元; 杉山慎; 関宰; 高橋晃周; 西岡純; 原登志彦; 福井学; 藤吉康志; 三寺史夫; 宮﨑雄三; 本山秀明; 渡部直樹, ブリューワー-ドブソン循環（成層圏の大気大循環）
  朝倉書店, 2016, [Contributor]
• 第2版 地球惑星科学入門
  在田一則; 竹下徹; 見延庄士郎; 渡部重十, 第18章共同執筆
  北海道大学出版会, 2015, [Contributor]
• 地球と宇宙の化学事典
  日本地球化学会, 成層圏大気の組成
  朝倉書店, 2012, [Contributor]
• 地球惑星科学入門
  在田一則; 竹下徹; 見延庄士郎; 渡部重十, 第18章共同執筆
  北海道大学出版会, 2010, [Contributor]
• オゾン層破壊の科学
  北海道大学大学院環境科, 序章, １章, ５-１章, ５-２章, 終章
  北海道大学出版会, 2007, 9784832981799, [Contributor]

• 南極における大気重力波のスーパープレッシャー気球観測計画(LODEWAVE)の現況
  冨川 喜弘; 佐藤 薫; 斎藤 芳隆; 村田 功; 平沢 尚彦; 高麗 正史; 中篠 恭一; 秋田 大輔; 松尾 卓摩; 藤原 正智; 吉田 理人; TOMIKAWA Yoshihiro; SATO Kaoru; SAITO Yoshitaka; MURATA Isao; HIRASAWA Naohiko; KOHMA Masashi; NAKASHINO Kyoichi; AKITA Daisuke; MATSUO Takuma; FUJIWARA Masatomo; YOSHIDA Rihito
  大気球シンポジウム: 2020年度 = Balloon Symposium: 2020, Nov. 2020, 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS), Japanese
  Nov. 2020 - Nov. 2020, 大気球シンポジウム 2020年度（2020年11月5-6日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)）, 相模原市, 神奈川県著者人数: 11名資料番号: SA6000151017レポート番号: isas20-sbs-017
• LODEWAVE (LOng-Duration balloon Experiment of gravity WAVE over Antarctica）
  Tomikawa Yoshihiro; Sato Kaoru; Saito Yoshitaka; Murata Isao; Hirasawa Naohiko; Kohma Masashi; Nakashino Kyoichi; Akita Daisuke; Matsuo Takuma; Fujiwara Masatomo; Yoshida Lihito
  大気球シンポジウム: 2019年度, Nov. 2019, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS), Japanese
  Nov. 2019 - Nov. 2019, Balloon Symposium 2019 (November 7-8, 2019. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS)), Sagamihara, Kanagawa Japan
• 可視では判別できないほど薄い雲が他の雲に与える影響
  岩崎杉紀; 岡本創; 佐藤可織; 片桐秀一郎; 藤原正智; 柴田隆; 坪木和久; 小野貴司; 杉立卓治
  日本気象学会大会講演予稿集, 30 Apr. 2018, Japanese
  30 Apr. 2018 - 30 Apr. 2018
• オゾンゾンデの応答時間に起因する系統誤差について
  塩谷雅人; 眞子直弘; 藤原正智; Herman G.J. Smit
  日本気象学会2017年度春季大会, 東京都, May 2017, Japanese
  May 2017 - May 2017
• CPS雲粒子ゾンデによって観測されたmixed―phase cloudの特徴
  岩崎杉紀; 藤原正智; 柴田隆; 坪木和久; 小野貴司; 杉立卓治
  日本気象学会大会講演予稿集, 30 Apr. 2017, Japanese
  30 Apr. 2017 - 30 Apr. 2017
• Development and a proposal of a test flight of the tiny tandem balloon system for tropopause observations
  Saito Yoshitaka; Yamada Kazuhiko; Fujiwara Masatomo; Yamada Noboru
  大気球シンポジウム: 平成28年度 = Balloon Symposium: 2016, Nov. 2016, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS), Japanese
  Nov. 2016 - Nov. 2016, Balloon Symposium 2016 (November 1-2, 2016. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan
• 対流圏界面観測用超小型タンデム気球の開発
  斎藤 芳隆; 山田 和彦; 藤原 正智; Saito Yoshitaka; Yamada Kazuhiko; Fujiwara Masatomo
  大気球シンポジウム: 平成27年度 = Balloon Symposium: 2015, Nov. 2015, 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS), Japanese
  Nov. 2015 - Nov. 2015, 大気球シンポジウム 平成27年度（2015年11月5-6日. 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS)）, 相模原市, 神奈川県資料番号: SA6000044027レポート番号: isas15-sbs-027
• B155 RS80ラジオゾンデ気圧バイアスに起因する高度誤差とその気象観測プロファイルへの影響(中層大気研究の最前線,専門分科会)
  稲飯 洋一; 塩谷 雅人; 藤原 正智; Voemel Holger; 長谷部 文雄
  大会講演予講集, 2015, 日本気象学会, Japanese
  2015 - 2015
• P242 ラジオゾンデ気圧バイアスに起因する高度計算誤差のオゾン・気温プロファイルへの影響(ポスターセッション)
  稲飯 洋一; 塩谷 雅人; 藤原 正智; 長谷部 文雄
  大会講演予講集, 2014, 日本気象学会, Japanese
  2014 - 2014
• SMILESとオゾンゾンデ観測のオゾンプロファイルの比較検証−オゾンゾンデに起因する問題点についての考察−
  塩谷雅人; 今井弘二; 稲飯洋一; 藤原正智; 長谷部文雄; 眞子直弘; 鈴木睦; 佐野琢己; 光田千紘; 内藤陽子; 小出孝
  日本気象学会2013年秋季大会, 仙台市, Nov. 2013, Japanese
  Nov. 2013 - Nov. 2013
• Diurnal wind variations in the upper-tropospheric and lower stratospheric wind over Japan as revealed with MU radar and five reanalysis data sets
  T. Sakazaki; M. Fujiwara; H. Hashiguchi
  The 13th Workshop on Technical and Scientific Aspects of MST/ST Radar, 19 Mar. 2012, English
  19 Mar. 2012 - 19 Mar. 2012
• B369 気候工学(ジオエンジニアリング)についての学部生を対象としたアンケート調査(生気象・気象教育,口頭発表)
  杉山 昌広; 藤原 正智
  大会講演予講集, 2012, 日本気象学会, Japanese
  2012 - 2012
• D370 Longitudinal dependence in the interannual variation of the temperature anomalies :
  Mehta Sanjay Kumar; Tsuda Toshitaka; Fujiwara Masatomo
  大会講演予講集, 2012, 日本気象学会, English
  2012 - 2012
• D211 成層圏残差循環における重力波の重要性 : 再解析データ比較プロジェクト(S-RIP)(中層大気,口頭発表)
  岡本 功太; 佐藤 薫; 藤原 正智
  大会講演予講集, 2012, 日本気象学会, Japanese
  2012 - 2012
• D201 SMILESオゾン観測データの他衛星データによる検証について(中層大気,口頭発表)
  今井 弘二; 塩谷 雅人; 佐野 琢己; 鈴木 睦; 眞子 直弘; 光田 千紘; 内藤 陽子; 坂崎 貴俊; 藤原 正智
  大会講演予講集, 2012, 日本気象学会, Japanese
  2012 - 2012
• B103 A possible bias of ozonesonde measurements owing to the response time problem :
  IMAI Koji; FUJIWARA Masatomo; SUZUKI Makoto; MANAGO Naohiro; SANO Takuki; MITSUDA Chihiro; NAITO Yoko; SHIOTANI Masato
  大会講演予講集, 2012, 日本気象学会, English
  2012 - 2012
• B168 熱帯インド洋の対流圏界面遷移層にみられた短周期擾乱による巻雲変動(スペシャル・セッション「インド洋におけるMJO研究-CINDY2011」,口頭発表)
  鈴木 順子; 藤原 正智; 西澤 智明; 松井 一郎; 城岡 竜一; 米山 邦夫; 勝俣 昌己; 杉本 伸夫
  大会講演予講集, 2012, 日本気象学会, Japanese
  2012 - 2012
• C155 SMILES観測で明らかになった中層大気オゾンの日変動(中層大気研究の新展開,専門分科会)
  坂崎 貴俊; 藤原 正智; 塩谷 雅人; 鈴木 睦; 秋吉 英治; Kinnison Doug
  大会講演予講集, 2012, 日本気象学会, Japanese
  2012 - 2012
• C151 熱帯対流圏界面における波活動 : 再解析7種と化学気候モデル4種の比較(中層大気研究の新展開,専門分科会)
  藤原 正智; 鈴木 順子; Gettelman Andrew; Hegglin Michaela I.; 秋吉 英治; 柴田 清孝
  大会講演予講集, 2012, 日本気象学会, Japanese
  2012 - 2012
• 熱帯対流圏界層における水平移流に伴う脱水
  稲飯洋一; 長谷部文雄; 藤原正智; 塩谷雅人; 西憲敬; 荻野慎也; 岩崎杉紀; VOEMEL Holger
  日本気象学会東北支部気象研究会予稿集, 2011, Japanese
  2011 - 2011
• Diurnal wind variations in the UT/LS region detected in MU-radar and reanalysis data
  Takatoshi Sakazaki; Masatomo Fujiwara; Hiroyuki Hashiguchi
  IGAC/SPARC Joint Meeting, 25 Oct. 2009, English
  25 Oct. 2009 - 25 Oct. 2009
• MUレーダーを用いた下部成層圏・上部対流圏の風の日変動の解析
  坂崎貴俊; 藤原正智; 橋口浩之
  第23回 大気圏シンポジウム, 26 Feb. 2009, Japanese
  26 Feb. 2009 - 26 Feb. 2009
• WINDAS・MUレーダーを用いた下層大気の風の日変動の解析
  坂崎貴俊; 藤原正智; 橋口浩之
  日本気象学会2008年度秋期大会, 20 Nov. 2008, Japanese
  20 Nov. 2008 - 20 Nov. 2008
• Climatological study of atmospheric ozone and turbulence from multiyear MU radar and ozonesonde measurements in Japan
  N.M. Gavrilov; S. Fukao; M. Fujiwara; H. Nakane; H. Hashiguchi; M. Yamamoto
  Quadrennial Ozone Symposium, 29 Jun. 2008, English
  29 Jun. 2008 - 29 Jun. 2008
• Variations of atmospheric ozone and turbulence in the tropical tropo-stratosphere from simultaneous radar and ozonesonde measurements in Indonesia
  N.M. Gavrilov; S. Fukao; M. Fujiwara; H. Nakane; H. Hashiguchi; M. Yamamoto
  Quadrennial Ozone Symposium, 29 Jun. 2008, English
  29 Jun. 2008 - 29 Jun. 2008
• P386 熱帯下部成層圏における水蒸気の長期変動(1)
  藤原 正智; 長谷部 文雄; 塩谷 雅人; Vomel H; 荻野 慎也; 岩崎 杉紀; 西 憲敬; 柴田 隆; Oltmans S. J
  大会講演予講集, 2008, 日本気象学会, Japanese
  2008 - 2008
• P313 キリバスにおけるに熱帯圏界面付近の雲の頻度分布
  岩崎 杉紀; 松井 一郎; 塩谷 雅人; 藤原 正智; 長谷部 文雄; 清水 厚; 杉本 伸夫
  大会講演予講集, 2008, 日本気象学会, Japanese
  2008 - 2008
• P346 熱帯西太平洋の対流圏界面領域におけるCirrusの観測
  藤原 正智; 岩崎 杉紀; 清水 厚; 塩谷 雅人; 松浦 弘和; 稲飯 洋一; 長谷部 文雄; 松井 一郎; 杉本 伸夫; 岡本 創; 西 憲敬; 濱田 篤; 米山 邦夫; Immler Franz
  大会講演予講集, 2007, 日本気象学会, Japanese
  2007 - 2007
• P330 キリバス、ビアックに設置したライダによるSubvisual Cirrus Cloudsの同時観測
  岩崎 杉紀; 松井 一郎; 清水 厚; 杉本 伸夫; 塩谷 雅人; 柴田 隆; 藤原 正智; 長谷部 文雄
  大会講演予講集, 2007, 日本気象学会, Japanese
  2007 - 2007
• Results from the Soundings of Ozone and Water in the Equatorial Region (SOWER)/Pacific Mission
  Shiotani, M; F. Hasebe; H. Voemel; M. Fujiwara; N. Nishi; S. J. Oltmans
  Japan-U.S. Seminar, Kyoto, Japan, Mar. 2001, English
  Mar. 2001 - Mar. 2001
• SOWER/Pacific - the Shoyo-maru Cruise in the Equatorial Eastern Pacific
  Shiotani, M; M. Fujiwara; F. Hasebe; S.-P. Xie; H. Hashizume; T. Watanabe; Shoyo-maru Mission Team
  Quadrennial Ozone Symposium, Sapporo, Japan, Jul. 2000, English
  Jul. 2000 - Jul. 2000
• SOWER/Pacific - 照洋丸による赤道東太平洋域のオゾン観測 -
  塩谷雅人; 長谷部文雄; 藤原正智; 照洋丸観測チーム; SOWER サイエンスチーム
  第10回大気化学シンポジウム, 豊橋市, Jan. 2000, Japanese
  Jan. 2000 - Jan. 2000
• SOWER/Pacific 1998/99年集中観測 - 対流圏オゾンの変動 -
  塩谷雅人; 長谷部文雄; 豊田賢二郎; 西憲敬; 藤原正智; 小川利紘; H. Voemel; S. Oltmans; K. Gage
  日本気象学会1999年度秋季大会, 福岡市, Nov. 1999, Japanese
  Nov. 1999 - Nov. 1999

• 大気海洋物理学基礎論, 2024年, 修士課程, 環境科学院
• 一般教育演習(ﾌﾚｯｼｭﾏﾝｾﾐﾅｰ), 2024年, 学士課程, 全学教育

• Japan Geoscience Union
• The Japan Society of Atmospheric Chemistry
• American Meteorological Society
• Meteorological Society of Japan
• American Geophysical Union

• フンガ・トンガ＝フンガ・ハアパイ海底火山噴火の気候とオゾン層へのインパクト
  科学研究費補助事業
  Apr. 2024 - Mar. 2028
  藤原正智
  日本学術振興会, 基盤研究(B), 北海道大学, 24K00700
• Atmospheric Turbulence and Cirrus Cloud Variability by Equatorial Atmospheric Radar and HYFLITS Sonde Observations
  Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), Japan Society for the Promotion of Science
  Apr. 2024 - Mar. 2027
  Hubert Luce, Matomo Fujiwara, Hiroyuki Hashiguchi
  日本学術振興会, 基盤研究(B), 京都大学, 24K03091
• エルニーニョ・南方振動気候モデル実験による重力波と赤道準2年振動の新知見
  科学研究費助成事業
  01 Apr. 2022 - 31 Mar. 2026
  河谷 芳雄; 藤原 正智; 渡辺 真吾
  赤道準2年振動（QBO）気候モデル国際比較プロジェクト（QBOi）のco-leadsとして、国際共同研究を主導した。その中で現在進めているENSO－QBO実験を主責任者として取り纏め、3つの研究グループに分けて解析を続けて初期結果が出てきた。エルニーニョ実験とラニーニャ実験を比較すると、どの気候モデルもエルニーニョ実験の方がQBO周期が短く、観測と整合的である。しかし周期の変調にはモデル間で大きなばらつきがあり、その原因を運動量収支解析により調べている。
  典型的なQBO東西風サイクルが観測された1980年7月から1983年6月の36か月間を対象に、大気大循環モデルを全球再解析データを用いて初期値化したのち、月初から月末まで1か月間のTranspose-AMIP実験を毎月実施することにより、様々なQBO位相におけるQBO東西風の誤差成長の様子を調べた。使用した大気大循環モデルの弱点として、QBO東風シアー層の下降時の下降速度を過小評価する傾向が見られた。運動量収支の解析結果とともに、関連する国際会議で発表した。
  本年度は、4種の再解析データから計算した変形オイラー平均（TEM）方程式系の全項と残差項およびその全変数について、それらの気候値の比較・検証をおこなった論文を執筆し、Atmospheric Chemistry and Physics誌に投稿した。また、国際的な再解析データ比較検証活動S-RIP Phase 2の計画立案に関わりつつ、国際会議および国内学会にてこれに関連する招待講演をおこなった。また、基準高層観測網（GRUAN）の会議に出席し、ラジオゾンデ観測がQBOの状態監視の鍵であることについて議論した。
  日本学術振興会, 基盤研究(B), 23K22574
• エルニーニョ・南方振動気候モデル実験による重力波と赤道準2年振動の新知見
  科学研究費助成事業
  01 Apr. 2022 - 31 Mar. 2026
  河谷 芳雄; 藤原 正智; 渡辺 真吾
  日本学術振興会, 基盤研究(B), 国立研究開発法人海洋研究開発機構, 22H01303
• Identification and Separation of Volcanic and Natural Climate Variability Signals
  Grants-in-Aid for Scientific Research
  08 Mar. 2023 - 31 Mar. 2025
  藤原 正智; DOGAR MUHAMMAD
  Dr. Dogar has analyzed data from his ensemble numerical experiments using the Geophysical Fluid Dynamics Laboratory (GFDL)'s coupled atmosphere-ocean climate model (GFDL-CM2.1) run on the Hokkaido University's high-performance supercomputing facility in the previous year. Dr. Dogar has written up a journal paper manuscript titled "ENSO and NAO Linkage to Strong Volcanism and Associated Post-Volcanic High-Latitude Winter Warming", which has been published in Geophysical Research Letter in January 2024. The main message of the paper is, "Our simulations strongly suggest that the post-eruption Eurasian winter warming is caused by a post-eruption positive NAO phase and not by coexisting ENSO-preconditioned variability." Furthermore, using the same simulation data set, Dr. Dogar has written up another manuscript titled "Volcanic Whispers: Decoding Post-eruption Winter Cooling Mysteries in the Middle East and North Africa - Unraveling ENSO and NAO Dynamics" and submitted it to another journal.
  Dr. Dogar attended the American Geophysical Union (AGU) Fall Meeting 2023 in December 2023 and the US CLIVAR's Workshop on Confronting Earth System Model Trends with Observations: The Good, the Bad, and the Ugly and presented these works there.
  Japan Society for the Promotion of Science, Grant-in-Aid for JSPS Fellows, Hokkaido University, 22KF0010
• 春季東南アジアにおける大気汚染の発生機構： コールドサージに伴うオゾン変動の解明
  科学研究費助成事業
  01 Apr. 2022 - 31 Mar. 2025
  荻野 慎也; 藤原 正智
  日本学術振興会, 基盤研究(C), 国立研究開発法人海洋研究開発機構, 22K12367
• 気候変動における火山噴火影響と自然変動シグナルの同定と分離
  科学研究費助成事業
  22 Apr. 2022 - 31 Mar. 2024
  藤原 正智; DOGAR MUHAMMAD
  日本学術振興会, 特別研究員奨励費, 北海道大学, 22F22012
• The Quasi-biennial Oscillation and Gravity Wave Modulation by the El Nino Southern Oscillation
  Grants-in-Aid for Scientific Research
  01 Apr. 2018 - 31 Mar. 2022
  Kawatani Yoshio
  El Nino Southern Oscillation (ENSO)-equatorial biennial oscillation (QBO) experiments were conducted using a climate model in which gravity wave parameterization is not included, and various observational and reanalysis data were analyzed to investigate QBO modulation mechanism by ENSO. More gravity waves were excited during the El Nino period, which accelerate the downward speed of the lower stratospheric QBO. Although the equatorial upwelling that prevents the downward progataton of the QBO was larger during the El Nino than La Nina, effects of gravity wave was larger during El Nino, resulting in a shorter period. Models which include gravity wave parameterization did not show such QBO modulation due to unchanged gravity wave sources assumed in the parameterization.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Japan Agency for Marine-Earth Science and Technology, 18H01286
• Study on the climate response to the major volcanic eruptions
  Grants-in-Aid for Scientific Research
  01 Apr. 2016 - 31 Mar. 2020
  Fujiwara Masatomo
  The global response of surface temperature and stratospheric circulation to the three major eruptions, i.e., Mount Agung in March 1963, El Chichon in April 1982, and Mount Pinatubo in June 1991, was investigated using the multiple linear regression analysis method. Data used are several of the global atmospheric reanalysis data sets, whose quality has also been evaluated extensively at the same time under an international project named S-RIP proposed and started by myself in 2011. It was found that the global surface temperature generally decreased through about 1 year after each of the eruptions, but that the magnitude of the decrease in previous studies was generally overestimated. The response of the stratospheric circulation was found to differ for the three eruptions very largely.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 16K05548
• Elucidating the robust features of the stratosphere by using data from satellite measurements and reanalyses
  Grants-in-Aid for Scientific Research
  01 Apr. 2015 - 31 Mar. 2019
  Sakazaki Takatoshi; SHIOTANI Masato; FUJIWARA Masatomo; HAMILTON Kevin
  Recently, it is widely recognized that the stratosphere plays an important role on the climate system of the earth. There are several datasets for representing the state of the stratosphere, including data from satellite measurements and reanalysis datasets (the best estimate obtained through the data assimilation technique). However, the difference among these datasets were not reported in a straightforward manner. This study, with a particular focus on diurnal cycle, comprehensively analyzed these data to report such difference quantitatively and elucidate their causes. We found that only a particular mode of the diurnal cycle shows a clear difference between the satellite and reanalysis data. Also, even observations have a non-negligible difference depending on the satellites. The reanalysis data is greately influenced by the assimilation of satellite measurements especially for the middle and upper stratosphere.
  Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists (B), Kyoto University, 15K17761
• Synthesis of dynamical and chemical descriptions on the atmospheric processes in the Tropical Tropopause Layer
  Grants-in-Aid for Scientific Research
  30 May 2014 - 31 Mar. 2019
  Hasebe Fumio; SUGAWARA Satoshi; ISHIDOYA Shigeyuki; INAI Yoichi; BELIKOV Dmitry
  Coordinated observations of SOWER-Cryogenic air sampling were conducted in the western tropical Pacific in an attempt to clarify the stratospheric response to climate forcing. Vertical profiles of various quantities, including three independent variables, i.e., water vapor mixing ratio, age of air, and gravitational separation, that describe the stratospheric transport processes, are successfully obtained. Analyses with the aid of backward air trajectories and numerical simulations reveal many interesting features, above expectations, leading us to a mutually consistent understanding among all observables. The knowledge accumulated from observational evidences taken from ozone, water vapor and cloud particle radiosondes under SOWER campaigns aimed at the tropical tropopause layer and the stratosphere will be a foundation useful for the study on the outflow of atmospheric pollutants associated with the summer Asian monsoon circulation.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (S), Hokkaido University, 26220101
• Mechanism of the Quasi-Biennial Oscillation modulation associated with climate change
  Grants-in-Aid for Scientific Research
  01 Apr. 2014 - 31 Mar. 2018
  KAWATANI Yoshio; WATANABE Shingo; SATO Kaoru
  The Quasi-biennial oscillation (QBO) and semi-annual oscillation (SAO) was successfully simulated by the climate model without non-stationary gravity wave parameterization. The mechanism of interannual variability of stratospheric water vapor was clarified by analyzing the climate model and satellite data. The experiments of the QBO modulation in a future climate were done following the international project, and modulations of the QBO were investigated.
  We participated in the stratosphere reanalyses intercomparison project (S-RIP). Several studies are published, such as representations of equatorial stratospheric zonal winds, comparison of mean meridional circulation and mixture processes, comparison of seasonal and interannual variations in dynamical fields etc.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Japan Agency for Marine-Earth Science and Technology, 26287117
• Development of an ultra-small tandem balloon system for tropopause observation
  Grants-in-Aid for Scientific Research
  01 Apr. 2014 - 31 Mar. 2017
  Saito Yoshitaka
  The purpose of this research was to develop a balloon experiment system which keeps flying for several weeks while moving up and down the tropopuase at sunrise and sunset. First, we quantitatively showed that the system can be realized by a tandem balloon system connecting a small zero-pressure balloon with a volume of 100 cubic meters and a super-pressure balloon with a volume of 10 cubic meters. Then, we developed the most important element, the super-pressure balloon, and also the satellite communication system. Finally, we successfully developed a 10 cubic meters super-pressure balloon with pressure resistance performance of 10,000 Pa, a very light weight of 3 kg and almost no gas leakage. We also established a compact communication system using Iridium satellites.
  Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Exploratory Research, Japan Aerospace EXploration Agency, 26630448
• 熱帯対流圏界層内統合観測による「巻雲粒子個数濃度パラドックス」の解明
  科学研究費助成事業
  01 Apr. 2014 - 31 Mar. 2015
  長谷部 文雄; 藤原 正智; 塩谷 雅人; 林 政彦; 柴田 隆
  消耗品の購入と学会参加等の活動を開始したが、基盤研究(S)に採択されたため、経費を返還し事業を廃止する。
  日本学術振興会, 基盤研究(A), 北海道大学, 26247077
• Development of a balloon-borne chilled-mirror hygrometer for climate monitoring
  Grants-in-Aid for Scientific Research
  2010 - 2012
  FUJIWARA Masatomo
  We have developed a chilled mirror hygrometer for the climate monitoring, which accurately measures atmospheric water vapor from the surface to the lower stratosphere. Additionally, we re-evaluated the relative humidity measurement uncertainty of the RS-06G operational radiosonde, and developed a cloud particle sensor for balloon sounding. These measurement systems can make more reliable and stable water vapor measurements.
  Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists (B), Hokkaido University, 22740306
• Study on the dehydration in the Tropical Tropopause Layer by observations of minor constituents and analyses of 4-D assimilation field
  Grants-in-Aid for Scientific Research
  2009 - 2012
  HASEBE Fumio; SHIOTANI Masato; FUJIWARA Masatomo; NISHI Noriyuki; OGINO Shinya; MIYAZAKI Kazuyuki; SHIBATA Takashi; YAMAZAKI Koji; IWASAKI Toshiki
  The long-term trend of the water concentration in the tropical stratosphere has been estimated from in situ observations by radiosondes.Supersaturations close to 80 % in relative humidity with respect to ice have been observed in cirrus clouds advected horizontally in the Tropical Tropopause Layer (TTL). General features of dehydration associated with horizontal advection for the air parcels slowly ascending in the TTL have been observationally described for the first time by investigating the water mixing ratio of the observed air parcels and their minimum saturation mixing ratio estimated along the trajectories upstream.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, 21244072
• Study of transport and photochemistry around the tropical tropopause using Chemistry Climate Models
  Grants-in-Aid for Scientific Research
  2007 - 2009
  FUJIWARA Masatomo
  There exists significant sub-seasonal variability in temperature and other parameters around the tropical troomuse. This is due to equatorial waves, intra-seasonal oscillations (ISOs), and other disturbances that are generated by tropical organized convection. Therefore, appropriate representation of tropical convection and tropical disturbances is crucial even for the Chemistry Climate Models (CCMs) that simulate and project stratospheric ozone, since these waves significantly influence the stratosphere-troposphere transport processes and help determine the coldest temperatures, affecting the dehydration processes in the tropical tropopause region. In this study, the wave activity in temperature and zonal and meridional winds at 100hPa in the tropics is analyzed for four CCMs that produced high time frequency winds and temperatures (CCSRNIES, CMAM, MRI, and WACCM) and for five reanalysis data sets (ERA40, ERA-Interim, JRA25, NCEP/NCAR (NCEP1), and NCEP-DEO AMIP-II (NCEP2)), using a zonal-wavenumber-frequency spectral analysis method with a equatorially symmetric-antisymmetric decomposition.
  Features commonly observed in all data sets are equatorial Kelvin waves and mixed RossbY gravity OMRG) waves. ISOs, at frequencies smaller than O. 05 cycle per day, are mostly not statistically significant with respect to the background spectra estimated here; however, largest power is found in these regions. The activity for equatorial Kelvin waves, MRG waves, and symmetric eastward-moving ISO is defined as the integration of power spectral density in the respective zonal-wavenumber-frequency region for each wave/disturbance. The statistical significance is considered only for Kelvin and MRG waves. The ISO activity here is the upper limit. Results indicate that five reanalysis data sets have very different wave activities. The Kelvin and MRG wave activities in ERAs are 2-3 times greater than those in NCEPs; those in JRA25 are close to the average. The ISO activity (the upper limit) is rather similar for the five reanalysis data sets. The wave activities in the four CCMs are generally within the range of those in the reanalysis data. WACCM shows the greatest Kelvin and MRG wave activities, which are comparable to those in ERAs. CCSRNIES shows the smallest Kelvin wave activity, and MRI shows the smallest MRG activity. The ISO activity (the upper limit) in the CCMs is greater than that in the five reanalysis data sets except for CCSRNIES.
  The above results indicate that the reanalysis data currently available do not give the actual wave activities due to their large discrepancy. Analysis of radiosonde data and GPS occultation temperature data is necessary to investigate the actual wave activities.
  Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists (B), Hokkaido University, 19740283
• Quantification of water vapor budget in the stratosphere
  Grants-in-Aid for Scientific Research
  2007 - 2008
  SHIOTANI Masato; KAWAMOTO Nozomi; FUJIWARA Masatomo; JOACHIM Urban
  成層圏における熱バランスやオゾン化学に対して決定的な影響を与える水蒸気の変動について調べた. 特に熱帯域に注目して, いくつかの衛星観測データと定点観測ながら精度の高い水蒸気ゾンデデータとの比較・検討をおこない, 衛星観測のデータ質についての知見を得た. さらに, 熱帯下部成層圏における水蒸気混合0比の過去約15年にわたる年々変動について見たところ, さまざまな変動要因は存在するものの, 全体としては増加傾向を示すことがわかった.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Kyoto University, 19540461
• Study on the dehydration processes in the tropical tropopause layer by measurements of minor constituents and numerical modeling
  Grants-in-Aid for Scientific Research
  2006 - 2007
  HASEBE Fumio; SHIOTANI Masato; FUJIWARA Masatomo; NISHI Noriyuki; SHIBATA Takashi; IWASAKI Toshiki
  The purpose of the present study is to better understand the dehydrationprocesses in the Tropical
  Tropopause Layer and to monitor the water vapor trend in the tropical lower stratosphere by conducting radiosonde observations using frostpoint hygrometers in the western for the water tropical Pacific. Uniqueness of this project lies in the coordinated observation strategy for the water vapor "match", that is, to operate a network of stations to catch the same air parcels twice or more toquantify the dehydrated amount for the specific air observed. The main findings so far obtained from the accumulated data are: There are close relationships between the water amount of the observed air parcel and the saturation water mixing ratio along the trajectories of the corresponding air parcel reflecting the meteorological conditions such as the location of the stations, isentropic levels, season and ENSOstatus. Specific features of the sonde profiles such as a jump in the relative humidity could be traced as a difference in the origin of the air parcel on an individual sounding basis. This fact provides us some confidence in identifying the "match" pairs in spite of the difficulties in such an attempt. Comparisons of the water profiles with cirrus distributions observed by lidars show interesting results on the condensation and super saturation for the air. Some of these results have been presented in international conferences and published in the literature. Unfortunately, the collaborative observations with TC4 did not take place due to the budget problem in US. However, our data have contributed to the validation of satellite observations. Finally it will be worth mentioning that we have conducted some test flights with Lyman alpha hygrometer and are preparing some assimilation runs by incorporating observed data for the future extension of the current study.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, 18204041
• Observational study on cirriform clouds in the tropical upper troposphere
  Grants-in-Aid for Scientific Research
  2004 - 2006
  FUKAO Shoichiro; YAMAMOTO Masayuki; NISHI Noriyuki; OKAMOTO Hajime; KUMAGAI Hiroshi; OHNO Yuichi
  Cirriform clouds (cirrus, cirrostratus, cirrocumulus) existing in the upper part of the troposphere consist almost entirely of ice particles, and are known to play a significant role in regulating the radiation balance of the earth-atmosphere system. However, mechanisms which control generation, maintenance, and dissipation of cirriform clouds in the tropics are not well understood due to a scarcity of observations in the region. In this research project, an observation campaign of cirriform clouds using VHF wind profiler to observe vertical wind, W-band Doppler radar to observe falling velocity of ice particles in clouds, lidar to observe small-sized ice particles, weather radar to observe precipitating particles, and radiosonde to observe vertical profiles of temperature and humidity has been carried out at Kototabang, West Sumatra, Indonesia (at latitude 0.2 degrees south and longitude 100.32 degrees east).
  From detailed data analysis using data derived from the observation campaign, time-altitude variations of vertical wind in and around tropical cirriform clouds has been shown for the first time. Further, effects of vertical wind on particle falling velocity in cirriform clouds are studied in detail. Using vertical wind data observed by a VHF wind profiler installed at Kototabang (the Equatorial Atmosphere radar), vertical wind changes in the middle and upper troposphere associated with eastward-moving synoptic-scale cumulus activity (Yamamoto et al., in press), fine time-altitude variations of vertical wind in the precipitating stratiform region (Nishi et al., 2007) and vertical motion of cirriform clouds in the middle troposphere (Seto et al., 2006) have been studied and published. This research project has demonstrated that a combination of VHF wind profiler and other instruments to observe inside of cirriform clouds is useful to observe processes related to such clouds.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), KYOTO UNIVERSITY, 16340139
• 船舶からの水蒸気ゾンデ観測による熱帯西太平洋対流圏界面領域での脱水過程の解明
  科学研究費助成事業
  2004 - 2005
  藤原 正智
  2004年12月から2005年1月にかけて実施した海洋研究開発機構の海洋地球研究船「みらい」における水蒸気・オゾンゾンデ観測のデータ、および、同時期のキリバス、インドネシア、ベトナムにおける水蒸気・オゾンゾンデ観測のデータを解析した。流跡線解析の手法を用いて、観測点間における同一空気塊の変質を抽出することを試みた。流跡解析の結果、全38回の観測中、8つの観測ペアーにおいて、同一空気塊を観測していることが判明し、水蒸気濃度変化およびオゾン濃度変化について考察した。しかし、期待していた脱水(水蒸気減少)を示したペアーは1例しかなく、確定的な議論は出来なかった。今後の課題として、水蒸気センサーの精度のさらなる向上、流跡線計算の妥当性・現実性の検証、観測ペアー数の増大などの必要性が分かった。
  「みらい」においては、ミー散乱ライダーによる上層雲等の連続観測および3時間おきのラジオゾンデ観測も実施されたので、これらのデータを用いて、圏界面付近を東進する大規模な擾乱に伴う圏界面領域の雲粒子(脱水過程に伴う生成物)の変動についてデータ解析を行った。東進擾乱の寒偏差が「みらい」上空にやってくると、圏界面領域内に雲粒子が出現した。しかし、寒偏差が去った後も引き続き雲粒子が観測され、しかも夜間に数kmに渡って降下するという顕著な日変化が見い出された。さらに、ライダーの偏光解消度などの情報から、対流圏界面領域の雲と高度12km付近の雲とでは、雲物理学的性質が顕著に異なることも見い出された。大規模東進擾乱に伴う熱帯対流圏界面付近の雲粒子変動については、数年前に他のグループによる簡単な報告があるのみで、今回はじめて詳細な変動や雲粒子の特質が観測されたと言える。観測された諸性質を完全に説明するには今しばらくの考察が必要であるが、1年以内には投稿論文としてまとめられるであろうと考えている。
  上記二点の結果について、2月末に横浜で開催された「ブルーアース06みらいシンポジウム」にて発表し、他の研究者らと議論、情報交換を行った。
  また、過去の観測およびデータ解析の結果を、共同研究者らと投稿論文にまとめて発表した。
  日本学術振興会, 若手研究(B), 北海道大学, 16740264
• Study on the dehydration processes in the tropical tropopause layer
  Grants-in-Aid for Scientific Research
  2003 - 2005
  HASEBE Fumio; SHIOTANI Masato; FUJIWARA Masatomo; NISHI Noriyuki; SHIBATA Takashi; IWASAKI Toshiki
  Ozone and water vapor sonde observations were conducted in December 2003, December 2004 to January 2005, and December 2005 to January 2006 for the purpose of studying the dehydration processes in the tropical tropopause layer (TTL) and estimating long-term trend of water vapor in the tropical lower stratosphere. Appreciable water vapor trend has not been detected so far. Observational stations were chosen along the air trajectory in the TTL at Tarawa, Biak, Bandung, Kototabang, and Hanoi. The opportunity of "Mirai" cruise was also taken. There found good correspondence between the retained amount of water in the air and the coldness the corresponding air mass experienced prior to observation. Water vapor "match" in which the same air parcel is observed twice or more along the trajectories is useful to make such estimates more reliable. Analyses are currently under way paying special attention to the estimation of observational uncertainty in the sonde data, objective identification of "match" pairs, detection of penetrating convective clouds, and consideration of possible bias in the meteorological field. Lidar observations of subvisible cirrus clouds (SVC) were also made to supplement sonde observations. It will enable us to infer the altitude of SVC in the water vapor profiles and to know the atmospheric condition surrounding the ice particle in SVC. Detailed investigation is under way for the case where the degree of super saturation shows interesting change in the SVC. For the modeling study, on the other hand, a new framework with the use of mass-weighted isentropic zonal mean was established. It was used to study the role of transport in the seasonal variation of total ozone. The impact of changing assimilated meteorological variables on ozone simulations is also investigated. These results will be extended in the successive studies in the future.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), HOKKAIDO UNIVERSITY, 15204043
• Study on equatorial cumulous convection and atmospheric waves using radiosonde observations and data assimilation modeling
  Grants-in-Aid for Scientific Research
  2000 - 2002
  NAKAMUR Atakuji; TSUDA Toshitaka; HORINOUCHI Takeshi; NISHI Noriyuki; TAKEMI Tetsuya; FUJIWARA Masatomo
  In the equatorial region, cumulous convections are extremely active which generate atmospheric waves. These waves propagate upward, affecting the circulations in the lower and middle atmospheres, as well as transporting energy into the thermosphere. In this study, we clarified the mechanisms underlying the convection and the atmospheric waves by comparing the details of the observational results and the four dimensional dataset produced by the numerical modeling by means of data assimilation technique. We, first, analyzed the observational dataset accumulated so far, and then new dataset collected by a novel precise observation techniques is utilized. Precise water vapor measurement around the tropopause was carried out in Indonesia, and the transport associated with the convective activity has been clarified. Airglow imaging observation over one year in Indonesia has revealed the climatology of small scale gravity waves in the mesopause region for the first time, and clear association with horizontal distributions of cumulous clouds has been found. A long term observation by the MLT radars clarified the relation between the intraseasonal variations in the MLT region and atmospheric wave activity in the lower atmosphere. Three dimensional modeling using these observational data clearly showed the gravity waves excited by the cumulous convection propagate into the mesospause region and break there. Further comparisons with the airglow imaging observations clarified the mechanism of gravity wave generation, propagation, breaking and associated atmospheric instability. Input from the new satellite data and further improvement of modeling such as extension of the simulation space and improvement of resolutions would greatly contribute to the understanding of global impact of the atmospheric waves in the lower and middle atmosphere.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), KYOTO UNIVERSITY, 12440127
• 熱帯地域における大気波動に伴う成層圏-対流圏大気交換過程
  科学研究費助成事業
  2000 - 2002
  藤原 正智
  1.京都大学とインドネシア航空宇宙庁によりインドネシア共和国スマトラ島コトタバンに設置された赤道大気レーダー(Equatorial Atmosphere Radar)のデータ解析を行い、対流圏界面領域の物質輸送に重要な役割を果たしているはずである乱流強度の変動の様子を世界で初めて明らかにし、さらにそれを引き起こしている大気擾乱の特定を行った。その結果は、論文リストに示すように2本の論文として発表した。
  2.ラジオゾンデ搭載用で安価で操作が容易でありながら、鏡面冷却方式という高精度な測定原理を持つ商用水蒸気センサーSnow Whiteについて、これまで2年間の熱帯地域における試験運用の結果を2本の論文にまとめ、Joumal of Atmospheric and Oceanic Technology誌に投稿した(2003年3月現在、2回目の査読中)。また、6月にはキリバス共和国クリスマス島、10月にはスリナム共和国、1月にはインドネシア共和国にてSnow Whiteやオゾンゾンデ等の同時集中観測を行い、成層圏対流圏大気交換過程に関する観測的研究を実施した。現在データ解析を行っている。
  3.東京大学気候システム研究センター・国立環境研究所所有の大気大循環モデルに使用されている放射コードと、熱帯での大気観測プロファイルデータとを用いて、放射加熱・冷却率プロファイルの算出を行い、熱帯上部対流圏〜対流圏界面領域の放射の観点からの特徴を明らかにした。現在2本の論文を共同で準備しており、1本目は、熱帯上部対流圏の気温微細構造が水蒸気の放射過程によって形成されており、さらにこのことが同領域の東風ジェットの成因となっていることを論じたものであり、2本目は英米の研究者とともに異なる放射コードを持ち寄り放射計算結果の相違を議論したものである。
  4.論文リストに示すように、前年度までに実施したいくつかの研究を、共同研究者とともにまとめて発表した。
  日本学術振興会, 特別研究員奨励費, 00J06668
• 大気波動に伴う成層圏対流圏大気交換過程
  科学研究費助成事業
  1998 - 1999
  藤原 正智
  日本学術振興会, 特別研究員奨励費, 東京大学, 98J04543