Researcher basic information

• 博士(理学), 京都大学

• https://researchmap.jp/read0150243?lang=en

• https://jglobal.jst.go.jp/detail?JGLOBAL_ID=201001030025965723
• http://wwwoa.ees.hokudai.ac.jp/people/horinout/

• 201001030025965723

• Natural Science, Atmospheric and hydrospheric sciences

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

Research activity information

• Jan. 2015, JMSJ Award
  Takeshi Horinouchi
• Jan. 2013, JMSJ Award
  Takeshi Horinouchi
• 2004, 大林奨励賞
  Japan
• 1998, 山本・正野論文賞
  Japan

• Fostering tropical cyclone research and applications with Synthetic Aperture Radar
  Alexis Mouche; Arthur Avenas; Paul Chang; Bertrand Chapron; Théo Cévaër; Clément Combot; Joseph Courtney; Quentin Febvre; Ralph C. Foster; Antoine Grouazel; Masahiro Hayashi; Takeshi Horinouchi; Yasutaka Ikuta; Isoguchi Osamu; Christopher R. Jackson; Zorana Jelenak; John A. Knaff; Sébastien Langlade; Jean-Renaud Miadana; Frédéric Nouguier; Masato Ohki; Clément Pouplin; Tyler W. Ruff; Charles R. Sampson; Joseph Sapp; Shimada Udai; Takeo Tadono; Taiga Tsukada; Léo Vinour
  Remote Sensing of Environment, Jan. 2026
  English, Scientific journal
• A Feasibility Study on Improving Tropical‐Cyclone Inner‐Core Structure Based on Data Assimilation of Inner‐Core Atmospheric Motion Vectors
  Satoki Tsujino; Takeshi Horinouchi
  Journal of Geophysical Research: Atmospheres, 16 Oct. 2025
  English, Scientific journal, Abstract
  The present operational estimation of the tropical cyclone (TC) intensity is made by subjectively combining observational methods including the Dvorak technique. However, as the kinds and frequencies of satellite observations are increased, it is desirable to switch to physics‐based objective analysis. This study is conducted to test its feasibility by examining the assimilation of high‐resolution atmospheric motion vectors (AMVs) obtained by a recently proposed method. Even though the method can retrieve low‐level high‐speed winds near the inner edge of the eyewall cloud, it cannot directly measure the maximum wind speed, which is normally achieved in the eyewall. On the basis of an ensemble Kalman filter assimilation system, observing system simulation experiments (OSSEs) are performed by assimilating pseudo‐AMV observations created from a nature run during the mature stage in a real TC. Mimicking the real AMVs, the pseudo‐observations are limited to low‐level AMVs in the eye without the maximum wind in the eyewall. The AMV assimilation limited to the eye reduces the spread of the TC‐center position among the ensemble members. Although the present OSSE has a limitation to assume that the model used is unbiased and highly dense AMVs are always obtained in a vertical layer of the eye, these results suggest that assimilating high‐resolution low‐level AMVs in the eye can be a hopeful approach to realize improvement of the TC structure with small errors in the model for the physics‐based objective analysis of TC intensity in the future.
• Statistical Prediction of Tropical Cyclone Rapid Intensification with Explainable AI
  Takeshi Horinouchi; Takashi Yanase; Yuiko Ohta; Daisuke Matsuoka; Asanobu Kitamoto; Udai Shimada; Ryuji Yoshida; Hironori Fudeyasu
  Weather and Forecasting, Oct. 2025
  Scientific journal, Abstract
  Imperfectness of the state-of-the-art intensity forecasting of tropical cyclones (TCs) necessitates independent rapid intensification (RI) prediction schemes. Here, we report one derived with an explainable artificial intelligence Wide Learning (WL). The scheme, named Wide Learning–based TC rapid intensification prediction scheme (WRPS), version 1 (WRPS1), predicts RI in the western North Pacific by using twelve predictor variables representing environmental conditions and the state of TCs. Its prediction is based on a score that is a linear combination of whether or not (1 or 0) joint conditions on ranges of multiple variables are met, which is reproducible without WL. Relying on joint conditions allows WRPS to handle nonlinearity and interdependence among predictors, and the simpleness of the conditions provides explainability. A method to map an RI-prediction score to its probability is proposed and is used in WRPS. It is suggested that handling predictors favorable to RI when having moderate values, such as the current intensity, is a key for good RI prediction. It is demonstrated that quantifying the contribution of each predictor to the WRPS score helps one elucidate how the predictors jointly facilitated or hindered RI for each prediction case. The performance of WRPS1 is compared with RI predictions using the linear discriminant analysis, and WRPS1 is shown to perform well without using track predictions. The multiple linear regression analysis, which is customarily used for intensity prediction but not for RI prediction, is shown to perform well if the fraction of RI cases is increased when conducting regression.
  
  Significance Statement
  We developed a new scheme to predict rapid intensification of tropical cyclones, WRPS version 1, by using an explainable artificial intelligence. Its prediction is based only on 12 parameters, but it performs well. The WRPS prediction formula is simple and reproducible by using information available in the supplemental material of this paper. It is suggested that handling predictors favorable to RI when having moderate values, such as the current intensity, is a key for good RI prediction. It is demonstrated that quantifying the contribution of each predictor to the WRPS score helps one elucidate how the predictors jointly facilitated or hindered RI for each prediction case.
  
• Global Precipitation Experiment—A New World Climate Research Programme Lighthouse Activity
  Xubin Zeng; Lincoln Alves; Marie-Amélie Boucher; Annalisa Cherchi; Charlotte DeMott; A. P. Dimri; Andrew Gettelman; Edward Hanna; Takeshi Horinouchi; Jin Huang; Chris Lennard; L. Ruby Leung; Yali Luo; Meloth Thamban; Hindumathi Palanisamy; Sara C. Pryor; Marion Saint-Lu; Stefan P. Sobolowski; Detlef Stammer; Jakob Steiner; Bjorn Stevens; Stefan Uhlenbrook; Michael Wehner; Paquita Zuidema
  Bulletin of the American Meteorological Society, Feb. 2025, [Peer-reviewed]
  Scientific journal, Abstract
  The future state of the global water cycle and the prediction of freshwater availability for humans around the world remain among the challenges of climate research and are relevant to several United Nations Sustainable Development Goals. The Global Precipitation Experiment (GPEX) takes on the challenge of improving the prediction of precipitation quantity, phase, timing, and intensity, characteristics that are products of a complex integrated system. It will achieve this by leveraging existing World Climate Research Programme (WCRP) activities and community capabilities in satellite, surface-based, and airborne observations, modeling, and experimental research and by conducting new and focused activities. It was launched in October 2023 as a WCRP Lighthouse Activity. Here, we present an overview of the GPEX Science Plan that articulates the primary science questions related to precipitation measurements, process understanding, model performance and improvements, and plans for capacity development. The central phase of GPEX is the WCRP Years of Precipitation for 2–3 years with coordinated global field campaigns focusing on different storm types (atmospheric rivers, mesoscale convective systems, monsoons, and tropical cyclones, among others) over different regions and seasons. Activities are planned over the three phases (before, during, and after the Years of Precipitation) spanning a decade. These include gridded data evaluation and development, advanced modeling, enhanced understanding of processes critical to precipitation, multiscale prediction of precipitation events across scales, and capacity development. These activities will be further developed as part of the GPEX Implementation Plan.
• Compound weather and climate extremes in the Asian region: science-informed recommendations for policy
  R. Krishnan; Chirag Dhara; Takeshi Horinouchi; C. Kendra Gotangco Gonzales; A. P. Dimri; M. Singh Shrestha; P. Swapna; M. K. Roxy; Seok-Woo Son; D. C. Ayantika; Faye Abigail T. Cruz; Fangli Qiao
  Frontiers in Climate, 03 Jan. 2025, [Peer-reviewed]
  Scientific journal, Anthropogenic climate change has led to rapid and widespread changes in the atmosphere, land, ocean, cryosphere, and biosphere, leading to more pronounced weather and climate extremes globally. Recent IPCC reports have highlighted that the probability of compound extreme events, which can amplify risk, has risen in multiple regions. However, significant gaps remain in our understanding of the drivers and mechanisms behind these events. This concept paper discusses compound events in the Asian region in the context of its unique and diverse geographical settings, and regional climatic features including the seasonal monsoons. Notably, Asia is the world’s most disaster-affected region due to weather, climate, and water-related hazards. Therefore, an integrated understanding of how climate change will impact compound events in this region is essential for effective forewarning and risk mitigation. This paper analyzes three typologies of compound events in the Asian region, illustrating their regional complexity and potential linkages to climate change. The first typology pertains to compound floods, for example, the devastating floods in the Indus River Basin and adjoining Western Himalayas during 2022 caused by the combined effects of heavy monsoon rainfall, intense pre-monsoon heatwaves, glacier melt, and modes of climate variability. The second typology relates to compound heatwave-drought events that have prominently manifested in East and South Asia, and are linked to large-scale drivers of the land-atmosphere–ocean coupled system and local feedbacks. The third typology relates to marine extremes involving the compounding effects of ocean warming, sea-level rise, marine heatwaves, and intensifying tropical cyclones. We identify key knowledge gaps in understanding and predicting compound events over the Asian region and discuss advances required in science and technology to address these gaps. We also provide recommendations for the effective utilization of climate information towards improving early warning systems and disaster risk reduction.
• Wind Distribution in the Eye of Tropical Cyclone Revealed by a Novel Atmospheric Motion Vector Derivation
  Taiga Tsukada; Takeshi Horinouchi; Satoki Tsujino
  Journal of Geophysical Research: Atmospheres, 129, 9, American Geophysical Union (AGU), 04 May 2024, [Peer-reviewed]
  Scientific journal, Abstract
  
  Observations of wind distribution in the eye of tropical cyclones (TCs) are still limited. In this study, a method to derive atmospheric motion vectors (AMVs) for TCs is developed, where selection from multiple local rotation speeds is made by considering continuity among neighboring grid points. The method is applied to 2.5‐min interval image sequences of three TCs, Lan (2017), Haishen (2020), and Nanmadol (2022), observed by the Himawari‐8 satellite. The results are compared with AMVs derived from research‐based 30‐s Himawari‐8 special observations conducted for Haishen and Nanmadol, as well as with in‐situ dropsonde observations conducted for Lan and Nanmadol. In these storms, the AMVs obtained from the 2.5‐min interval images in the eye are found to be in good agreement with the dropsonde observations. Examinations of AMVs in the eye reveal transient azimuthal wavenumber‐1 features in all three TCs. These features are consistent with algebraically growing wavenumber‐1 disturbances, which transport angular momentum inward and accelerate the eye rotation. In the case of Lan, the angular velocity in the eye increased by approximately 1.5 times within 1 hr. This short‐term increase is further examined. Visualization of low‐level vorticity in the eye and angular momentum budget analysis suggest that angular momentum transport associated with mesovortices played an important role in the increase of tangential wind and the homogenization of angular velocity in the eye of Lan.
• Long‐Term Variability of Mean Winds and Planetary‐Scale Waves Around Venusian Cloud Top Observed With Akatsuki/UVI
  Takeshi Horinouchi; Toru Kouyama; Masataka Imai; Shin-ya Murakami; Yeon Joo Lee; Atushi YAMAZAKI; Manabu Yamada; Shigeto Watanabe; Takeshi Imamura; Javier Peralta; Takehiko Satoh
  Journal of Geophysical Research: Planets, Mar. 2024, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal, AbstractSince December 2015, Ultraviolet Imager (UVI) onboard Akatsuki has been observing Venus clouds at the wavelengths of 283 and 365 nm. Horizontal winds near the cloud top derived from the UVI images over ∼7 earth years are analyzed to elucidate spatial and temporal variability of the superrotation and planetary‐scale waves. Zonal winds averaged over the analysis period are asymmetric with respect to the equator, being faster in the southern hemisphere. This asymmetry varied temporarily and was occasionally reverted. Comparison of the winds from the two wavelengths suggests that it is uncertain whether the asymmetry is in the wind distribution or in the sensing altitude for winds. Mean zonal winds representing the superrotation exhibited broad low‐frequency variability with spectra resembling the red noise spectra. This is indicative of the presence of internal variability rather than responses to periodical external forcing. Planetary‐scale waves with zonal‐wavenumber 1 at periods around 4 and 5 days, which have been interpreted as equatorial Kelvin and Rossby waves, respectively, are quantified. While the ∼5‐day waves have nearly constant frequencies, the ∼4‐day waves have variable phase speeds that follow the superrotation speed. This result indicates that the ∼5‐day waves are likely to extend over a large depth below the cloud top and that the ∼4‐day waves are likely to be confined near the cloud top. Their possible generation mechanism through the coupling of Kelvin and Rossby waves is discussed. This study further reports wind variability of 10 to 15‐day periodicity, thermal‐tide structure, and comparison with minor species observations.
• Evaluations of Actual and Adjusted Wind–Pressure Relationship of Tropical Cyclone Using Aircraft-Assisted Best Track Data
  Sho Arakane; Takeshi Horinouchi
  SOLA, 2024, [Peer-reviewed], [Last author]
  English, Scientific journal
• A New Closure Assumption and Formulation Based on the Helmholtz Decomposition for Improving Retrievals for Vortex Circulations from Single-Doppler Radar Observations
  Satoki Tsujino; Takeshi Horinouchi; Udai Shimada
  Monthly Weather Review, 152, 1, 145, 168, American Meteorological Society, Jan. 2024, [Peer-reviewed]
  Scientific journal, Abstract
  
  Doppler weather radars are powerful tools for investigating the inner-core structure and intensity of tropical cyclones (TCs). The Doppler velocity can provide quantitative information on the vortex structure in the TCs. The generalized velocity track display (GVTD) technique has been used to retrieve the axisymmetric circulations and asymmetric tangential flows in the TCs from ground-based single-Doppler radar observations. GVTD can have limited applicability to asymmetric vortices due to the closure assumption of no asymmetric radial flows. The present study proposes a new closure formulation that includes asymmetric radial flows, based on the Helmholtz decomposition. Here it is assumed that the horizontal flow is predominantly rotational and expressed with a streamfunction, but limited inclusion of wavenumber-1 divergence is available. Unlike the original GVTD, the decomposition introduces consistency along the radius by solving all equations simultaneously. The new approach, named GVTD-X, is applied to analytical vortices and a real TC with asymmetric structures. This approach makes the retrieval of axisymmetric flow relatively insensitive to the contamination from asymmetric flows and to small errors in storm center location. For an analytical vortex with a wavenumber-2 asymmetry, the maximum relative error of the axisymmetric tangential wind retrieved by GVTD-X is less than 2% at the radius of the maximum wind speed. In practical applications, errors can be evaluated by comparing results for different maximum wavenumbers. When applied to a real TC, GVTD-X largely suppressed an artificial periodic fluctuation that occurs in GVTD from the aliasing of the neglected asymmetric radial flows.
  
  Significance Statement
  
  In tropical cyclone (TC) wind retrievals from single-Doppler weather radar observations, closure assumptions are required for the retrieval equations. The present study proposes a new closure allowing asymmetric radial winds and improving retrievals for TC winds in the previously developed technique. The relative error of the axisymmetric tangential wind in idealized vortices from the new approach is less than 2% at the radius of the maximum wind speed. In applying to a real TC with an elliptical eyewall, we found that the new approach can largely suppress an artificial evolution of the tangential winds in the previous retrieval technique.
• Objective satellite methods including AI algorithms reviewed for the tenth International workshop on tropical cyclones (IWTC-10)
  Quoc-Phi Duong; Anthony Wimmers; Derrick Herndon; Zhe-Min Tan; Jing-Yi Zhuo; John Knaff; Ibrahim Al Abdulsalam; Takeshi Horinouchi; Ryota Miyata; Arthur Avenas
  Tropical Cyclone Research and Review, Dec. 2023, [Peer-reviewed]
  English, Scientific journal
• Decadal Shift in Summer Precipitation Variability over East Asia in the Mid-2000s and Wave Propagation toward North America
  Shinji Matsumura; Takeshi Horinouchi
  Journal of Climate, 36, 8, 2483, 2496, American Meteorological Society, 15 Apr. 2023, [Peer-reviewed], [Last author, Corresponding author]
  Scientific journal, Abstract
  
  The East Asian summer climate displays a marked change after the late 1990s. This is principally due to a weakening of the Pacific–Japan (PJ) teleconnection pattern that was a dominant driver of precipitation variability over East Asia. Nevertheless, western Japan has frequently experienced heavy rainfall events over the past several years. Atmospheric reanalysis and observational datasets are used to investigate summer precipitation variability over East Asia in a view of interdecadal changes from 1979 to 2020. East Asian summer precipitation has increased the most in Japan, especially over and around the Southwest Islands in southern Japan, where cumulus convection has been more dominant for the characteristic of precipitation variability including mei-yu–baiu rainfall than frontal structure since the mid-2000s. Atmospheric analysis in vertical structures and convective instability indicates that moist instability is neutralized by cumulus convection over the southern East China Sea and off the Pacific coast of Japan, where recent warming in sea surface temperature (SST) along the Kuroshio exceeds the SST threshold for convection. This decadal shift in precipitation variability has a close relationship with the second precipitation mode over East Asia, which has taken the place of the PJ pattern as a leading driver of precipitation variability over western Japan in the past decade. The enhanced cumulus convection is enabled to act as a forcing mechanism for the Rossby wave train from East Asia toward North America along the westerly jet or for the eastward extension of the Silk Road pattern, which possibly favors a heatwave in the Pacific Northwest areas of North America.
• Venus cloud discontinuity in 2022
  J. Peralta; A. Cidadão; L. Morrone; C. Foster; M. Bullock; E. F. Young; I. Garate-Lopez; A. Sánchez-Lavega; T. Horinouchi; T. Imamura; E. Kardasis; A. Yamazaki; S. Watanabe
  Astronomy & Astrophysics, 672, L2, L2, EDP Sciences, 28 Mar. 2023, [Peer-reviewed]
  Scientific journal, Context. First identified in 2016 by the Japan Aerospace eXploration Agency (JAXA) Akatsuki mission, the discontinuity or disruption is a recurrent wave observed to propagate over decades at the deeper clouds of Venus (47–56 km above the surface), while its absence at the top of the clouds (∼70 km) suggests that it dissipates at the upper clouds and contributes to the maintenance of the puzzling atmospheric superrotation of Venus through wave-mean flow interaction.
  
  Aims. Taking advantage of the campaign of ground-based observations undertaken in coordination with the Akatsuki mission from December 2021 until July 2022, we undertook the longest uninterrupted monitoring of the cloud discontinuity to date to obtain a pioneering long-term characterisation of its main properties and to better constrain its recurrence and lifetime.
  
  Methods. The dayside upper, middle, and nightside lower clouds were studied with images acquired by the Akatsuki Ultraviolet Imager (UVI), amateur observers, and SpeX at the NASA Infrared Telescope Facility (IRTF). Hundreds of images were inspected in search of the discontinuity events and to measure key properties such as its dimensions, orientation, and rotation period.
  
  Results. We succeeded in tracking the discontinuity at the middle clouds during 109 days without interruption. The discontinuity exhibited properties nearly identical to measurements in 2016 and 2020, with an orientation of 91° ±8°, length of 4100 ± 800 km, width of 500 ± 100 km, and a rotation period of 5.11 ± 0.09 days. Ultraviolet images during 13–14 June 2022 suggest that the discontinuity may have manifested at the top of the clouds during ∼21 h as a result of an altitude change in the critical level for this wave, due to slower zonal winds.
• Strong Relationship between Eye Radius and Radius of Maximum Wind of Tropical Cyclones
  Taiga Tsukada; Takeshi Horinouchi
  Monthly Weather Review, 151, 2, 569, 588, American Meteorological Society, Feb. 2023, [Peer-reviewed], [Last author]
  Scientific journal, Abstract
  
  Estimation of the radius of maximum wind (RMW) of tropical cyclone (TC) is helpful for the disaster prevention and mitigation. If RMWs are estimated from infrared (IR) imagery taken by geostationary meteorological satellites, their estimation is available densely in time, regardless of the ocean basin. Kossin et al. showed that when TCs have clear eyes, the eye radii estimated from IR images have a high correlation with the RMW estimated from aircraft reconnaissance. The regression of the former onto that latter was shown to have a mean absolute error (MAE) of 4.7 km. We revisit the IR-based RMW estimation by using C-band synthetic aperture radar (SAR) sea surface wind estimates. The criteria for selecting clear-eye cases are simplified. The MAE of the Kossin et al. method is found to be smaller than previously suggested: 3.1 km when the proposed relation is used and 2.7 km when the regression is revised with the SAR-measured RMWs. We further propose an improvement of the IR-based method to estimate the eye radii. The resultant MAE is shown to be 1.7 km, which indicates that the IR-based RMW estimation is more accurate than has been suggested. A strong correlation between eyewall slope and eye size is confirmed. We also investigated cloud features in the eye that may be closely related to RMW and wind structure around RMW. Potential applications of highly accurate RMW estimation are discussed.
  
  Significance Statement
  
  The radius of maximum wind (RMW) of tropical cyclone (TC) is an important factor for TC intensity estimation and disaster prevention. A previous study suggested that the RMWs of TCs with clear eyes can be estimated from geostationary satellite images at a mean absolute error (MAE) of 4.7 km. Here we improved the method, reducing the MAE by more than one-half. Since the method does not require aircraft or satellite in low Earth orbit, it helps TC monitoring at high frequency. The method can also improve initialization of models used to predict TC hazards and further our physical understanding and the climatology of the wind structures near the centers of TCs.
• Gigantic Vortices From Barotropic Instability Observed in the Atmosphere of Venus
  Takeshi Horinouchi; Takehiko Satoh; Javier Peralta
  Geophysical Research Letters, 50, 2, American Geophysical Union ({AGU}), 28 Jan. 2023, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal
• Bimodal Distribution of Precipitation Found in the Multimodel Climate Prediction over Central Japan in Winter
  Naoki Sato; Takeshi Horinouchi; Yoshio Kawatani
  SOLA, 19, 78, 85, Meteorological Society of Japan, 2023, [Peer-reviewed]
  Scientific journal
• Gross Assessment of the Dynamical Impact of Numerous Power-Generating Sailing Ships on the Atmosphere and Evaluation of the Impact on Tropical Cyclones
  Takeshi Horinouchi; Taiga Mitsuyuki
  SOLA, 19, 57, 62, Meteorological Society of Japan, 2023, [Peer-reviewed], [Lead author, Corresponding author]
  Scientific journal
• Stationary and Transient Asymmetric Features in Tropical Cyclone Eye with Wavenumber-one Instability: Case Study for Typhoon Haishen (2020) with Atmospheric Motion Vectors from 30-second Imaging
  Takeshi Horinouchi; Satoki Tsujino; Masahiro Hayashi; Udai Shimada; Wataru Yanase; Akiyoshi Wada; Hiroyuki Yamada
  Monthly Weather Review, 151, 1, 253, 273, American Meteorological Society, 25 Oct. 2022, [Peer-reviewed], [Lead author, Corresponding author]
  Scientific journal, Abstract
  
  Dynamics of low-level flows in the eye of Typhoon Haishen (2020) in its late phase of intensification are investigated with a special rapid-scan observation of the Himawari-8 geosynchronous satellite conducted every 30 seconds. This is accomplished by deriving storm-relative atmospheric motion vectors at an unprecedentedly high spatiotemporal resolution by tracking clouds across five consecutive visible-light reflectivity. The overall low-level circulation center was situated several kilometers away from the storm center defined in terms of the inner edge of the lower part of eyewall clouds. The shift direction is rearward the storm translation, consistently with a numerical study of tropical cyclone (TC) boundary layer. Over the analysis period of 10 hours, azimuthal-mean tangential wind around this center was increased at each radius within the eye, and the rotational angular velocity was nearly homogenized. The instantaneous low-level circulation center is found to orbit around the overall circulation center at distances around 5 km. Its orbital angular speed was close to the maximum angular speed of azimuthal-mean tangential winds. This rotating transient disturbance is found to transport angular momentum inward, which explains the tangential wind increase and the angular velocity homogenization in the eye. These features are consistent with an algebraically growing wavenumber-1 barotropic instability, whose impact on TC structures has not been explored. This instability enhances wavenuber-1 asymmetry in ring shaped vorticity, which can be induced by various processes such as translation, environmental shear, and exponential barotropic instability. Therefore, it may appear broadly in TCs to affect wind distribution in their eyes.
• Thermal tides reproduced in the assimilation results of horizontal winds obtained from Akatsuki UVI observations
  Yukiko Fujisawa; Shin-ya Murakami; Norihiko Sugimoto; Masahiro Takagi; Takeshi Imamura; Takeshi Horinouchi; George L. Hashimoto; Masaki Ishiwatari; Takeshi Enomoto; Takemasa Miyoshi; Hiroki Kashimura; Yoshi-Yuki Hayashi
  23 Sep. 2022
• The first assimilation of Akatsuki single-layer winds and its validation with Venusian atmospheric waves excited by solar heating
  Yukiko Fujisawa; Shin-ya Murakami; Norihiko Sugimoto; Masahiro Takagi; Takeshi Imamura; Takeshi Horinouchi; George L. Hashimoto; Masaki Ishiwatari; Takeshi Enomoto; Takemasa Miyoshi; Hiroki Kashimura; Yoshi-Yuki Hayashi
  Scientific Reports, 12, 1, Springer Science and Business Media LLC, 26 Aug. 2022, [Peer-reviewed]
  Scientific journal, Abstract
  
  The planetary missions including the Venus Climate Orbiter ‘Akatsuki’ provide new information on various atmospheric phenomena. Nevertheless, it is difficult to elucidate their three-dimensional structures globally and continuously only from observations because satellite observations are considerably limited in time and space. We constructed the first ‘objective analysis’ of Venus’ atmosphere by assimilating cloud-top horizontal winds on the dayside from the equator to mid-latitudes, which is frequently obtained from Akatsuki's Ultraviolet Imager (UVI). The three-dimensional structures of thermal tides, found recently to play a crucial role in maintaining the super rotation, are greatly improved by the data assimilation. This result is confirmed by comparison with Akatsuki's temperature observations. The momentum transport caused by the thermal tides and other disturbances are also modified by the wind assimilation and agrees well with those estimated from the UVI observations. The assimilated dataset is reliable and will be open to the public along with the Akatsuki observations for further investigation of Venus’ atmospheric phenomena.
• Inter-model variability of the CMIP5 future projection of Baiu, Meiyu, and Changma precipitation
  Takeshi Horinouchi; Yoshio Kawatani; Naoki Sato
  Climate Dynamics, Springer Science and Business Media {LLC}, 26 Jul. 2022, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal, Abstract
  
  Many studies have suggested that mean precipitation associated with the East Asian Summer Monsoon (EASM) will be increased by the ongoing global warming, but its quantitative projection by climate models has large variability, with some models suggesting even decreases. We investigate the inter-model variability of projected centennial changes of the EASM separately for Baiu over Japan, Meiyu over eastern China, and Changma over Korea by using monthly-mean model outputs provided by the Coupled Model Intercomparison Project Phase 5 (CMIP5) project. Results with the Representative Concentration Pathway 4.5 and 8.5 scenarios (RCP4.5 and RCP8.5) are consolidated by normalizing with the global-mean near-surface air temperature changes. For all the three EASM land regions, inter-model differences in the mean precipitation changes are positively correlated with the southerly moisture flux changes to the south of the regions. The correlation is highest in June among the June-to-August months, whose reason may be because precipitation in early summer relies on large-scale southerly moisture transport. These changes are localized and nearly independent among the three regions where Baiu, Meiyu and Changma occur. The low-level southerly change to the south of Japan, which affects the Baiu precipitation change, is positively correlated with upper-tropospheric meridional wind to its north; it further exhibits a stationary Rossby-wave feature associated with the Silk-Road teleconnection. This study suggests that future changes in the EASM mean precipitation depend on circulation changes and more-or-less localized.
• Contributions of the Large-Scale Environment to the Typhoon Genesis of Faxai (2019)
  Hironori FUDEYASU; Udai SHIMADA; Yoshinori OIKAWA; Hisaki EITO; Akiyoshi WADA; Ryuji YOSHIDA; Takeshi HORINOUCHI
  Journal of the Meteorological Society of Japan. Ser. II, 100, 4, 617, 630, Meteorological Society of Japan, 2022, [Peer-reviewed]
  Scientific journal
• Storylines of Projected Climate Changes around Japan Associated with Upper Troposphere and Stratosphere Responses
  Yoshio Kawatani; Takeshi Horinouchi; Naoki Sato
  SOLA, 18, 122, 128, Meteorological Society of Japan, 2022, [Peer-reviewed]
  English, Scientific journal
• Multiple Dynamics of Precipitation Concentrated on the North Side of Typhoon Hagibis (2019) during Extratropical Transition
  Wataru YANASE; Kentaro ARAKI; Akiyoshi WADA; Udai SHIMADA; Masahiro HAYASHI; Takeshi HORINOUCHI
  Journal of the Meteorological Society of Japan. Ser. II, 100, 5, 783, 805, Meteorological Society of Japan, 2022, [Peer-reviewed], [Last author]
  Scientific journal
• The nightside cloud-top circulation of the atmosphere of Venus
  Kiichi Fukuya; Takeshi Imamura; Makoto Taguchi; Tetsuya Fukuhara; Toru Kouyama; Takeshi Horinouchi; Javier Peralta; Masahiko Futaguchi; Takeru Yamada; Takao M. Sato; Atsushi Yamazaki; Shin-ya Murakami; Takehiko Satoh; Masahiro Takagi; Masato Nakamura
  Nature, 595, 7868, 511, 515, Springer Science and Business Media {LLC}, 22 Jul. 2021, [Peer-reviewed]
  English, Scientific journal
• Robust Asymmetry of the Future Arctic Polar Vortex Is Driven by Tropical Pacific Warming
  Shinji Matsumura; Koji Yamazaki; Takeshi Horinouchi
  Geophysical Research Letters, 48, 11, American Geophysical Union ({AGU}), 16 Jun. 2021, [Peer-reviewed], [Last author]
  English, Scientific journal
• Inner‐Core Wind Field in a Concentric Eyewall Replacement of Typhoon Trami (2018): A Quantitative Analysis Based on the Himawari‐8 Satellite
  S. Tsujino; T. Horinouchi; T. Tsukada; H.-C. Kuo; H. Yamada; K. Tsuboki
  Journal of Geophysical Research: Atmospheres, 126, 7, American Geophysical Union ({AGU}), 16 Apr. 2021, [Peer-reviewed]
  English, Scientific journal
• Venus night-side photometry with “cleaned” Akatsuki/IR2 data: Aerosol properties and variations of carbon monoxide
  Takehiko Satoh; Choon Wei Vun; Masafumi Kimata; Takeshi Horinouchi; Takao M. Sato
  Icarus, 355, 114134, 114134, Elsevier {BV}, Feb. 2021, [Peer-reviewed]
  English, Scientific journal
• Moisture Supply, Jet, and Silk-Road Wave Train Associated with the Prolonged Heavy Rainfall in Kyushu, Japan in Early July 2020
  Takeshi Horinouchi; Yu Kosaka; Hiroshi Nakamigawa; Hisashi Nakamura; Norihisa Fujikawa; Yukari N. Takayabu
  SOLA, 17B, Special_Edition, 1, 8, Meteorological Society of Japan, 2021, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal
• A Long‐Lived Sharp Disruption on the Lower Clouds of Venus
  Takeshi Horinouchi
  Geophysical Research Letters, 47, 11, American Geophysical Union (AGU), 16 Jun. 2020, [Peer-reviewed]
  English, Scientific journal
• Estimation of the Tangential Winds and Asymmetric Structures in Typhoon Inner Core Region Using Himawari‐8
  Takeshi Horinouchi
  Geophysical Research Letters, 47, 11, American Geophysical Union (AGU), 16 Jun. 2020, [Peer-reviewed], [Last author]
  English, Scientific journal
• How waves and turbulence maintain the super-rotation of Venus' atmosphere.
  Takeshi Horinouchi
  Science (New York, N.Y.), 368, 6489, 405, 409, American Association for the Advancement of Science (AAAS), 01 Apr. 2020, [Peer-reviewed], [Lead author, Corresponding author]
  Scientific journal, Venus has a thick atmosphere that rotates 60 times as fast as the surface, a phenomenon known as super-rotation. We use data obtained from the orbiting Akatsuki spacecraft to investigate how the super-rotation is maintained in the cloud layer, where the rotation speed is highest. A thermally induced latitudinal-vertical circulation acts to homogenize the distribution of the angular momentum around the rotational axis. Maintaining the super-rotation requires this to be counteracted by atmospheric waves and turbulence. Among those effects, thermal tides transport the angular momentum, which maintains the rotation peak, near the cloud top at low latitudes. Other planetary-scale waves and large-scale turbulence act in the opposite direction. We suggest that hydrodynamic instabilities adjust the angular-momentum distribution at mid-latitudes.
• Convective Bursts With Gravity Waves in Tropical Cyclones: Case Study With the Himawari‐8 Satellite and Idealized Numerical Study
  Takeshi Horinouchi
  Geophysical Research Letters, 47, 3, American Geophysical Union (AGU), 16 Feb. 2020, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal
• New cloud morphologies discovered on the Venus's night during Akatsuki
  J. Peralta; A. Sánchez-Lavega; T. Horinouchi; K. McGouldrick; I. Garate-Lopez; E.F. Young; M.A. Bullock; Y.J. Lee; T. Imamura; T. Satoh; S.S. Limaye
  Icarus, 333, 177, 182, Elsevier BV, Nov. 2019, [Peer-reviewed]
  Scientific journal
• Planetary‐Scale Variations in Winds and UV Brightness at the Venusian Cloud Top: Periodicity and Temporal Evolution
  Masataka Imai; Toru Kouyama; Yukihiro Takahashi; Atsushi Yamazaki; Shigeto Watanabe; Manabu Yamada; Takeshi Imamura; Takehiko Satoh; Masato Nakamura; Shin‐ya Murakami; Kazunori Ogohara; Takeshi Horinouchi
  Journal of Geophysical Research: Planets, American Geophysical Union ({AGU}), 31 Oct. 2019, [Peer-reviewed], [Last author]
  Scientific journal
• Global Structure of Thermal Tides in the Upper Cloud Layer of Venus Revealed by LIR on Board Akatsuki
  T. Kouyama; M. Taguchi; T. Fukuhara; T. Imamura; T. Horinouchi; T. M. Sato; S. Murakami; G. L. Hashimoto; Y. J. Lee; M. Futaguchi; T. Yamada; M. Akiba; T. Satoh; M. Nakamura
  Geophysical Research Letters, 46, 16, 9457, 9465, American Geophysical Union ({AGU}), 28 Aug. 2019, [Peer-reviewed]
  Scientific journal
• Long-term Variations of Venus’s 365 nm Albedo Observed by Venus Express, Akatsuki, MESSENGER, and the Hubble Space Telescope
  Yeon Joo Lee; Kandis-Lea Jessup; Santiago Perez-Hoyos; Dmitrij V. Titov; Sebastien Lebonnois; Javier Peralta; Takeshi Horinouchi; Takeshi Imamura; Sanjay Limaye; Emmanuel Marcq; Masahiro Takagi; Atsushi Yamazaki; Manabu Yamada; Shigeto Watanabe; Shin-ya Murakami; Kazunori Ogohara; William M. McClintock; Gregory Holsclaw; Anthony Roman
  The Astronomical Journal, 158, 3, 126, 126, American Astronomical Society, 26 Aug. 2019, [Peer-reviewed]
  Scientific journal, Abstract
  
  An unknown absorber near the cloud-top level of Venus generates a broad absorption feature from the ultraviolet (UV) to visible, peaking around 360 nm, and therefore plays a critical role in the solar energy absorption. We present a quantitative study of the variability of the cloud albedo at 365 nm and its impact on Venus’s solar heating rates based on an analysis of Venus Express and Akatsuki UV images and Hubble Space Telescope and MESSENGER UV spectral data; in this analysis, the calibration correction factor of the UV images of Venus Express (Venus Monitoring Camera) is updated relative to the Hubble and MESSENGER albedo measurements. Our results indicate that the 365 nm albedo varied by a factor of 2 from 2006 to 2017 over the entire planet, producing a 25%–40% change in the low-latitude solar heating rate according to our radiative transfer calculations. Thus, the cloud-top level atmosphere should have experienced considerable solar heating variations over this period. Our global circulation model calculations show that this variable solar heating rate may explain the observed variations of zonal wind from 2006 to 2017. Overlaps in the timescale of the long-term UV albedo and the solar activity variations make it plausible that solar extreme UV intensity and cosmic-ray variations influenced the observed albedo trends. The albedo variations might also be linked with temporal variations of the upper cloud SO₂ gas abundance, which affects the H₂SO₄–H₂O aerosol formation.
• Stationary Features at the Cloud Top of Venus Observed by Ultraviolet Imager Onboard Akatsuki
  Takehiko Kitahara; Takeshi Imamura; Takao M. Sato; Atsushi Yamazaki; Yeon Joo Lee; Manabu Yamada; Shigeto Watanabe; Makoto Taguchi; Tetsuya Fukuhara; Toru Kouyama; Shin‐ya Murakami; George L. Hashimoto; Kazunori Ogohara; Hiroki Kashimura; Takeshi Horinouchi; Masahiro Takagi
  Journal of Geophysical Research: Planets, American Geophysical Union ({AGU}), 15 May 2019, [Peer-reviewed]
  Scientific journal
• Contrasting Responses of Midlatitude Jets to the North Pacific and North Atlantic Warming
  Shinji Matsumura; Satoaki Ueki; Takeshi Horinouchi
  Geophysical Research Letters, 46, 7, 3973, 3981, 16 Apr. 2019, [Peer-reviewed], [Last author]
  English, Scientific journal
• Jet–Precipitation Relation and Future Change of the Mei-Yu–Baiu Rainband and Subtropical Jet in CMIP5 Coupled GCM Simulations
  Takeshi Horinouchi; Shinji Matsumura; Tomoaki Ose; Yukari N. Takayabu
  Journal of Climate, 32, 8, 2247, 2259, 15 Apr. 2019, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal
• Solar-locked and geographical atmospheric structures inferred from a Venus general circulation model with radiative transfer
  Masaru Yamamoto; Kohei Ikeda; Masaaki Takahashi; Takeshi Horinouchi
  Icarus, 321, 232, 250, Mar. 2019, [Peer-reviewed]
  English, Scientific journal
• Ultraviolet imager on Venus orbiter Akatsuki and its initial results
  Atsushi Yamazaki; Manabu Yamada; Yeon Joo Lee; Shigeto Watanabe; Takeshi Horinouchi; Shin-ya Murakami; Toru Kouyama; Kazunori Ogohara; Takeshi Imamura; Takao M. Sato; Yukio Yamamoto; Tetsuya Fukuhara; Hiroki Ando; Ko-ichiro Sugiyama; Seiko Takagi; Hiroki Kashimura; Shoko Ohtsuki; Naru Hirata; George L. Hashimoto; Makoto Suzuki; Chikako Hirose; Munetaka Ueno; Takehiko Satoh; Takumi Abe; Nobuaki Ishii; Masato Nakamura
  Earth, Planets and Space, 70, 1, 01 Dec. 2018, [Peer-reviewed]
  English, Scientific journal
• Nightside Winds at the Lower Clouds of Venus with Akatsuki/IR2: Longitudinal, Local Time, and Decadal Variations from Comparison with Previous Measurements
  Javier Peralta; Keishiro Muto; Ricardo Hueso; Takeshi Horinouchi; Agust{\'{\i; S{\'{a } }nchez-Lavega; Shin-ya Murakami; Pedro Machado; Eliot F. Young; Yeon Joo Lee; Toru Kouyama; Hideo Sagawa; Kevin McGouldrick; Takehiko Satoh; Takeshi Imamura; Sanjay S. Limaye; Takao M. Sato; Kazunori Ogohara; Masato Nakamura; David Luz
  The Astrophysical Journal Supplement Series, 239, 2, 29, 29, American Astronomical Society, Dec. 2018, [Peer-reviewed]
  Scientific journal
• Mean winds at the cloud top of Venus obtained from two-wavelength UV imaging by Akatsuki
  Takeshi Horinouchi; Toru Kouyama; Yeon Joo Lee; Shin-ya Murakami; Kazunori Ogohara; Masahiro Takagi; Takeshi Imamura; Kensuke Nakajima; Javier Peralta; Atsushi Yamazaki; Manabu Yamada; Shigeto Watanabe
  Earth, Planets and Space, 70, 1, 01 Dec. 2018, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal
• Reintensification and Eyewall Formation in Strong Shear: A Case Study of Typhoon Noul (2015)
  Shimada, Udai; Horinouchi, Takeshi
  Monthly Weather Review, 146, 9, 2799, 2817, 2018, [Peer-reviewed]
  Scientific journal
• Venus Looks Different at Different Wavelengths: Morphology of the Global Day and Night Cloud Cover at Different Wavelengths from Akatsuki Cameras
  Sanjay S. Limaye; Shigeto Watanabe; Atsushi Yamazaki; Manabu Yamada; Takehiko Satoh; Masato Nakamura; Makoto Taguchi; Tetsuya Fukuhara; Takeshi Imamura; Toru Kouyama; Yeon Joo Lee; Takeshi Horinouchi; Javier Peralta; Naomoto Iwagami; George L. Hashimoto; Seiko Takagi; Shoko Ohtsuki; Shin-ya Murakami; Yukio Yamamoto; Kazunori Ogohara; Hiroki Ando; Ko-ichiro Sugiyama; Nobuaki Ishii; Takumi Abe; Chikako Hirose; Makoto Suzuki; Naru Hirata; Eliot F. Young; Adriana C. Ocampo
  Earth, Planets and Space, 70, 1, 2018, [Peer-reviewed]
  English, Scientific journal
• Topographical and Local Time Dependence of Large Stationary Gravity Waves Observed at the Cloud Top of Venus
  T. Kouyama; T. Imamura; M. Taguchi; T. Fukuhara; T. M. Sato; A. Yamazaki; M. Futaguchi; S. Murakami; G. L. Hashimoto; M. Ueno; N. Iwagami; S. Takagi; M. Takagi; K. Ogohara; H. Kashimura; T. Horinouchi; N. Sato; M. Yamada; Y. Yamamoto; S. Ohtsuki; K. Sugiyama; H. Ando; M. Takamura; T. Yamada; T. Satoh; M. Nakamura
  Geophysical Research Letters, 44, 24, 12, 105, 28 Dec. 2017, [Peer-reviewed]
  English, Scientific journal
• Performance of Akatsuki/IR2 in Venus orbit: the first year
  Takehiko Satoh; Takao M. Sato; Masato Nakamura; Yasumasa Kasaba; Munetaka Ueno; Makoto Suzuki; George L. Hashimoto; Takeshi Horinouchi; Takeshi Imamura; Atsushi Yamazaki; Takayuki Enomoto; Yuri Sakurai; Kosuke Takami; Kenta Sawai; Takashi Nakakushi; Takumi Abe; Nobuaki Ishii; Chikako Hirose; Naru Hirata; Manabu Yamada; Shin-ya Murakami; Yukio Yamamoto; Tetsuya Fukuhara; Kazunori Ogohara; Hiroki Ando; Ko-ichiro Sugiyama; Hiroki Kashimura; Shoko Ohtsuki
  EARTH PLANETS AND SPACE, 69, Nov. 2017, [Peer-reviewed]
  English, Scientific journal
• Precipitation Characteristics over East Asia in Early Summer: Effects of the Subtropical Jet and Lower-Tropospheric Convective Instability
  Chie Yokoyama; Yukari N. Takayabu; Takeshi Horinouchi
  JOURNAL OF CLIMATE, 30, 20, 8127, 8147, Oct. 2017, [Peer-reviewed]
  English, Scientific journal
• Equatorial jet in the lower to middle cloud layer of Venus revealed by Akatsuki
  Takeshi Horinouchi; Shin-ya Murakami; Takehiko Satoh; Javier Peralta; Kazunori Ogohara; Toru Kouyama; Takeshi Imamura; Hiroki Kashimura; Sanjay S. Limaye; Kevin McGouldrick; Masato Nakamura; Takao M. Sato; Ko-ichiro Sugiyama; Masahiro Takagi; Shigeto Watanabe; Manabu Yamada; Atsushi Yamazaki; Eliot F. Young
  Nature Geoscience, 10, 9, 646, 651, Aug. 2017, [Peer-reviewed]
  Scientific journal
• Image velocimetry for clouds with relaxation labeling based on deformation consistency
  Takeshi Horinouchi; Shin-ya Murakami; Toru Kouyama; Kazunori Ogohara; Atsushi Yamazaki; Manabu Yamada; Shigeto Watanabe
  MEASUREMENT SCIENCE AND TECHNOLOGY, 28, 8, Aug. 2017, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal
• Venus's winds and temperatures during the MESSENGER's flyby: An approximation to a three-dimensional instantaneous state of the atmosphere
  J. Peralta; Y. J. Lee; R. Hueso; R. T. Clancy; B. J. Sandor; A. Sanchez-Lavega; E. Lellouch; M. Rengel; P. Machado; M. Omino; A. Piccialli; T. Imamura; T. Horinouchi; S. Murakami; K. Ogohara; D. Luz; D. Peach
  GEOPHYSICAL RESEARCH LETTERS, 44, 8, 3907, 3915, Apr. 2017, [Peer-reviewed]
  English, Scientific journal
• Meandering Subtropical Jet and Precipitation over Summertime East Asia and the Northwestern Pacific
  Takeshi Horinouchi; Ayumu Hayashi
  JOURNAL OF THE ATMOSPHERIC SCIENCES, 74, 4, 1233, 1247, Apr. 2017, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal
• Large stationary gravity wave in the atmosphere of Venus
  Tetsuya Fukuhara; Masahiko Futaguchi; George L. Hashimoto; Takeshi Horinouchi; Takeshi Imamura; Naomoto Iwagaimi; Toru Kouyama; Shin-ya Murakami; Masato Nakamura; Kazunori Ogohara; Mitsuteru Sato; Takao M. Sato; Makoto Suzuki; Makoto Taguchi; Seiko Takagi; Munetaka Ueno; Shigeto Watanabe; Manabu Yamada; Atsushi Yamazaki
  NATURE GEOSCIENCE, 10, 2, 85, +, Feb. 2017, [Peer-reviewed]
  English, Scientific journal
• Equatorial jet in the lower to middle cloud layer of Venus revealed by Akatsuki (vol 10, pg 646, 2017)
  Horinouchi T; Murakami S. Y; Satoh T; Peralta J; Ogohara K; Kouyama T; Imamura T; Kashimura H; Limaye S. S; McGouldrick K; Nakamura M; Sato T. M; Sugiyama K. I; Takagi M; Watanabe S; Yamada M; Yamazaki A; Young E. F
  Nature Geoscience, 10, 10, 798, 2017, [Peer-reviewed]
• Equatorial jet in the lower to middle cloud layer of Venus revealed by Akatsuki
  Horinouchi, Takeshi; Murakami, Shin-ya; Satoh, Takehiko; Peralta, Javier; Ogohara, Kazunori; Kouyama, Toru; Imamura, Takeshi; Kashimura, Hiroki; Limaye; Sanjay S.; McGouldrick, Kevin; Nakamura, Masato; Sato; Takao M.; Sugiyama; Ko-ichiro; Takagi; Masahiro a; Watanabe, Shigeto; Yamada, Manabu; Yamazaki, Atsushi; Young; Eliot F.
  Nature Geoscience, 10, 9, 646, +, 2017, [Peer-reviewed], [Lead author, Corresponding author]
  Scientific journal
• VENUS CLOUD MORPHOLOGY AND MOTIONS FROM GROUND- BASED IMAGES AT THE TIME OF THE AKATSUKI ORBIT INSERTION
  A. Sanchez-Lavega; J. Peralta; J. M. Gomez-Forrellad; R. Hueso; S. Perez-Hoyos; I. Mendikoa; J. F. Rojas; T. Horinouchi; Y. J. Lee; S. Watanabe
  ASTROPHYSICAL JOURNAL LETTERS, 833, 1, Dec. 2016, [Peer-reviewed]
  English, Scientific journal
• Pacific Ocean decadal forcing of long-term changes in the western Pacific subtropical high
  Shinji Matsumura; Takeshi Horinouchi
  SCIENTIFIC REPORTS, 6, Nov. 2016, [Peer-reviewed]
  English, Scientific journal
• Improved automatic estimation of winds at the cloud top of Venus using superposition of cross-correlation surfaces
  Shinichi Ikegawa; Takeshi Horinouchi
  ICARUS, 271, 98, 119, Jun. 2016, [Peer-reviewed]
  English, Scientific journal
• AKATSUKI returns to Venus
  Masato Nakamura; Takeshi Imamura; Nobuaki Ishii; Takumi Abe; Yasuhiro Kawakatsu; Chikako Hirose; Takehiko Satoh; Makoto Suzuki; Munetaka Ueno; Atsushi Yamazaki; Naomoto Iwagami; Shigeto Watanabe; Makoto Taguchi; Tetsuya Fukuhara; Yukihiro Takahashi; Manabu Yamada; Masataka Imai; Shoko Ohtsuki; Kazunori Uemizu; George L. Hashimoto; Masahiro Takagi; Yoshihisa Matsuda; Kazunori Ogohara; Naoki Sato; Yasumasa Kasaba; Toru Kouyama; Naru Hirata; Ryosuke Nakamura; Yukio Yamamoto; Takeshi Horinouchi; Masaru Yamamoto; Yoshi-Yuki Hayashi; Hiroki Kashimura; Ko-ichiro Sugiyama; Takeshi Sakanoi; Hiroki Ando; Shin-ya Murakami; Takao M. Sato; Seiko Takagi; Kensuke Nakajima; Javier Peralta; Yeon Joo Lee; Junichi Nakatsuka; Tsutomu Ichikawa; Kozaburo Inoue; Tomoaki Toda; Hiroyuki Toyota; Sumitaka Tachikawa; Shinichiro Narita; Tomoko Hayashiyama; Akiko Hasegawa; Yukio Kamata
  EARTH PLANETS AND SPACE, 68, May 2016, [Peer-reviewed]
  English, Scientific journal
• Response of the Baiu Rainband to Northwest Pacific SST Anomalies and Its Impact on Atmospheric Circulation
  Shinji Matsumura; Takeshi Horinouchi; Shiori Sugimoto; Tomonori Sato
  JOURNAL OF CLIMATE, 29, 8, 3075, 3093, Apr. 2016, [Peer-reviewed]
  English, Scientific journal
• Influence of Upper Tropospheric Disturbances on the Synoptic Variability of Precipitation and Moisture Transport over Summertime East Asia and the Northwestern Pacific
  Takeshi Horinouchi
  JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN, 92, 6, 519, 541, 2014, [Peer-reviewed], [Lead author, Last author, Corresponding author]
  English, Scientific journal
• Modulation of seasonal precipitation over the tropical western/central pacific by convectively coupled mixed rossby-gravity waves
  Takeshi Horinouchi
  Journal of the Atmospheric Sciences, 70, 2, 600, 606, Feb. 2013, [Peer-reviewed], [Lead author, Last author, Corresponding author]
  English, Scientific journal
• An experimental data handling system for ensemble numerical weather predictions using aweb-based data server and analysis tool "Gfdnavi"
  Shigenori Otsuka; Seiya Nishizawa; Takeshi Horinouchi; Shigeo Yoden
  Journal of Disaster Research, 8, 1, 48, 56, Fuji Technology Press, 2013, [Peer-reviewed]
  English, Scientific journal
• Gfdnavi: A tool to analyze, visualize, and share meteorological data, and its application to the output of ensemble predictions
  S. Otsuka; S. Nisizawa; T. Horinouchi; S. Yoden
  Journal of Disaster Research, 8, 1, 135, 136, 2013, [Peer-reviewed]
  English
• Low Cloud Modulation by Synoptic Waves over the Eastern Tropical Pacific
  Tatsuya Terao; Takeshi Horinouchi
  JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN, 90, 6, 947, 958, Dec. 2012, [Peer-reviewed], [Last author]
  English, Scientific journal
• Moist Hadley Circulation: Possible Role of Wave-onvection Coupling in Aquaplanet Experiments
  Takeshi Horinouchi
  JOURNAL OF THE ATMOSPHERIC SCIENCES, 69, 3, 891, 907, Mar. 2012, [Peer-reviewed], [Lead author, Last author, Corresponding author]
  English, Scientific journal
• "Gtool5": a Fortran90 library of input/output interfaces for self-descriptive multi-dimensional numerical data
  M. Ishiwatari; E. Toyoda; Y. Morikawa; S. Takehiro; Y. Sasaki; S. Nishizawa; M. Odaka; N. Otobe; Y. O. Takahashi; K. Nakajima; T. Horinouchi; M. Shiotani; Y.-Y. Hayashi; Gtool development group
  Geosci. Model Dev., 5, 2, 449, 455, 2012, [Peer-reviewed]
  Scientific journal
• Overview of Venus orbiter, Akatsuki
  M. Nakamura; T. Imamura; N. Ishii; T. Abe; T. Satoh; M. Suzuki; M. Ueno; A. Yamazaki; N. Iwagami; S. Watanabe; M. Taguchi; T. Fukuhara; Y. Takahashi; M. Yamada; N. Hoshino; S. Ohtsuki; K. Uemizu; G. L. Hashimoto; M. Takagi; Y. Matsuda; K. Ogohara; N. Sato; Y. Kasaba; T. Kouyama; N. Hirata; R. Nakamura; Y. Yamamoto; N. Okada; T. Horinouchi; M. Yamamoto; Y. Hayashi
  EARTH PLANETS AND SPACE, 63, 5, 443, 457, 2011, [Peer-reviewed]
  English, Scientific journal
• Gfdnavi, Web-Based Data and Knowledge Server Software for Geophysical Fluid Sciences, Part I: Rationales, Stand-Alone Features, and Supporting Knowledge Documentation Linked to Data
  Takeshi Horinouchi; Seiya Nishizawa; Chiemi Watanabe; Akinori Tomobayashi; Shigenori Otsuka; Tsuyoshi Koshiro; Yoshi-Yuki Hayashi
  DATABASE SYSTEMS FOR ADVANCED APPLICATIONS, 6193, 93, +, 2010, [Peer-reviewed]
  English, International conference proceedings
• Gfdnavi, Web-Based Data and Knowledge Server Software for Geophysical Fluid Sciences, Part II: RESTful Web Services and Object-Oriented Programming Interface
  Seiya Nishizawa; Takeshi Horinouchi; Chiemi Watanabe; Yuka Isamoto; Akinori Tomobayashi; Shigenori Otsuka
  DATABASE SYSTEMS FOR ADVANCED APPLICATIONS, 6193, 105, +, 2010, [Peer-reviewed]
  English, International conference proceedings
• Spatial structures and statistics of atmospheric gravity waves derived using a heuristic vertical cross-section extraction from COSMIC GPS radio occultation data
  Takeshi Horinouchi; Toshitaka Tsuda
  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 114, Aug. 2009, [Peer-reviewed]
  English, Scientific journal
• Spatial structures and statistics of atmospheric gravity waves derived using a heuristic vertical cross-section extraction from COSMIC GPS radio occultation data
  Takeshi Horinouchi; Toshitaka Tsuda
  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 114, Aug. 2009, [Peer-reviewed]
  English, Scientific journal
• Gravity waves in the upper atmosphere of Venus revealed by CO2nonlocal thermodynamic equilibrium emissions
  R. F. Garcia; P. Drossart; G. Piccioni; M. López-Valverde; G. Occhipinti
  Journal of Geophysical Research, 114, American Geophysical Union (AGU), 17 Mar. 2009, [Peer-reviewed]
  Scientific journal
• Spatial structures and statistics of atmospheric gravity waves derived using a heuristic vertical cross-section extraction from COSMIC GPS radio occultation data
  Takeshi Horinouchi; Toshitaka Tsuda
  Journal of Geophysical Research Atmospheres, 114, 16, Blackwell Publishing Ltd, 2009, [Peer-reviewed]
  English, Scientific journal
• A numerical study of upward-propagating gravity waves in two different MJO phases
  Takeshi Horinouchi
  GEOPHYSICAL RESEARCH LETTERS, 35, 17, Sep. 2008, [Peer-reviewed]
  English, Scientific journal
• The 5-8-day Kelvin and Rossby waves in the tropics as revealed by ground and satellite-based observations
  S. Sridharan; T. Tsuda; T. Nakamura; T. Horinouchi
  JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN, 86, 1, 43, 55, Feb. 2008, [Peer-reviewed]
  English, Scientific journal
• An interactive 3D visualization model by live streaming for remote scientific visualization
  Eriko Touma; Satomi Hara; Mari Kurumi; Yuri Shirakawa; Chisato Ishikawa; Masami Takata; Takeshi Horinouchi; Kazuki Joe
  GRAPP 2008: PROCEEDINGS OF THE THIRD INTERNATIONAL CONFERENCE ON COMPUTER GRAPHICS THEORY AND APPLICATIONS, 409, 414, 2008, [Peer-reviewed]
  English, International conference proceedings
• Vertical wind observation in the tropical upper troposphere by VHF wind profiler: A case study
  Masayuki K. Yamamoto; Noriyuki Nishi; Takeshi Horinouchi; Masanori Niwano; Shoichiro Fukao
  RADIO SCIENCE, 42, 3, May 2007, [Peer-reviewed]
  English, Scientific journal
• An intense gravity wave near the mesopause region observed by a Fabry-Perot interferometer and an airglow imager
  K. Shiokawa; S. Suzuki; Y. Otsuka; T. Ogawa; T. Nakamura; T. Horinouchi
  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 112, D7, Apr. 2007, [Peer-reviewed]
  English, Scientific journal
• 地球流体データベース・解析・可視化のための新しいサーバ兼デスクトップツール Gfdnavi の開発
  堀之内 武; 西澤 誠也; 渡辺 知恵美; 森川 靖大; 神代 剛; 石渡 正樹; HAYASHI YOSHIYUKI; 塩谷雅人
  電子情報通信学会第18回データ工学ワークショップ(DEWS2007)論文集, E1-8 (pp.8), 2007, [Peer-reviewed]
  Japanese, Scientific journal
• RDoc を用いた数値モデルのドキュメント生成
  森川 靖大; 石渡 正樹; 堀之内 武; 小高 正嗣; HAYASHI YOSHIYUKI
  天気, 54, 185-190, 238, 238, 日本気象学会, 2007
  Japanese, Scientific journal
• Momentum flux spectrum of convectively forced gravity waves: Can diabatic forcing be a proxy for convective forcing?
  HY Chun; IS Song; T Horinouchi
  JOURNAL OF THE ATMOSPHERIC SCIENCES, 62, 11, 4113, 4120, Nov. 2005, [Peer-reviewed]
  English, Scientific journal
• Modulation of the midlatitude ionospheric E region by atmospheric gravity waves through polarization electric field
  T Yokoyama; T Horinouchi; M Yamamoto; S Fukao
  JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 109, A12, Dec. 2004, [Peer-reviewed]
  English, Scientific journal
• The lateral transport of zonal momentum due to Kelvin waves in a meridional circulation
  T Imamura; T Horinouchi; TJ Dunkerton
  JOURNAL OF THE ATMOSPHERIC SCIENCES, 61, 15, 1966, 1975, Aug. 2004, [Peer-reviewed]
  English, Scientific journal
• Simulated breaking of convectively generated mesoscale gravity waves and airglow modulation
  T Horinouchi
  JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS, 66, 6-9, 755, 767, Apr. 2004, [Peer-reviewed]
  English, Scientific journal
• Modulation of the midlatitude ionospheric e region by atmospheric gravity waves through polarization electric field
  T. Yokoyama; T. Horinouchi; M. Yamamoto; S. Fukao
  Journal of Geophysical Research: Space Physics, 109, 12, Blackwell Publishing Ltd, 2004, [Peer-reviewed]
  English, Scientific journal
• Tropical cumulus convection and upward-propagating waves in middle-atmospheric GCMs
  T Horinouchi; S Pawson; K Shibata; U Langematz; E Manzini; MA Giorgetta; F Sassi; RJ Wilson; K Hamilton; J de Grandpre; AA Scaife
  JOURNAL OF THE ATMOSPHERIC SCIENCES, 60, 22, 2765, 2782, 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
• High time resolution determination of the tropical tropopause by the Equatorial Atmosphere Radar
  MK Yamamoto; M Oyamatsu; T Horinouchi; H Hashiguchi; S Fukao
  GEOPHYSICAL RESEARCH LETTERS, 30, 21, Nov. 2003, [Peer-reviewed]
  English, Scientific journal
• Convective impact on temperatures observed near the tropical tropopause
  SC Sherwood; T Horinouchi; HA Zeleznik
  JOURNAL OF THE ATMOSPHERIC SCIENCES, 60, 15, 1847, 1856, Aug. 2003, [Peer-reviewed]
  English, Scientific journal
• Kelvin-Helmholtz instability around the tropical tropopause observed with the Equatorial Atmosphere Radar (vol 30, pg art. no. 1476, 2003)
  MK Yamamoto; M Fujiwara; T Horinouchi; H Hashiguchi; S Fukao
  GEOPHYSICAL RESEARCH LETTERS, 30, 13, Jul. 2003, [Peer-reviewed]
  English
• 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]
  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
• Convectively generated mesoscale gravity waves simulated throughout the middle atmosphere
  T Horinouchi; T Nakamura; J Kosaka
  GEOPHYSICAL RESEARCH LETTERS, 29, 21, Nov. 2002, [Peer-reviewed]
  English, Scientific journal
• Sea-breeze circulation over Jakarta, Indonesia: A climatology based on boundary layer radar observations
  TW Hadi; T Horinouchi; T Tsuda; H Hashiguchi; S Fukao
  MONTHLY WEATHER REVIEW, 130, 9, 2153, 2166, Sep. 2002, [Peer-reviewed]
  English, Scientific journal
• Mesoscale variability of tropical precipitation: Validation of satellite estimates of wave forcing using TOGA COARE radar data
  T Horinouchi
  JOURNAL OF THE ATMOSPHERIC SCIENCES, 59, 16, 2428, 2437, Aug. 2002, [Peer-reviewed]
  English, Scientific journal
• The quasi-biennial oscillation
  MP Baldwin; LJ Gray; TJ Dunkerton; K Hamilton; PH Haynes; WJ Randel; Holton, JR; MJ Alexander; Hirota, I; T Horinouchi; DBA Jones; JS Kinnersley; C Marquardt; K Sato; M Takahashi
  REVIEWS OF GEOPHYSICS, 39, 2, 179, 229, May 2001, [Peer-reviewed]
  English
• Synoptic-scale Rossby waves and the geographic distribution of lateral transport routes between the tropics and the extratropics in the lower stratosphere
  T Horinouchi; F Sassi; BA Boville
  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 105, D21, 26579, 26592, Nov. 2000, [Peer-reviewed]
  English, Scientific journal
• On the dynamics of easterly waves, monsoon depressions, and tropical depression type disturbances
  AH Sobel; T Horinouchi
  JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN, 78, 2, 167, 173, Apr. 2000, [Peer-reviewed]
  English, Scientific journal
• Wave-mean flow interaction associated with a QBO-like oscillation simulated in a simplified GCM
  T Horinouchi; S Yoden
  JOURNAL OF THE ATMOSPHERIC SCIENCES, 55, 4, 502, 526, Feb. 1998, [Peer-reviewed]
  English, Scientific journal
• Propagation of waves exited by localized episodic heating in the tropics and their effect on the middle atmosphere: Comparison between two QBO phases
  T Horinouchi; S Yoden
  JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN, 75, 3, 641, 656, Jun. 1997, [Peer-reviewed]
  English, Scientific journal
• Excitation of transient waves by localized episodic heating in the tropics and their propagation into the middle atmosphere
  T Horinouchi; S Yoden
  JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN, 74, 2, 189, 210, Apr. 1996, [Peer-reviewed]
  English, Scientific journal
• Wave excitation by localized heating in the tropics and its propagation into the middle atmosphere
  T Horinouchi; S Yoden
  TENTH CONFERENCE ON ATMOSPHERIC AND OCEANIC WAVES AND STABILITY, 230, 231, 1995, [Peer-reviewed]
  English, International conference proceedings
• KELVIN WAVE ACTIVITY AND THE QUASI-BIENNIAL OSCILLATION IN THE EQUATORIAL LOWER STRATOSPHERE
  M SHIOTANI; T HORINOUCHI
  JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN, 71, 1, 175, 182, Feb. 1993, [Peer-reviewed]
  English

• Road to the first star: Venus orbiter from Japan (58) - Winds and waves at the cloud top -
  Horinouchi T., Planetary People - The Japanese Society for Planetary Sciences, 33, 2, 190, 192, 25 Jun. 2024
  The Japanese Society for Planetary Sciences, Japanese
• 熱帯太平洋温暖化による将来の北半球極渦の非対称化
  松村伸治; 山崎孝治; 堀之内武, 日本気象学会大会講演予稿集(CD-ROM), 120, 2021
• Road to the first star: Venus orbiter from Japan (42) ‒ Superrotation ‒
  Horinouchi T., Planetary People - The Japanese Society for Planetary Sciences, 29, 2, 75, 79, 25 Jun. 2020
  The Japanese Society for Planetary Sciences, Japanese
• 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, [Peer-reviewed]
  Japanese, Meeting report
• Overview of Akatsuki data products: definition of data levels, method and accuracy of geometric correction
  Kazunori Ogohara; Masahiro Takagi; Shin ya Murakami; Takeshi Horinouchi; Manabu Yamada; Toru Kouyama; George L. Hashimoto; Takeshi Imamura; Yukio Yamamoto; Hiroki Kashimura; Naru Hirata; Naoki Sato; Atsushi Yamazaki; Takehiko Satoh; Naomoto Iwagami; Makoto Taguchi; Shigeto Watanabe; Takao M. Sato; Shoko Ohtsuki; Tetsuya Fukuhara; Masahiko Futaguchi; Takeshi Sakanoi; Shingo Kameda; Ko ichiro Sugiyama; Hiroki Ando; Yeon Joo Lee; Masato Nakamura; Makoto Suzuki; Chikako Hirose; Nobuaki Ishii; Takumi Abe, Earth, Planets and Space, 69, 01 Dec. 2017
  English
• Performance of Akatsuki/IR2 in Venus orbit: The first year 7. Planetary science Akatsuki at Venus: The First Year of Scientific Operation Masato Nakamura, Dmitri Titov, Kevin McGouldrick, Pierre Drossart, Jean-Loup Bertaux and Huixin Liu
  Takehiko Satoh; Takehiko Satoh; Takao M. Sato; Masato Nakamura; Yasumasa Kasaba; Munetaka Ueno; Makoto Suzuki; George L. Hashimoto; Takeshi Horinouchi; Takeshi Imamura; Atsushi Yamazaki; Takayuki Enomoto; Yuri Sakurai; Kosuke Takami; Kenta Sawai; Takashi Nakakushi; Takumi Abe; Nobuaki Ishii; Chikako Hirose; Naru Hirata; Manabu Yamada; Shin Ya Murakami; Yukio Yamamoto; Tetsuya Fukuhara; Kazunori Ogohara; Hiroki Ando; Ko Ichiro Sugiyama; Hiroki Kashimura; Shoko Ohtsuki, Earth, Planets and Space, 69, 1, 01 Dec. 2017
  Springer Science and Business Media LLC
• あかつきIR2カメラが探る金星の中下層雲における多様性
  佐藤毅彦; 佐藤隆雄; 中村正人; 上野宗孝; 笠羽康正; はしもと じょーじ; 中串孝志; LIMAYE Sanjay; 堀之内武, 日本気象学会大会講演予稿集, 112, 2017
• 金星雲頂高度に発見された巨大重力波
  福原哲哉; はしもと じょーじ; 堀之内武; 今村剛; 岩上直幹; 神山徹; 村上真也; 中村正人; 小郷原一智; 佐藤光輝; 佐藤隆雄; 鈴木睦; 田口真; 高木聖子; 上野宗孝; 渡部重十; 山田学, 日本気象学会大会講演予稿集, 110, 2016
• 金星大気中に発見された巨大定在重力波
  田口真; 神山徹; 今村剛; 堀之内武; 福原哲哉; 二口将彦; はしもと じょーじ; 岩上直幹; 村上真也; 小郷原一智; 佐藤光輝; 佐藤隆雄; 鈴木睦; 高木聖子; 上野宗孝; 渡部重十; 山田学; 山崎敦; 中村正人, 地球電磁気・地球惑星圏学会総会及び講演会(Web), 140th, 2016
• 金星周回軌道における「あかつき」初期科学成果の概要
  佐藤毅彦; 中村正人; 今村剛; 山崎敦; 鈴木睦; 上野宗孝; 山田学; 福原哲哉; 小郷原一智; 大月祥子; 村上真也; 佐藤隆雄; 渡部重十; 岩上直幹; 田口真; 高橋幸弘; はしもと じょーじ; 堀之内武; 高木征弘; 神山徹, 地球電磁気・地球惑星圏学会総会及び講演会(Web), 140th, 2016
• 「あかつき」金星周回軌道における初期科学成果の概要
  佐藤毅彦; 中村正人; 今村剛; 山崎敦; 鈴木睦; 上野宗孝; 山田学; 福原哲哉; 小郷原一智; 大月祥子; 村上真也; 佐藤隆雄; 渡部重十; 岩上直幹; 田口真; 高橋幸弘; はしもと じょーじ; 山本幸生; 堀之内武; 高木征弘; 神山徹, 日本惑星科学会秋季講演会予稿集(Web), 2016, 2016
• B304 北西太平洋SST変動に対する梅雨降水帯の応答(熱帯・中高緯度,成層圏・対流圏結合変動過程と異常気象の予測可能性,スペシャル・セッション)
  松村 伸治; 堀之内 武; 杉本 志織; 佐藤 友徳, 大会講演予講集, 108, 347, 347, 2015
  日本気象学会, Japanese
• C313 雲追跡技法の利用と金星雲頂高度での風速構造(「あかつき」金星大気探査カウントダウン,スペシャル・セッション)
  神山 徹; 今村 剛; 佐藤 毅彦; 中村 正人; 高木 征弘; 小郷原 一智; 樫村 博基; 佐藤 尚毅; 堀之内 武, 大会講演予講集, 108, 366, 366, 2015
  日本気象学会, Japanese
• C407 夏季の東アジア・北西太平洋域の総観規模変動,水蒸気輸送,降水への上部対流圏の渦位擾乱の影響(降水システムII,一般口頭発表)
  堀之内 武, 大会講演予講集, 105, 348, 348, 2014
  日本気象学会, Japanese
• A412 秋雨期の降水と水輸送に対する台風の影響(気象システムII,口頭発表)
  谷澤 隼人; 堀之内 武, 大会講演予講集, 103, 340, 340, 2013
  日本気象学会, Japanese
• B202 赤道付近の季節平均降水量への混合Rossby重力波の影響(熱帯大気,口頭発表)
  堀之内 武, 大会講演予講集, 103, 188, 188, 2013
  日本気象学会, Japanese
• C162 成層圏突然昇温時の大規模前線構造(続報)(中層大気研究の新展開,専門分科会)
  堀之内 武, 大会講演予講集, 101, 92, 92, 2012
  日本気象学会, Japanese
• A417 地球流体データサーバ構築ツールGfdnavi : 新しい解析・可視化UI(気候システムIII,一般口頭発表)
  大塚 成徳; 西澤 誠也; 堀之内 武; 電脳davisプロジェクト, 大会講演予講集, 101, 409, 409, 2012
  日本気象学会, Japanese
• D112 水惑星実験によるハドレー循環における対流と結合した波動の役割(大気力学,一般口頭発表)
  堀之内 武, 大会講演予講集, 100, 291, 291, 2011
  日本気象学会, Japanese
• 310 地球流体データのデータベース・解析・可視化のためのデスクトップツール兼サーバー「Gfdnavi」の開発(オーラルセッション10 惑星気象・惑星大気)
  西澤 誠也; 堀之内 武; 渡辺 知恵美; 伴林 晃紀; 諫本 有加; 大塚 成徳, 日本惑星科学会秋期講演会予稿集, 2009, 61, 61, 28 Sep. 2009
  日本惑星科学会, Japanese
• A cross-search mechanism using Faceted Navigation for Gfdnavi
  ISAMOTO Yuka; WATANABE Chiemi; HORINOUCHI Takeshi; NISHIZAWA Seiya, IEICE technical report, 109, 186, 21, 26, 31 Aug. 2009
  We are developing Gfdnavi, which is a integrated desktop tool and it can search, analyze and visualize geophysical fluid data. Though we can search only the data of accessed server, the number of servers for Gfdnavi will increase. Then we develop a cross-search mechanism among public Gfdnavi servers so that scientists can share scientific datasets. To achieve this, we apply Gfdnavi query interface to Faceted Navigation mechanism for querying data. Therefore, users can easily search data of public Gfdnavi servers. And we use existing web service of Gfdnavi to develop a cross-search., The Institute of Electronics, Information and Communication Engineers, Japanese
• 教育研究プログラム「Elucidation of ground-based atmosphere observetion network in equatorial Asia」の初年度活動報告
  津田敏隆; 藤吉康志; 山本真之; 古本淳一; 中村卓司; 堀之内武; 岩崎杉紀, 第2回赤道大気レーダーシンポジウム 第105回生存圏シンポジウム, 25 Sep. 2008
  Japanese
• Practical Data Analysis Using Open Source Software : 5. Ruby for Geophysical Fluid Sciences
  HORINOUCHI Takeshi, Journal of plasma and fusion research, 84, 4, 217, 227, 25 Apr. 2008
  プラズマ・核融合学会, Japanese
• C163 COSMIC GPS掩蔽データからのSwathデータの作成と初期結果(大気リモートセンシングデータ解析技術における工夫,専門分科会)
  堀之内 武; 東 洋佑; 津田 敏隆, 大会講演予講集, 93, 207, 207, 2008
  日本気象学会, Japanese
• D212 COSMIC GPS掩蔽データによる大気重力波の鉛直断面の解析(大気力学II)
  堀之内 武, 大会講演予講集, 93, 281, 281, 2008
  日本気象学会, Japanese
• Metadata schema design and query interface for Gfdnavi: a data archiving server construction support tool for geophysical fluid database
  柳平 有美; 渡辺 知恵美; 堀之内 武, DBSJ letters, 6, 1, 153, 156, Jun. 2007
  日本データベース学会, Japanese
• P224 地球流体データの公開・共有・解析・可視化のためのツールGfdnaviの開発
  堀之内 武; 西澤 誠也; 渡辺 知恵美; 神代 剛; 塩谷 雅人; 森川 靖大; 林 祥介; 石渡 正樹; 電脳davisプロジェクト, 大会講演予講集, 91, 306, 306, 30 Apr. 2007
  社団法人日本気象学会, Japanese
• 惑星宇宙望遠鏡TOPS:計画の概要ならびにサイエンス検討の現状
  高橋幸弘; 坂野井健; 上野宗孝; 笠羽康正; 吉田和哉; 田口真; 山崎敦; 岩上直幹; 今村剛; 鈴木睦; 阿部琢美; 寺田直樹; 寺田直樹; 土屋史紀; 堀之内武; 中島健介; 高橋幸弘; 高橋幸弘, 地球電磁気・地球惑星圏学会総会及び講演会予稿集(CD-ROM), 122nd, 2007
• 惑星宇宙望遠鏡TOPSによる中性大気観測の検討
  堀之内武; 中島健介; 中串孝志; 小高正嗣; 杉山耕一朗; 竹内覚; 佐藤毅彦; 今村剛; 坂野井健; 高橋幸弘; 岩上直幹; 高橋幸弘, 地球電磁気・地球惑星圏学会総会及び講演会予稿集(CD-ROM), 122nd, 2007
• Information technology and meteorology
  HORINOUCHI Takeshi, 天気, 54, 11, 941, 944, 2007
  日本気象学会, Japanese
• An intense gravity wave near the mesopause region observed by a Fabry-Perot interferometer and an airglow imager
  Shiokawa K; S. Suzuki; Y. Otsuka; T. Ogawa; T. Nakamura; T. Horinouchi, J. Geophys. Res, 112, D7, D07106, 2007
• Temperature and Humidity Monitoring with GPS Occultation and the Contribution to the Global Earth Observation System of Systems (GEOSS)(RECENT RESEARCH ACTIVITIES)
  Tsuda Toshitaka; Nakamura Takuji; Horinouchi Takeshi, Sustainable humanosphere : bulletin of Research Institute for Sustainable Humanosphere Kyoto University, 2, 5, 5, 31 Aug. 2006
  Kyoto University, English
• Report on the International Workshop on Regional Models for the Prediction of Tropical Weather and Climate
  YODEN Shigeo; SAITO Kazuo; SATOMURA Takehiko; SEKO Hiromu; TSUBOKI Kazuhisa; HORINOUCHI Takeshi, 天気, 53, 8, 629, 633, 2006
  日本気象学会, Japanese
• B160 大気重力波と熱帯中層大気の高解像度モデリング(スペシャルセッション「高解像度気候モデルによる中層大気研究の可能性」)
  堀之内 武, 大会講演予講集, 90, 107, 107, 2006
  日本気象学会, Japanese
• C103 赤道大気レーダー(EAR)による熱帯上部対流圏の鉛直流観測(熱帯大気)
  山本 真之; 堀之内 武; 山本 衛; 橋口 浩之; 深尾 昌一郎; 庭野 将徳; 西 憲敬, 大会講演予講集, 90, 149, 149, 2006
  日本気象学会, Japanese
• 赤道大気レーダーによる対流圏内の鉛直流観測－EAR/雲レーダーの同時観測結果について－
  山本真之; 庭野将徳; 西憲敬; 阿保真; 熊谷博; 大野裕一; 堀江宏昭; 岡本創; 永田肇; 堀之内武; 山本衛; 橋口浩之; 深尾昌一郎, 「赤道大気上下結合」平成18年度公開ワークショップ集録, 2006/9/14-15, 京都市, 19-25, 2006,, 2006, [Peer-reviewed]
  Japanese
• A209 スマトラおよびその近海における積雲対流と重力波の数値実験 : 対流の日変化(熱帯大気I)
  堀之内 武, 大会講演予講集, 88, 66, 66, 2005
  日本気象学会, Japanese
• MC11:Climate Model Evaluation : How Well Do Models Represent Observations(Report on the XXIII General Assembly of the International Union of Geodesy and Geophysics(IUGG2003)(3))
  HORINOUCHI Takeshi, 天気, 51, 5, 385, 385, 2004
  Japanese
• 大気重力波による中緯度電離圏E領域の変動に関する数値シミュレーション
  横山竜宏; 堀之内武; 山本衛; 深尾昌一郎, 大気圏シンポジウム, 18th, 89, 92, 2004
  Japanese
• Morphology of Venusian clouds
  IMAMURA Takeshi; SHIMOYAMA Manabu; HORINOUCHI Takeshi, Planetary people, 12, 4, 254, 260, 25 Dec. 2003
  The Japanese Society for Planetary Sciences, Japanese
• P354 子午面流中の赤道波による運動量輸送の一般論
  堀之内 武; 今村 剛, 大会講演予講集, 83, 425, 425, 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
• B303 熱帯対流圏界面の短周期変動(熱帯大気)
  山本 真之; 堀之内 武; 橋口 浩之; 山本 衛; 深尾 昌一郎; 森 修一; 山中 大学, 大会講演予講集, 84, 136, 136, 2003
  日本気象学会, Japanese
• D308 積雲対流による重力波の励起と中間圏界面付近における砕波の数値実験(大気力学・中層大気)
  堀之内 武, 大会講演予講集, 83, 218, 218, 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
• Development of a Programming Basis for Earth and Planetary Fluid Sciences with Ruby
  HORINOUCHI TAKESHI; KAWANABE NAOKI, 情報処理学会論文誌プログラミング（PRO）, 43, 8, 113, 113, 15 Sep. 2002
  Data used in earth and planetary fluid sciences are in many cases physical quantities that are discretely sampled or discretized on a grid. Since there are more than a few data formats even if we limit our scope to widely used ones, it is useful to take object-oriented approaches to handle them. Meanwhile, to analyze data it is needed for a researcher to do programming rather than to use GUI in order to flexibly develop and apply new techniques and to accumulate them. Therefore, since the end users (researchers) program daily, it would be needed a language that is suitable for rapid development as well as being object-oriented. However, such a language is rarely used in the present research activities. In order to make Ruby, an object-oriented scripting language, suitable for such activities we have ported basic libraries such as mathematical and graphic ones and are developing a library based on a class of "discretized physical quantities". The class hides realization of data on computers and is devised to cover a wide variety of physical quantity data in the field. It is shown with examples that research program development becomes efficient by using the class even when using only one data formats and that to adopt a program to different data formats becomes easy. A future development will be directed to build a basis for rapid programming of distributed huge datasets., Information Processing Society of Japan (IPSJ), Japanese
• 熱帯の降雨の変動成分 : 赤外画像からの波動励起推定法の検討
  堀之内 武, 大会講演予講集, 80, 74, 74, 10 Oct. 2001
  Japanese
• ラジオゾンデ観測データに基づく赤道域インドネシアにおける大気重力波の研究
  岩間 陽介; 堀之内 武; 津田 敏隆; SARASPRIYA Slamet; MANIK Timbul, 大会講演予講集, 80, 230, 230, 10 Oct. 2001
  Japanese
• 始動した赤道大気レーダー : Equatorial Atmosphere Radar ; EAR
  深尾 昌一郎; 津田 敏隆; 山本 衛; 中村 卓司; 橋口 浩之; 堀之内 武; 佐藤 亨; SADEWO A.; NURYANTO A.; MUZIRWAN M.; KARTASASMITA M., 大会講演予講集, 80, 81, 81, 10 Oct. 2001
  Japanese
• 多次元配列 NumArray および Ruby/DCL を用いた描画ライブラリの開発
  川那辺 直樹; 堀之内 武; 塩谷 雅人; 後藤 謙太郎; 黒井 啓子, 大会講演予講集, 79, 423, 423, 08 May 2001
  Japanese
• 赤道域積雲対流起源大気重力波の中層大気への伝播(3次元数値実験から)
  小坂 純一; 堀之内 武, 大会講演予講集, 79, 396, 396, 08 May 2001
  Japanese
• 赤道域積雲対流によって励起される大気重力波の数値実験
  小坂 純一; 堀之内 武, 大会講演予講集, 78, 257, 257, 18 Oct. 2000
  Japanese
• 様々な中層大気GCM中の低緯度の波動の解析
  堀之内 武, 大会講演予講集, 78, 36, 36, 18 Oct. 2000
  Japanese
• 多次元数値データの自己記述的入出力ライブラリ gtool4/Fortran90 の開発 : Fortran 90 モジュール構成と移植性
  豊田 英司; 石渡 正樹; 林 祥介; 竹広 真一; 堀之内 武; 地球流体電脳倶楽部; davis プロジェクト, 大会講演予講集, 78, 429, 429, 18 Oct. 2000
  Japanese
• Development of gtool4 : a self-descriptive storage format for multi-dimensional numerical data
  TOYODA Eizi; ISHIWATARI Masaki; HAYASHI YoshiYuki; AKAHORI Koji; NUMAGUTI Atusi; GFD-Dennou Club; Davis Project, Proceedings, ... meeting of Japan Society of Fluid Mechanics, 2000, 361, 362, 25 Jul. 2000
  Storage format for multi-dimensional numerical data is developed for the purpose of researches mainly on geophysical fluid phenomena. In order to achieve platform-independency, netCDF is used for low-level file format. NetCDF conventions for variables and attributes are presented to realize self-descriptiveness, which flexibly support visualization information and various kind of grid-structure. A visualization and analysis software written in Fortran 90 is now under development in order to demonstrate self-descriptiveness of the data format, Japan Society of Fluid Mechanics, Japanese
• 大規模大気波動に伴う物質輸送とその季節変動・年々変動
  余田 成男; 石岡 圭一; 牛丸 真司; 佐藤 薫; 堀之内 武; 向川 均, 大会講演予講集, 77, 78, 78, 24 May 2000
  Japanese
• 多次元数値データの自己記述的格納形式 gtool4 の開発
  豊田 英司; 石渡 正樹; 林 祥介; 赤堀 浩司; 堀之内 武; 沼口 敦, 大会講演予講集, 77, 395, 395, 24 May 2000
  Japanese
• 7.MW01:対流圏-成層圏のGCM相互比較(第22回国際測地学地球物理学連合総会(IUGG99)報告(1))
  堀之内 武, 天気, 47, 1, 20, 20, 2000
  Japanese
• 簡単化したGCM中のQBO的振動の力学
  堀之内 武; 余田 成男, 大会講演予講集, 71, 88, 88, May 1997
  Japanese
• 第１回ＳＰＡＲＣ国際研究集会の報告
  廣田勇; 高橋正明; 塩谷雅人; 佐藤薫; 秋吉英治; 堀之内武; 内藤陽子; 荻野慎也; 清水厚; 山之内淳史, 天気, 44, 7, 467, 473, 1997
• 簡単なGCMによる波と帯状流に関する数値実験
  堀之内 武; 余田 成男, 大会講演予講集, 69, 240, 240, 21 May 1996
  Japanese
• 10th Conference on Atmospheric and Oceanic Waves and Stability
  Ishioka Keiichi; Sato Kaoru; Satoh Masaki; Takahashi Masaaki; Nozawa Toru; Horinouchi Takeshi; Yamane Shozo; Yoden Shigeo, 天気, 43, 2, 113, 118, 1996
  日本気象学会, Japanese
• 熱帯での加熱により励起された波動の中層大気への伝播
  堀之内 武; 余田 成男, 大会講演予講集, 67, 45, 45, 15 May 1995
  Japanese
• Long-term variations of Kelvin wave activity in the equatorial lowe rstratosphere
  Shiotani, M; T. Horinouchi, International Symposium on Middle Atmosphere Science, Kyoto, Japan, Mar. 1992
  English

• 図説台風の事典
  筆保, 弘徳; おくむら, 政佳; 横浜国立大学台風科学技術研究センター
  朝倉書店, Jun. 2025, 9784254161403, x, 193p, Japanese, [Joint work]

• 大気力学特論, 2024年, 修士課程, 環境科学院

• American Geophysical Union
• 地球電磁気・地球惑星圏学会
• 日本気象学会

• 波と対流が形作る金星大気大循環：地表から超高層大気まで
  科学研究費助成事業
  Apr. 2024 - Mar. 2029
  今村 剛; 三好 建正; 高木 征弘; 杉本 憲彦; 榎本 剛; 堀之内 武; はしもと じょーじ; 佐川 英夫; 樫村 博基
  日本学術振興会, 基盤研究(S), 東京大学, Competitive research funding, 24H00021
• Study of dynamic-thermodynamic structure and intensification process of super-typhoon by aircraft observation
  Grants-in-Aid for Scientific Research
  05 Jul. 2021 - 31 Mar. 2026
  坪木 和久; 伊藤 耕介; 山田 広幸; 堀之内 武; 篠田 太郎; 高橋 暢宏; 清水 慎吾; 大東 忠保; 南出 将志; 辻野 智紀; 山口 宗彦
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (S), Nagoya University, 21H04992
• Comprehensive picture of atmospheric circulation of Venus revealed by AKATSUKI data assimilation
  Grants-in-Aid for Scientific Research
  26 Jun. 2019 - 31 Mar. 2024
  林 祥介; 高木 征弘; 榎本 剛; はしもと じょーじ; 杉本 憲彦; 今村 剛; 堀之内 武; 石渡 正樹; 三好 建正
  データ同化に向けて「あかつき」観測データを精錬、雲追跡風ベクトル場を生成し、そこから大気諸相の特徴を抽出すること、および、データ同化試行実験を開始するとともに、データ同化の有効性を検証することに注力して研究を進めた。
  大気諸相の特徴を抽出する研究で得られた成果の１つは雲層低緯度でのスーパーローテーションの維持機構を史上初めて観測から定量的に明らかにしたことである。「あかつき」撮像データからの雲追跡風ベクトル場と雲頂温度場、さらに、過去の探査機データをも活用し、各種大気波動による角運動量輸送量を求めることに成功した。低緯度の角運動量分布極大の維持には大気熱潮汐波による角運動量輸送が支配的であり、過去の研究で示唆されてきた大規模な乱流や熱潮汐波以外の波動による輸送は弱くむしろ逆に働いていた。この結果は今後のデータ同化実験に供され、得られた同化データの解析によってこれをもたらす循環構造が解明されていくことが期待される。
  データ同化の有効性を検証する研究の成果の１つは、同化実験における雲層上端の惑星規模ケルビン波の再現可能性を示したことである。金星大気の紫外線画像には顕著なY字模様が見えるが、これを維持する構造として雲層上端に惑星規模赤道ケルビン波が想像されてきた。しかし、金星大気モデルで雲層上端にケルビン波を再現した例はこれまで報告されていなかった。この問題に対して、雲追跡風ベクトルを模した疑似観測データを与え、データ同化による観測システムシミュレーション実験を行い、雲層上端の赤道域南北15度の範囲で6時間ごとの風速データがあれば、ケルビン波がデータ同化により表現できることがわかった。「あかつき」観測の中に雲層上端のケルビン波をとらえているデータが存在すれば、モデルの不完全性を観測が補完し、あるいは、不完全性の原因を追求できる可能性があることを示した。
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (S), Kobe University, 19H05605
• 新世代気象衛星の台風高頻度観測による高精度風プロダクト開発と台風の変動過程の解明
  科学研究費助成事業
  01 Apr. 2019 - 31 Mar. 2023
  堀之内 武; 筆保 弘徳; 林 昌宏; 嶋田 宇大; 柳瀬 亘
  2019年台風15号の発生環境場の特徴的な点を統計的に検出した。また，室内実験を用いて，台風内部構造で発生する非軸対象構造の再現を行った。2012年8月に高い緯度で非対称構造を伴って発生した台風Kirogiについて，大気追跡風と数値シミュレーションを利用して解析を行い， Kirogiの発生には，中緯度起源の上層トラフの接近，および，この年に強かった亜熱帯の傾圧性が影響していることを明らかにした。ひまわり8号等の新世代気象衛星の赤外放射観測を用いた台風周辺の気温・水蒸気量鉛直プロファイル推定手法の開発を行った。合成開口レーダー（SAR）観測の風プロダクトと台風ベストトラックを比較した結果，眼形成前の小型サイズの発達台風はSAR風がベストトラックの風より大きい傾向がわかった。米国の静止気象衛星で観測された雷データより，発達ハリケーンでは定常ハリケーンに比べて内部コアで雷の発生数が多いことを明らかにした。2020年の台風10号(Haishen)に対しひまわり８号を用いて実施した30秒間隔での特別観測結果より，高密度・高時間分解能な風速推定に成功した。その結果，目の中に局在しエネルギーが線形に成長する特殊な順圧不安定が，目の中の回転の加速をもたらしたことが明らかになった。SARにより求まる最大風速半径が，静止衛星画像から良い精度で推定できることを明らかにした。単一の気象ドップラーレーダーから水平風速場を推定する新しい手法を開発し，これまでの手法に対する優位性を確認し，Haishenに適用した。
  日本学術振興会, 基盤研究(A), 北海道大学, 19H00705
• A study on the atmospheric circulation of Venus by the use of AKATSUKI data assimilation
  Grants-in-Aid for Scientific Research
  01 Apr. 2019 - 31 Mar. 2020
  林 祥介; はしもと じょーじ; 杉本 憲彦; 今村 剛; 堀之内 武; 三好 建正; 石渡 正樹
  本研究のコアである、地球シミュレータ上で最適化された大気大循環モデルAFESを核とした金星大気大循環モデルAFES-Venusの開発と数値実験ならびにそれを用いたデータ同化試行を進めた。特に、金星大気データ同化システム（ALEDAS-V）の実装検証としては、欧州の探査機 Venus Express から得られていた風速データを同化し金星大気熱潮汐波の位相修正への効果を吟味し、大気大循環に大きな影響を与えることを最終的に確認、これを発表した。一方、データ同化を活用した観測計画実証として、複数の小型衛星による電波掩蔽観測を想定した擬似観測データをデータ同化することにより金星大気高緯度の特徴的構造であるコールドカラーの観測可能性を検討、２－３機の小型衛星による多点観測により意義のある観測が実現できることが検証され、データ同化による金星大気観測設計の可能性が示された。
  また、「あかつき」観測からの知見の集積に関しては、「あかつき」冬季集中観測の結果の集計に着手し、画像データから雲風ベクトル解析を進めるとともに、これまで得られてきた雲追跡風ベクトルの統計こよって得られた知見をもとに、金星大気の子午面循環とスーパーローテーションに関する理論的・数値的研究を進め、特に、TEM数値モデル（変換オイラー平均子午面循環=擾乱による統計的な輸送を考慮した比較的単純な理論的循環モデル）の上にこれらをまとめて解釈することを試み、これを発表するとともに、今後の研究の理論考察の対象、すなわち、子午面循環構造に対する仮説の一つとしてこれを位置づけた。
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Kobe University, 19H00720
• Unveiling the material circulation in the Venusian atmosphere with coordinated spacecraft and ground-based observations
  Grants-in-Aid for Scientific Research
  01 Apr. 2016 - 31 Mar. 2020
  NAKAMURA MASATO
  The atmospheric material circulation on Venus related to cloud formation has been studied by cooperative observations by Akatsuki spacecraft and ground-based telescopes and numerical modeling. We have clarified the structure of the mean meridional circulation and the characteristics of various planetary-scale waves, which may be related to the maintenance of the high-speed zonal flow, by cloud tracking using infrared images covering the whole local time as well as ultraviolet images. We obtained observational clues that angular momentum transport caused by thermal tides contributes to the maintenance of high-speed zonal winds. For integrating observational data with numerical modeling, data assimilation was successfully conducted. The global temperature structure was observed by radio occultation. The cloud physics was introduced into the atmospheric general circulation model, and the distribution of sulfuric acid clouds consistent with the observations was reproduced.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Japan Aerospace EXploration Agency, 16H02231
• Atmospheric dynamics with new potential-vorticity analysis
  Grants-in-Aid for Scientific Research
  01 Apr. 2016 - 31 Mar. 2019
  Horinouchi Takeshi; Matsumura Shinji
  This study was conducted to advance the methodology to analyze meteorological data such as satellite data, objective analysis data and numerical simulation data and further to advance our understanding of weather systems by advancing potential vorticity-based analysis that we had developed. We elucidated the mechanism of upper-tropospheric driving of summertime synoptic precipitation over East Asia and the Northwestern Pacific. It was also revealed that such meteorological knowledge and methodology help explain climate projection by climate models.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 16K05550
• Study of the role of transient atmospheric disturbances in the climate system over the tropics
  Grants-in-Aid for Scientific Research
  01 Apr. 2013 - 31 Mar. 2016
  Horinouchi Takeshi
  This study was conducted to elucidate the roles of transient atmospheric disturbances in the climate system over the tropics to subtropics. Relationship among convectively coupled mixed Rossby-gravity waves, seasonal precipitation and sea surface temperature was elucidated. It was shown that summertime synoptic-scale Rossby waves that propagate along subtropical jet modulate water-vapor transport and induce vertical motion to form precipitation belts that co-vary with the jet. The findings will be useful to evaluate climate prediction.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 25400460
• Spatiotemporal variability, multi-level structures, and water transport in the tropical climate system
  Grants-in-Aid for Scientific Research
  2010 - 2012
  HORINOUCHI Takeshi
  The theory of the Hadley circulation was revisited by using aqua-planet numerical modeling and theoretical examination. It was revealed that a degree of freedom, which is overlooked by the conventional theory, exists in its strength, and that equatorial wave disturbances can act to constrain it. It is shown that fluctuation on synoptic time scales induced by waves including the mixed Rossby-gravity waves exists in the low cloud amount over the equatorial south eastern Pacific. It is also shown that the waves have a relationship with mean precipitation.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 22540444
• Elucidation of atmospheric structure and disturbance phenomenon by GPS radio occultations
  Grants-in-Aid for Scientific Research
  2009 - 2011
  TSUDA Toshitaka; HORINOUCHI Takeshi; SHOJI Yoshinori; SEKO Hiromu; KAWATANI Yoshio; YABUKI Masanori; SATO Kazutoshi; KAWABATA Takuya; KUNII Masaru
  This research project is concerned with GPS meteorology, which utilizes satellite positioning data, represented by GPS and QZSS (Quasi Zenith Satellite System), to the studies of the atmosphere. We carried out research in the following three themes:1) retrieval of high-resolution temperature and water vapor profiles obtained by the GPS radio occultation (RO) mission with small LEO (low Earth orbit) satellites, 2) evaluation of the forecast improvement by assimilation of both GPS-RO and ground-based GPS-PWV (precipitable water vapor) data into a numerical weather prediction model, and 3) analysis of time and space variations of atmospheric structure and disturbance
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Kyoto University, 21340138
• Studies on the Effects of the Stratosphere on Climate Change and its Dynamical Role
  Grants-in-Aid for Scientific Research
  2008 - 2011
  YODEN Shigeo; ISHIOKA Keiichi; NAITO Yoko; MUKOUGAWA Hitoshi; HORINOUCHI Takeshi; KODERA Kunihiko; HIROOKA Toshihiko; TAGUCHI Masakazu; SHIBATA Kiyotaka
  Effects of the stratospheric change on the main dynamical processes of the general circulation of the atmosphere and their dynamical role were clarified with data analyses of global observations and numerical studies with a hierarchy of numerical models from a dynamical core to the JMA operational model of one-month ensemble numerical weather prediction. Some specific findings associated with a stratospheric sudden warming event are large-scale frontal structure at the edge of circumpolar vortex and systematic predictability variation of the annular mode before and after the event. A chemistry-climate model was also used in addition to the above data and models, and the dynamical influences of external forcings, such as the stratospheric cooling and variations of the solar activity, on the intra-seasonal and inter-annual variations of the atmosphere were elucidated.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Kyoto University, 20244076
• 地球科学データの高度利用と流通のための基盤開発
  科学研究費助成事業
  2009 - 2010
  堀之内 武; 渡辺 知恵美; 西澤 誠也; 林 祥介; 石渡 正樹; 小高 正嗣
  近年の地球観測と計算機の進展により,大気や水,環境汚染物質などの数値データは爆発的に増加しており,対応が急務である.我々は18年度より,検索,解析,可視化機能に富み,個人や小グループによるデータ整理や研究遂行からWebでの多機能なデータ公開サイト構築までをシームレスに支える,新しいタイプのソフトウェアGfdnaviを開発してきた.本研究課題は,これをさらに発展させ,次を実現することを目的として実施した.(1)データから得られた知見を文書化する機能を発展させ,科学データ,データ解析プロセスと有機的に結びついた形での知識の集積を可能とする.(2)Gfdnaviサーバ間のオーバレイネットワークを実用化する.(3)実用性をさらに向上させる.本年度は以下の成果を得た.
  昨年度に提案及び基本実装を行った「スクリプティングによる逐次アクセスと親和的なRESTful webサービス」を強化した.これにより,オブジェクト指向スクリプト言語Rubyにおいて地球流体の研究者がローカルデータの解析に用いるライブラリとWebサービスのクライアントライブラリの統合が進んだ.さらにデータから得られる知見を文書化する機能のAPIを完成し,大量のデータ処理から文書を自動生成できるようにした.(目的(1),(3))
  Gfdnaviサーバ間のネットワークのハブとなるサーバを開発し,運用を開始した.その過程でピアツーピア環境におけるファセット検索実現に掛かる新手法を提案した.(目的(2))
  データ解析可視化基礎ライブラリの強化:Gfdnavi等で用いられている,地球流体データ解析・可視化のための基礎ライブラリGPhysを強化し,適用範囲を広げた.(目的(3))
  日本学術振興会, 特定領域研究, 北海道大学, 21013002
• 地球科学データの高度利用と流通のための基盤開発
  科学研究費助成事業
  2007 - 2008
  堀之内 武; 渡辺 知恵美; 塩谷 雅人; 石渡 正樹; 小高 正嗣; 西澤 誠也
  本研究では, 地球流体科学における数値データのネットワーク利用を促進し, 同分野での情報爆発問題の解決に資するための共通基盤ソフトウェアGfdnaviを開発している. 平成20年度は以下を実施した.
  数値データと知見情報の融合的なデータベース化 : 昨年度開発した, データ解析で得られた可視化結果等をもとに科学的な知見を文書化しアーカイブし研究や情報公開に役立てる機能を, 強化した. 数値データおよび解析履歴と密接に結びついたブログ/Wikiによる共同研究という, 新しいスタイルでの共同研究をサポートするための提案と基礎開発を行った.
  Gfdnaviの相互検索・横断利用 : 昨年度より, Gfdnaviのオーバレイネットワークを構築し, 横断的にデータや知見を検索・利用するための手法を研究している. 本年度は, プロトタイプ実装を行った.
  次年度実装に向けた基礎研究 : 筑波大で開発された, httpベースのファイルアクセスライブラリにおいて地球流体データを扱う際のボトルネックを検討した. その結果今後の改良により, 特別なサーバソフトなしに, Web上に置かれただけの地球流体データをGfdnaviで扱えるようにできる見通しを得た. また, これまで用いていたSOAPによるWebサービスから, リソース志向のRESTfulなWebサービスに切り替えるための検討を行い開発に着手した(今後に継続).
  実利用の拡充と応用開発 : 2009年に打ち上げが予定されている環境観測衛星SMILESのデータ公開および科学チーム検証サーバにGfdnaviが採用されることになり, 人工衛星データむけの対応を行った(継続).
  日本学術振興会, 特定領域研究, 19024039
• 多次元・多重な地球環境データの管理と高度利用
  科学研究費助成事業
  2006 - 2006
  堀之内 武; 林 祥介; 城 和貴; 芦野 俊宏; 塩谷 雅人; 竹広 真一
  近年の地球観測と計算機の進展により、大気や水、環境汚染物質などのデータは爆発的に増加している。本課題は、これら「地球流体」データの情報爆発問題に対処し、専門研究者や環境対策・防災等のための利用者にむけて使いやすい形でデータを提供し、さらに手持ちデータも含めて解析可視化できるような仕組みとシステムを開発することを目的として遂行した。その結果、研究者各人や小グループのデータアーカイブ、解析、可視化から、一般向けの(解析可視化可能な形での)データ公開までをシームレスにサポートする、これまでにない新しいツールGfdnaviを成功裏に開発した。
  Gfdnaviは、これまでに我々が開発してきた、オブジェクト指向言語Rubyによる地球科学データ解析可視化ライブラリ群と、包括的なWebアプリケーション開発フレームワークRuby on Railsを組み合わせて実現した。本課題では、以下の研究・開発を行い、いずれもGfdnaviに取り込む形で実用化した。
  ●地球科学データのメタデータの自動抽出と階層的な関係データベース化
  ●キーワード及び時空間情報による検索、地図を用いた検索
  ●数値データの解析可視化ユーザインタフェース
  ●解析可視化基盤ライブラリの強化
  さらに、今後の展望を踏まえて、次の研究を行った。
  ●P2Pによるオーバレイネットワークの構築と分散ハッシュを用いた横断検索
  ●データから得られる知見情報をもとデータと有機的に関連づけて保存することによる知識ベース化の基礎検討
  なお、Gfdnaviはhttp://www.gfd-dennou.org/arch/davis/gfdnaviにて公開している。
  日本学術振興会, 特定領域研究, 京都大学, 18049043
• 大規模数値実験による積雲対流起源の重力波の励起と作用の研究
  科学研究費助成事業
  2005 - 2006
  堀之内 武
  地表面から100km以上に至る広い高度領域の気候システムにおける、積雲対流起源の大気重力波の役割を調べるため、雲を陽に分解する領域気象モデルを用いた数値実験と理論的研究を行った。本年度は、熱帯対流圏の季節内振動に応じて上方へ伝播する波動がどのように変調されるかを調べた。2004年4-5月にインドネシアのスマトラ島で行われた集中観測を対象に、雲分解モデルによるシミュレーションを行った。その結果、季節内振動の活発期(降雨の多い時期)には、対流圏の擾乱の振幅は大きいものの、成層圏に伝播する重力波はかえって、(運動量の絶対ベースでみて)非活発期よりも小さくなるという結果が得られた。これは、季節内振動の位相進行に応じて、運動量やエネルギーが上方に抜ける効率が変化することを示唆する。その原因は、近年観測的に指摘されている、位相進行に伴う対流の鉛直構造の変化に起因すると考えられる。さらに、詳細なメカニズム解明に向けて研究を行っている。
  季節内振動不活発期における対流の日変化の研究を行った。スマトラ島西岸など、熱帯の多くの沿岸域で見られる、夜間に対流域が沖合に伝播する現象を再現した。解析の結果、大気下層を水平に伝播する重力波によりプレコンディショニングが行われ、さらにコールドプール移流により対流域が移動することが示された。
  一方、観測的研究においては、中間圏の大気光画像に見られる、対流起源と思われる事例の波動パラメタを特定した。また、流星レーダーに見られる約7日周期の波動の特性を明らかにした。
  日本学術振興会, 若手研究(B), 京都大学, 17740309
• Space-time variations of equatorial Kelvin wave activity around the tropical tropopause region
  Grants-in-Aid for Scientific Research
  2004 - 2005
  SHIOTANI Masato; NISHI Noriyuki; HORINOUCHI Takeshi; EGUCHI Nawo
  Space-time variations of the temperature and the zonal wind around the tropical tropopause region are examined using the European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis data set (ERA-40). The spectral analysis is performed to calculate power spectra in the zonal wavenumber and frequency domain for the zonal wind data. Two spectral peaks are found : one is in a region with frequency 0.035-0.25[1/day] and zonal wavenumber 1-10 for the Kelvin wave, and the other in a region with frequency 0.011-0.035[1/day] and zonal wavenumber 1-10 for the Intraseasonal Oscillation (ISO). On the basis of these frequency-wavenumber domains the grid data are reconstructed to represent Kelvin wave and the ISO activities, and the variances are calculated from the gridded data to see space-time variations of the Kelvin wave and the ISO. The ISO activity is clearly related to the eastward propagating convections, though the Kelvin wave activity is organized around 60゜E (the western Indian Ocean) throughout the year. We selected Kelvin wave events from the reconstructed zonal wind data with a threshold of -2.938 [m/s] to see the life cycle of the Kelvin waves. Kelvin waves with high activity around 60゜E begin mostly around 30゜W to 60゜E and disappear around 60゜E to 150゜E. By performing the composite analysis for the Kelvin wave events we found that the Kelvin wave generation is closely coupled with the convective event, though the area of the Kelvin wave generation does not correspond to the active convective area such as in the western Pacific.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Kyoto University, 16540398
• Development of a portable water vapor profiler in the lower troposphere using a small Raman lidar
  Grants-in-Aid for Scientific Research
  2003 - 2005
  NAKAMURA Takuji; ABO Makoto; TSUDA Toshitaka; FURUMOTO Junichi; HASHIGUCHI Hiroyuki; HORINOUCHI Takeshi
  We have developed a transportable Raman lidar for water vapor profiling at around 200 m altitude, which is the lower boundary of a L-band wind profiler radar. A small Nd:YAG laser with a SHG of 532 nm is used for transmission and the same wavelength (532 nm), N2 Raman (607 nm) and H20 Raman (660 nm) scatters are received with a photon counting system, by means of a 35.5 cm telescope. The water vapor mixing ratio around 200 m could be observed both day and night, and the system was equipped at the Shigaraki MU observatory, Shiga, Japan for a long time. The system calibration factor did not change for more than 6 months within a deviation of 4 - 5 %. Water vapor could be profiled well for most of the times except for a rare case of the low altitude clouds or fogs. When we adjust the system to use a larger iris, water vapor mixing ratio profiles could be observed up to 3 - 4 km altitude. This lidar has been improved to be controlled remotely through a network. On the other hand, observations in a horizontal direction as well as a field observation on board a vehicle have been carried out. We found that fluctuations of waver vapor as large as 10 % over the national forest around Shigaraki observatory, as well as correlation with aerosol intensity. The measurement of water vapor content in the volcanic gas emitted from Nakadake, Mt. Aso has been successfully carried out, which is the first time of the remote-sensing measurement of H20 in the volcanic gas. As mentioned above, this study has achieved much more than we had expected at the beginning, as an application of a small Raman lidar.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), KYOTO UNIVERSITY, 15340156
• 積雲対流起源の大気重力波の大規模モデリングによる研究
  科学研究費助成事業
  2003 - 2004
  堀之内 武
  近年、積雲対流により励起され鉛直伝播する小規模重力波が、成層圏・中間圏において果たす役割の認識が高まっている。研究代表者はこれまでに、世界に先駆けて、積雲対流を陽に再現する領域気象モデルを用いて地表から高度100kmまでの大気重力波をシミュレートすることに成功した。本年度は、中間圏界面付近での重力波の砕波に伴う大気光擾乱の発生過程ならびに電離層プラズマ擾乱への影響過程を調べる一方で、対流圏における大気重力波励起の理論的検討ならびにスマトラ島での事例への適用を行った。
  積雲対流による重力波励起の高分解能(水平0.5km,鉛直0.3km)計算を行い、大気光の一つである酸素原子の557.7nmの発光強度を見積った。これにより、大気光の地上観測にしばしば見られる縞構造がモデルで再現された。結果の詳細な解析を通じ、モデル中の砕波においては、幅10km程度の縞模様を産み出す秩序構造と、より小規模な乱流が共存していることが明らかになった(Horinouchi, 2004)。また、Yokoyamaによる電離層プラズマモデルの計算の入力データとして用い、スポラディックE層におけるプラズマ擾乱生成の新しいメカニズムを発見した(Yokoyama et al., 2004)。
  一方で、積雲対流による大気重力波励起に関する理論的研究を行った。励起の「パラメタリゼーション」という形での従来理論と、数値実験結果の比較により、従来の理論の問題と、その解決のための提案を行った(Chun, Song, and Horinouchi, J.Atmos.Sci.,投稿中)。また、山岳を含む場での現実的な重力波励起を調べるべく、スマトラ島でのキャンペーン観測にあわせた雲分解数値実験を行った(投稿準備中)。
  日本学術振興会, 若手研究(B), 京都大学, 15740292
• Collaborative observations of atmospheric waves and constituent variations in the MLT region using ground-based observation network in Japan and America with satellite observations.
  Grants-in-Aid for Scientific Research
  2002 - 2004
  NAKAMURA Takuji; TSUDA Toshitaka; HORIUCHI Takeshi; NOMURA Akio; SHIOKAWA Kazuo; ABO Makoto
  The goal of this project is to clarify various spatial and temporal scales of variations, especially variations of atmospheric waves and associated constituent variations, in the mesosphere lower thermosphere (MLT) region by ground-based using radio and optical observation in the Japan, USA and Brazil as well as satellite observations.
  From coordinated observations at Shigaraki MU radar site, relations between atmospheric gravity waves and variations of airglow emission profiles have been revealed. A new OH all-sky imager has been developed and coordinated observations with a sodium lidar and two imagers have been carried out (CO2 imager campaign) in Colorado, USA. Relations between ripple structures in the airglow image and atmospheric stability have been clarified.
  Associations between troposheric disturbance and gravity waves in the MLT region have been found by observations and ray-tracing using airglow imaging observations in Japan, USA and Brazil. Effect of atmospheric tides are also discussed.
  Non-migrating tides has been studied using radar, satellite observations and a GCM model, and zonal variability of airglow image characteristics has been suggested. Three-dimensional simulation has clarified breaking gravity waves and ripple structures in the airglow.
  As mentioned above, the results of this project is not limited to the simple output of coordinated observations and spread over a wider research region, which would further stimulate future collaboration between Japan, USA and Brazil in the upper atmosphere region.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Kyoto University, 14403008
• Development of Combined Remote-sensing Technique of Humidity Profiles
  Grants-in-Aid for Scientific Research
  2002 - 2003
  TSUDA Toshitaka; AOAYAMA Yuichi; HORINOUCHI Takeshi; NAKAMURA Takuji; FURUMOTO Junichi
  Humidity is the most important parameters to elucidate the detailed behavior of meteorological phenomena. However, a remote-sensing sensing technique to continuously monitor humidity profiles has not been fully available for practical use. In this study a new remote-sensing technique for water vapor profiling has been developed based on the humidity estimation technique with an atmosphere radar. The other remote sensing method, i.e. Raman lidar and GPS have been developed aimed at more precise estimation combining these data accordingly. The detail of the study is summarized as follows.
  1. Radar remote-sensing technique to estimate humidity profiles was developed using a correlation between the turbulent echo intensity with an atmosphere radar and vertical humidity gradient. In the method we also incorporated GPS precipitable water vapor data into the retrieval algorithm for a stable estimation. The humidity profiles with the MU radar-RASS successfully elucidated the detailed humidity structure in rain-clouds which had not been observed by other conventional techniques.
  2. A lidar system at the Shiraraki observatory was improved to detect rotation Raman signal to enable to monitor temperature and humidity profiles. The new system also inserted a narrow-band optical filter which allows us a daytime observation.
  3. The humidity estimation method developed with the MU radar was applied to a wind profiler radar, operated on L-band to monitor detailed humidity profiles in an atmospheric boundary layer. By combining that with the MU radar-RASS measurement, we successfully estimated humidity profiles at a wide height range between 0.2-7.5 km.
  4. Downward-looking (DL) GPS radio occultation technique is known to provide the atmospheric temperature and humidity profiles with high vertical resolution. With the objective of making this DL technique practicable, we performed the measurement experiment on the top of Mt.Fuji. We succeeded in retrieving the temperature and humidity profiles, which agree with the radiosonde observations near Mt.Fuji, from the DL measurement data.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Kyoto University, 14340140
• 大気大循環モデルによる下層・中層大気の波動と積雲対流の比較研究
  科学研究費助成事業
  2001 - 2002
  堀之内 武
  各国の代表的な中層大気大循環モデルにおける赤道域の大気波動を、比較研究した。前年度に行った下部成層圏の波動の解析にひき続き、今年度は上部成層圏、中間圏の波動を解析した.その結果、中間圏における高速ケルビン波が中間圏の運動量且収支に果たす寄与はどのモデルでも小さく、また、多くのモデルで無視可能に近いことがわかった.中間圏におけるケルビン波の重要性については諸説あるが、今回は下層大気における積雲対流も含めて多くのモデルについて解析しており、現実大気においても同様であることがほぼ確実となった.一方、これまで中間圏下部では、その重要性についてほとんど議論すらされたことのない、太陽非同期潮汐が、幾つかのモデルでは一定の役割を果たしていることが示された。さらに、積雲パラメタリゼーションのクロージャーの仮定に応じて、波動励起特性がどのように変わるかを示した。(以上、Horinouchi et al.,2003)
  熱帯での積雲対流により励起される波動をさらに調べるため、気象メソスケールモデルの鉛直高度範囲を100kmまで拡大した初めての数値実験を行ない、中間圏界面における波動砕波の過程を明らかにした(Horinouchi et al.,2002).モデルの設定を様々に変えてさらに調べ、大気光イメージング観測に見られる砕波との対応関係を示した(Horinouhi,2003,J.Atmos.Solar Terr.Phys.,投稿中)。
  日本学術振興会, 若手研究(B), 京都大学, 13740278
• International coordinated observation of hectors at the tropical region in the northern Australia
  Grants-in-Aid for Scientific Research
  2001 - 2002
  TSUDA Toshitaka; HORINOUCHI Takeshi; NAKAMURA Takuji
  About 50-100 km offshore from Darwin, which is the central city on the Northern Territory, Australia, the two islands (Buthurst, Melville), called Tiwi Islands, are facing across a narrow strait. The very characteristic isolated type huge cumulonimbus cloud called Hector appears over these islands. We carried out the international common observation campaign (DAWEX: Darwin Area Wave Experiment) around Darwin in October to December, 2001, in order to study the generation of atmospheric waves by cumulonimbus clouds (Hector). In collaboration with the Australian Bureau of Meteorology (BOM), Monash university, and the university of Adelaide, we conducted radiosonde observation campaigns. In order to investigate the horizontal propagation characteristic of the atmospheric waves from the Hector, we selected 3 balloon launch sites; Garden Point on the Tiwi Islands, Darwin and Katherine, which are aligned on a nearly straight line with maximum distance of about 400km. We launches a total of 40 radiosondes every 3 hours from the 3 places for over 5 days in 3 periods; the comparatively calm dry season in the middle of October (10/13-18), and the active Hector periods in the second half of November (11/15-20) and mid-December (12/11-16). According to statistics of the balloon burst height, more than 3/4 reached the 25km, about 2/3 exceeded 30km.
  From a preliminary analysis of the observed profiles, we detected near the tropopause a persistent wave phenomenon with an oscillation period of about 84 hours. Since there is almost no phase difference among three observation points, this wave seems to have a large horizontal scale. Similar wave activities were also seen in November and December. We extracted the atmospheric gravity waves with a vertical scale smaller than about 3km, and estimated the wave energy from wind velocity and temperature fluctuations. The wave energy was enhanced at 15-20 km and 25-30 km, but, the gravity waves were considerably depressed at 20-25 km. The overall structure of the wave energy seems to correlate with the background zonal winds, though the underlying physical mechanism has not been clarified yet.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), KYOTO UNIVERSITY, 13573005
• 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
• Material transports associated with large-scale waves and their seasonal and interannual variations
  Grants-in-Aid for Scientific Research
  1999 - 2002
  YODEN Shigeo; MUKOUGAWA Hitoshi; HORINOUCHI Takeshi; NAITO Yoko; USHIMARU Shinji; ISHIOKA Keiichi; SATO Kaoru
  Nonlinear behaviors of large-scale atmospheric waves in the troposphere and the stratosphere were investigated with a hierarchy of numerical models, which we have been developed and used. Material transport processes associated with these waves were also studied with some tracer models. Seasonal dependence, interannual variations, and trends of the wave behaviors were also clarified by analyzing long records of numerical time-integrations and global observation data.
  1. Model development : A numerical library to solve geophysical fluid motions in some typical geometries efficiently in supercomputers has been developed. As application tests of the models, 2-D decaying turbulence on a rotating sphere and gravity wave radiation in a rotating shallow water system are investigated.
  2. Planetary waves : A global circulation model with simplified physical processes was used to investigate the effects of the equatorial QBO winds on planetary waves and mean meridional circulation in the winter hemisphere. It was demonstrated that large sample method based on long enough data is a powerful tool to show the statistical significance of the QBO effects. In order to study horizontal mixing and transport barrier in winter stratosphere, assimilated data for 9 years from 1990 were used to do local Lyapunov stability analysis and compute Lagrange trajectories of many particles. Interannual variations of the mixing were quantified with these analyzes.
  3. Baroclinic waves : Long time integrations of an atmospheric GCM were done with an idealized SST to investigate the dynamics of localized storm tracks. It was found that the most important factor to determine the localization is nonzonal (west-east) component of the meridional gradient of SST in mid-latitudes.
  4. Equatorial gravity waves : Generation, propagation and breaking processes of convectively generated gravity waves were firstly simulated with a meso-scale non-hydrostatic numerical model from the surface to the lower thermosphere (about 100 km height). An estimation method of convectively generated waves in the equatorial region based on satellite observations of IR radiation was developed and tested.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research on Priority Areas, Kyoto University, 11219203
• Climatological study of the latitudinal, longitudinal, and height distribution of atmospheric gravit wave energy
  Grants-in-Aid for Scientific Research
  1999 - 2001
  TSUDA Toshitaka; SHIMIZU Atsushi; HORINOUCHI Takeshi; NAKAMURA Takuji; YOSHIHARA Takayuki
  1. Analyses of the gravity waves with the GPS occultation technique
  The global distribution of the atmospheric gravity waves was investigated with temperature data obtained by using the occultation technique for the GPS (Global Positioning System)signals. This study revealed the global distribution of the amplitude of gravity waves for the first time [Tsuda et al., 2000a]. We could also observe gravity waves from mountain ranges [Hocke et al., 2002]. Also revealed is the global morphology of the tropopause [Nishida et al., 2000]. We could further show that the occurrence of the ionospheric sporadic E layer is correlated with the activity of gravity waves in the stratosphere [Hocke et al., 2002].
  2. Radar observations
  The results with the GPS observations mentioned above was confirmed with the MU radar at Shigaraki and the White Sands radar in the United States [Nastrom, 2000]. We further showed that the breaking of gravity waves sometimes cause a large spatial variation of wind speed in a short distance [Nakamura et al., 2002]. Gravity waves in low latitudes were investigated with the MF radar in Indonesia to show their inter-annual and ultra-seasonal variability [Isoda, et al., 2002; Tsuda et al.,2002]. Methods to infer gravity wave excitation using meteorological radars were investigated as well [Horinouchi, 2002].
  3. Radio sonde observations
  Long-term observational data in Indonesia was analyzed to show seasonal variability of the gravity waves in the upper troposphere [Shimizu et al.,2001]. Latitudinal variation of the gravity wave amplitude was also investigated [Alexander et al., 2002].
  4. Optical observation
  Gravity waves in the mesopause-lower thermosphere region were investigated with CCD imagers,and the seasonal variation of their dominant propagation direction was revealed [Tsuda et al., 2000b, Nakamura, 200l].
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), KYOTO UNIVERSITY, 11440142
• Collaborative Experiments of Convection and Gravity Waves
  Grants-in-Aid for Scientific Research
  1999 - 2000
  TSUDA Toshitaka; HORINOUCHI Takeshi; NAKAMURA Takuji; HASEBE Fumio; SHIMIZU Atsushi; NISHI Noriyuki
  1. Balloon Observation of the troposphere and the stratosphere
  By using daily radiosonde soundings from 1993 to 1996 in the equatorial Kalimantan, we have investigated long-term variability of atmospheric gravity waves and found their seasonal variation in the troposphere and a modulation by the Quasi-Biennial Oscillation in the stratosphere.
  We have conducted an observational campaign to launch radiosondes 4 times daily at three sites in each of Java, Sumatra, and Kalimantan Islands from November to December, 2000. Gravity waves were identified in the stratosphere, and their latitudinal dependence was revealed. Vertical wavenumber spectra showed tails with a -3 exponent down to the vertical wave length of 200m. Conventional theories have explained this feature in terms of saturation of gravity waves. Interestingly, however, it was shown that no saturation was seen in the observed lower stratosphere.
  2. Observation of gravity waves with all-sky imagers
  An all-sky imager was installed in the suburb of Bandung, Indonesia to observe gravity waves projected onto OH airglow. We have successfully observed gravity waves at altitudes around 90km and studied horizontal structure and propagation. It was found that their propagation was mostly southward. The observation will be continued and is expected to provide data to reveal seasonal and year-to-year variability of the gravity waves.
  3. Observation of the mesosphere and lower thermosphere (MLT) by MF and meteor radars
  A new antenna was added to the MF radar in Kalimantan in order to make it capable of measuring the momentum flux associated with waves in the MLT region. With the MF radar and a meteor radar in Java, long-term variation of gravity waves and long-period planetary-scale waves were investigated. Activities of gravity and Kelvin waves were found to be weak throughout two years from 1996. It was also found that waves with 30- to 60-day periods correlate well with tropospheric intra-seasonal oscillation.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A)., KYOTO UNIVERSITY, 11694075
• Development of RASS system for atmospheric temperature sounding
  Grants-in-Aid for Scientific Research
  1997 - 1999
  NAKAMURA Takuji; MASUDA Yoshihisa; YAMAMOTO Mamoru; TSUDA Toshitaka; FURUMOTO Jun-ichi; HORINOUCHI Takeshi
  The goal of this project is to develop a RASS sounding system for atmospheric temperature measurement for the troposphere and the lower stratosphere to be attached to the MU radar using high power acoustic wave source, which can be operated continuously, routinely with a good precision.
  A system with a RASS control PC for ray tracing and control of acoustic wave sources, which is directly connected to the radar data processing system has been developed. Sophisticared ray tracing and observation control softwares have been developed.
  Using radio wave transmission of acoustic wave source from the observation room, a very stable system for acoustic wave source with a control of various wave sources has been realized. Through such system, acoustic array with full synchronization controlled from the radar observation room has been completed. This system enabled to observed up to tropopause in summer and mid-troposphere in winter.
  From the RASS observation with the developed system and radiosondes, atmospheric stability, radar echo intensity any energy dissipation rate have been closely studied and the correlations and interrelationship have been studied.
  Profiling technique of atmospheric humidity has also been developed by analyzing radar echo intensity and atmospheric stability from RASS measurement.
  Thus, the achivements of this project are more than the initial expectation, which have been published in domestic and international conferences and in journals.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), KYOTO UNIVERSITY, 09554022