博士（理学）, 東北大学

大気海洋相互作用

気候変動

海面水温

Natural Science, Atmospheric and hydrospheric sciences

Master's degree program, Graduate School of Environmental Science

Doctoral (PhD) degree program, Graduate School of Environmental Science

May 2011, Meteorological Society of Japan, JMSJ award
Youichi Tanimoto

Oct. 2002, Meteorological Society of Japan, Shono-Yamamoto Medal
Youichi Tanimoto

Linkage Between Late‐Summer Heat Waves Over Northeastern Siberia and Subsequent SST Cooling in the Western North Pacific
Xiling Zhou; Tomonori Sato; Shixue Li; Youichi Tanimoto
Atmospheric Science Letters, 27, 5, Wiley, 28 Apr. 2026, [Peer-reviewed]
Scientific journal, ABSTRACT

Sea surface temperature (SST) in the western North Pacific (WNP) strongly affects the regional marine ecosystem and modulates East Asian weather. Although the mechanisms of SST variability in the WNP have been extensively examined, it remains unclear how it is influenced by remote forcing from high‐latitude regions. Using reanalysis datasets spanning 1979–2024, this study examined the linkage between the summer atmospheric circulation over northeastern Siberia (NES) and autumn SST variability in the WNP and elucidated the underlying influencing processes. Results revealed that anomalous high pressure over NES in August, concurrent with frequent heat waves, is typically followed by colder autumn SST in the WNP. The ocean cooling is modulated by a low‐pressure system over the WNP, which reduces insolation through increased cloud cover and enhances evaporation via dry air advection. Together, these processes result in net surface heat loss, thereby contributing to subsequent SST cooling. This cooling, plausibly sustained by ocean thermal inertia, persists until November. This linkage, observed only following August heat waves over NES, is facilitated by the oceanic thermal structure characterized by a shallow mixed layer, which enhances the sensitivity of SST to surface heat loss. These findings suggest that the late‐summer atmospheric circulation over NES might be helpful in predicting autumn SST variability in the WNP and provide new insights into the connection between high‐latitude heat extremes and midlatitude SST variability.

Prolonged Extreme Heatwave Over Japan in 2025 Summer with July Dry Condition and Early-August Heavy Rainfall
Kazuto Takemura; Fumi Sezaki; Norihisa Fujikawa; Masahiro Watanabe; Yukiko Imada; Hiroaki Ueda; Ryuichi Kawamura; Tetsuya Takemi; Youichi Tanimoto; Masami Nonaka; Yayoi Harada; Takeshi Horinouchi; Hitoshi Mukougawa; Hiroaki Kawase; Shion Sekizawa; Hisashi Nakamura
SOLA, 22, 1, Springer Science and Business Media LLC, 10 Apr. 2026, [Peer-reviewed]
Scientific journal, Abstract

In 2025 Japan underwent record-high summer-mean temperature exceeding the preceding records set in 2023 and 2024. The prolonged heat in 2025 was attributable to a markedly persistent poleward shift of the subtropical jet (STJ) over the Asian continent and around Japan, associated with the early onset and persistent enhancement of Asian monsoonal convection. The early termination of the Baiu period caused extremely dry conditions nationwide in July. The remarkably-enhanced convection around the Philippines, where several typhoons sequentially formed, contributed to the marked northwestward extension of the North Pacific Subtropical High (NPSH) toward Japan through the Pacific-Japan (PJ) teleconnection in July. Sub-monthly events of Rossby-wave propagation along the STJ occasionally enhanced the extension of the upper-level Tibetan High toward Japan, causing the accentuated extreme heat. Persistent anomalous descent and increased insolation under the NPSH contributed to the record-high surface air temperatures. Global warming as well as above-normal sea-surface temperatures around Japan and over the midlatitude North Pacific may also have contributed to the record heatwave.In early August, intra-seasonally suppressed convection around the Philippines and Rossby-wave propagation over the Asian continent caused the southward-meandered STJ, with ascent along enhanced low-level moist airflow to cause locally heavy rainfall over Japan.

Subtropical Atmospheric Response to Extratropical SST Warming in the Western North Pacific Under Atmospheric Internal Variability
Itsuki Miura; Youichi Tanimoto
Geophysical Research Letters, 53, 4, American Geophysical Union (AGU), 12 Feb. 2026, [Peer-reviewed]
Scientific journal, Abstract

Sea surface temperature (SST) anomalies in the Kuroshio Extension (KE) region have been increasingly recognized as playing a key role in shaping the extratropical air–sea interactions. However, the extent to which such extratropical SST forcing can influence large‐scale atmospheric circulation and surrounding SST remains uncertain, particularly given strong atmospheric internal variability. Here, we investigate the atmospheric response to idealized positive SST anomalies in the KE region using large‐ensemble atmospheric general circulation model experiments. The imposed forcing generates a robust sea‐level pressure anomaly over and downstream of the KE, leading to surface westerly wind anomalies extending into the subtropical North Pacific. Despite substantial atmospheric internal variability over the Aleutian Low region, these subtropical wind anomalies consistently emerge across the ensemble. Our results suggest that SST forcing in the KE region can modulate air–sea interactions not only locally but also across a broader region extending equatorward.

Increasing Annual Subduction and Obduction Rates in the North Pacific Revealed by an Eddy-Resolving Ocean Reanalysis
Yoshimi Kawai; Shoichiro Kido; Yuma Miyaji; Youichi Tanimoto
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 130, 12, 18 Dec. 2025, [Peer-reviewed]
English, Scientific journal

Mesoscale eddy influence on North Pacific air–sea heat exchange in a high-resolution ocean reanalysis
Yuma Miyaji; Shoichiro Kido; Hiroyuki Tomita; Youichi Tanimoto
Journal of Oceanography, Springer Science and Business Media LLC, 08 Jul. 2025, [Peer-reviewed]
Scientific journal, Abstract

Thanks to advances in satellite observations and high-resolution ocean/climate modeling, the importance of ocean mesoscale eddies has been increasingly recognized in recent decades. However, more comprehensive and quantitative assessment of the role played by ocean mesoscale eddies in modulating the air–sea heat exchange is warranted to establish a complete picture of extratropical air–sea interaction. We extracted O (10⁵) areas of ocean mesoscale eddies in the North Pacific during 1993–2021 from an eddy-resolving ocean reanalysis dataset (JCOPE-FGO) using a non-tracking eddy detection method based on curvature vorticity at each grid point, instead of the conventional Lagrangian methods. The extracted grid points below (above) a threshold of negative (positive) curvature vorticity represent physical properties of the anti-cyclonic (cyclonic) eddies, including positive (negative) sea surface temperature (SST) anomalies. These positive (negative) SST anomalies on the warm (cold) eddies act to enhance (reduce) upward heat releases from the sea surface. The extracted warm and cold eddies exhibit asymmetries in number, spatial scale, and amplitude of associated surface heat flux anomalies, leading to a greater contribution of warm eddies to oceanic heat release. Owing to a slight latitudinal difference of the highest frequency between warm and cold eddies in the western North Pacific, the enhancement of the heat release overwhelms its reduction north of the Kuroshio Extension (KE), and vice versa south of the KE. We further discuss how such latitudinally asymmetric air–sea heat exchange anomalies influence the meridional ocean heat transport by mesoscale eddies and the mid-latitude atmospheric baroclinicity.

Large-Scale Factors for the Persistent Extreme Heatwave over Japan in 2024 Summer and Late-July Heavy Rainfall in Northern Japan
Kazuto Takemura; Hirotaka Sato; Hiroshi Nakamigawa; Shotaro Tanaka; Shuhei Maeda; Yukari N. Takayabu; Hiroaki Ueda; Ryuichi Kawamura; Masahide Kimoto; Youichi Tanimoto; Hiroaki Naoe; Masami Nonaka; Toshihiko Hirooka; Hitoshi Mukougawa; Masahiro Watanabe; Yukiko Imada; Hiroaki Kawase; Hisashi Nakamura
SOLA, 21, 329, 339, Meteorological Society of Japan, Jul. 2025, [Peer-reviewed]
Scientific journal

Impact of an unprecedented marine heatwave on extremely hot summer over Northern Japan in 2023
Hirotaka Sato; Kazuto Takemura; Akira Ito; Takafumi Umeda; Shuhei Maeda; Youichi Tanimoto; Masami Nonaka; Hisashi Nakamura
Scientific Reports, 14, 1, Dec. 2024, [Peer-reviewed]
Scientific journal

Preliminary Diagnosis of Primary Factors for an Unprecedented Heatwave over Japan in 2023 Summer
Kazuto Takemura; Hirotaka Sato; Akira Ito; Takafumi Umeda; Shuhei Maeda; Masayuki Hirai; Yuko Tamaki; Hirokazu Murai; Hiroshi Nakamigawa; Yukari N. Takayabu; Hiroaki Ueda; Ryuichi Kawamura; Youichi Tanimoto; Hiroaki Naoe; Masami Nonaka; Toshihiko Hirooka; Hitoshi Mukougawa; Masahiro Watanabe; Hisashi Nakamura
SOLA, 20, 69, 78, Meteorological Society of Japan, 2024, [Peer-reviewed]
Scientific journal

Mechanism and impact of zonally contrasting seasonal variations in sea-surface salinity in the North Pacific and North Atlantic Oceans
Shoichiro Kido; Shota Katsura; Masami Nonaka; Youichi Tanimoto
Progress in Oceanography, 103124, 103124, Elsevier BV, Sep. 2023, [Peer-reviewed]
Scientific journal

Classification of Interannual Surface Layer Salinity Variability
S. Katsura; J. Sprintall; S. Kido; Y. Tanimoto; M. Nonaka
Geophysical Research Letters, 50, 8, American Geophysical Union (AGU), 23 Apr. 2023, [Peer-reviewed]
Scientific journal, Abstract

Since surface layer salinity (SLS) mainly reflects sea surface freshwater flux and affects ocean circulation and upper ocean stratification by modifying seawater density, knowledge of SLS variability is important to better understand the global hydrological cycle and ocean and climate variability. The global pattern of SLS interannual variability has not received as much attention compared to the seasonal variability. The SLS interannual variability in the global ocean based on Argo profiling float data over 2003–2020 was classified into seven individual clusters. SLS interannual variability was found to be regionally different even within each ocean basin and primarily corresponded to large‐scale climate mode variability. The spatial distribution of the classified SLS clusters provides the first map of SLS interannual variability in the global ocean that largely reflects the variability of the global hydrological cycle.

Intercomparisons of methods for extracting the internal climate variability from the observed records over the Indo-Pacific sector
Yuma Miyaji; Takuya Hasegawa; Youichi Tanimoto
INTERNATIONAL JOURNAL OF CLIMATOLOGY, 43, 1, 57, 75, Jan. 2023, [Peer-reviewed]
English, Scientific journal

Projected future changes in the contribution of Indo-Pacific sea surface height variability to the Indonesian throughflow
Vivek Shilimkar; Hiroto Abe; Mathew Koll Roxy; Youichi Tanimoto
Journal of Oceanography, Springer Science and Business Media LLC, 14 May 2022, [Peer-reviewed]
Scientific journal, Abstract

The Indonesian throughflow (ITF) transports a significant amount of warm freshwater from the Pacific to the Indian Ocean, making it critical to the global climate system. This study examines decadal ITF variations using ocean reanalysis data as well as climate model simulations from the Coupled Model Inter-comparison Project Phase 5 (CMIP5). While the observed annual cycle of ITF transport is known to be correlated with the annual cycle of sea surface height (SSH) difference between the Pacific and Indian Oceans, ocean reanalysis data (1959–2015) show that the Pacific Ocean SSH variability controls more than 85% of ITF variation on decadal timescales. In contrast, the Indian Ocean SSH variability contributes less than 15%. While those observed contributions are mostly reproduced in the CMIP5 historical simulations, an analysis of future climate projections shows a 25–30% increase in the Indian Ocean SSH variability to decadal ITF variations and a corresponding decrease in the Pacific contribution. These projected changes in the Indian Ocean SSH variability are associated with a 23% increase in the amplitudes of negative zonal wind stress anomalies over the equatorial Indian Ocean, along with a 12º eastward shift in the center of action in these anomalies. This combined effect of the increased amplitude and eastward shift in the zonal wind stress increases the SSHA variance over the Indian Ocean, increasing its contribution to the ITF variation. The decadal ITF changes discussed in this study will be crucial in understanding the future global climate variability, strongly coupled to Indo-Pacific interactions.

Sea Surface Temperature–Salinity Covariability and its Scale‐dependent Characteristics
Shoichiro Kido; Masami Nonaka; Youichi Tanimoto
Geophysical Research Letters, 48, 24, 09 Dec. 2021, [Peer-reviewed]
English, Scientific journal

Impacts of Salinity Variation on the Mixed‐Layer Processes and Sea Surface Temperature in the Kuroshio‐Oyashio Confluence Region
Shoichiro Kido; Masami Nonaka; Youichi Tanimoto
Journal of Geophysical Research: Oceans, 126, 8, Aug. 2021, [Peer-reviewed]
English, Scientific journal

Primary Factors behind the Heavy Rain Event of July 2018 and the Subsequent Heat Wave in Japan
Shimpo Akihiko; Takemura Kazuto; Wakamatsu Shunya; Togawa Hiroki; Mochizuki Yasushi; Takekawa Motoaki; Tanaka Shotaro; Yamashita Kazuya; Maeda Shuhei; Kurora Ryuta; Murai Hirokazu; Kitabatake Naoko; Tsuguti Hiroshige; Mukougawa Hitoshi; Iwasaki Toshiki; Kawamura Ryuichi; Kimoto Masahide; Takayabu Izuru; Takayabu Yukari N; Tanimoto Youichi; Hirooka Toshihiko; Masiunoto Yukio; Watanabe Masahiro; Tsuboki Kazuhisa; Nakamura Hisashi
SOLA, 15A, A, 13, 18, 15 Jun. 2019, [Peer-reviewed]
Scientific journal

Simultaneous formation of the oceanic Rossby waves in the eastern North and South Pacific during the ENSO events.
Abe, H; Y. Tanimoto; T. Hasegawa; N. Ebuchi
Journal of Physical Oceanography, 46, 11, 3397, 3414, Nov. 2016, [Peer-reviewed]
English, Scientific journal

Oceanic Rossby Waves over Eastern Tropical Pacific of Both Hemispheres Forced by Anomalous Surface Winds after Mature Phase of ENSO
Hiroto Abe; Youichi Tanimoto; Takuya Hasegawa; Naoto Ebuchi
JOURNAL OF PHYSICAL OCEANOGRAPHY, 46, 11, 3397, 3414, Nov. 2016, [Peer-reviewed]
English, Scientific journal

Contribution of sea-surface wind curl to the maintenance of the SST gradient along the upstream Kuroshio Extension in early summer
Naoki Sato; Masami Nonaka; Yoshikazu Sasai; Hideharu Sasaki; Youichi Tanimoto; Ryuichi Shirooka
JOURNAL OF OCEANOGRAPHY, 72, 5, 697, 705, Oct. 2016, [Peer-reviewed]
English, Scientific journal

Significant Atmospheric Circulation Anomalies over the North Pacific Associated with the Enhanced Pacific ITCZ during the Summer-Fall of 2014
Shuhei Maeda; Yusuke Urabe; Kazuto Takemura; Tamaki Yasuda; Youichi Tanimoto
SOLA, 12, 282, 286, 2016, [Peer-reviewed]
English, Scientific journal

Active Role of the ITCZ and WES Feedback in Hampering the Growth of the Expected Full-Fledged El Nino in 2014
Shuhei Maeda; Yusuke Urabe; Kazuto Takemura; Tamaki Yasuda; Youichi Tanimoto
SOLA, 12, 17, 21, 2016, [Peer-reviewed]
English, Scientific journal

Separation of Climatological Imprints of the Kuroshio Extension and Oyashio Fronts on the Wintertime Atmospheric Boundary Layer: Their Sensitivity to SST Resolution Prescribed for Atmospheric Reanalysis
Ryusuke Masunaga; Hisashi Nakamura; Takafumi Miyasaka; Kazuaki Nishii; Youichi Tanimoto
JOURNAL OF CLIMATE, 28, 5, 1764, 1787, Mar. 2015, [Peer-reviewed]
English, Scientific journal

Continuous Daily Observation of the Marine Atmospheric Boundary Layer over the Kuroshio by a Helicopter Shuttle Service
Youichi Tanimoto; Kou Shimoyama; Shoichi Mori
JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY, 32, 1, 3, 21, Jan. 2015, [Peer-reviewed]
English, Scientific journal

Oceanic Rossby waves induced by the meridional shift of the ITCZ in association with ENSO events
Hiroto Abe; Youichi Tanimoto; Takuya Hasegawa; Naoto Ebuchi; Kimio Hanawa
JOURNAL OF OCEANOGRAPHY, 70, 2, 165, 174, Apr. 2014, [Peer-reviewed]
English, Scientific journal

Southward Eddy Heat Transport Occurring along Southern Flanks of the Kuroshio Extension and the Gulf Stream in a 1/10 degrees Global Ocean General Circulation Model
Kunihiro Aoki; Shoshiro Minobe; Youichi Tanimoto; Yoshikazu Sasai
JOURNAL OF PHYSICAL OCEANOGRAPHY, 43, 9, 1899, 1910, Sep. 2013, [Peer-reviewed]
English, Scientific journal

Intraseasonal SST-precipitation relationship and its spatial variability over the tropical summer monsoon region
Mathew Roxy; Youichi Tanimoto; B. Preethi; Pascal Terray; R. Krishnan
CLIMATE DYNAMICS, 41, 1, 45, 61, Jul. 2013, [Peer-reviewed]
English, Scientific journal

Influence of sea surface temperature on the intraseasonal variability of the South China Sea summer monsoon
Mathew Roxy; Youichi Tanimoto
CLIMATE DYNAMICS, 39, 5, 1209, 1218, Sep. 2012, [Peer-reviewed]
English, Scientific journal

Regional Patterns of Wintertime SLP Change over the North Pacific and Their Uncertainty in CMIP3 Multi-Model Projections
Kazuhiro Oshima; Youichi Tanimoto; Shang-Ping Xie
JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN, 90A, 385, 396, Feb. 2012, [Peer-reviewed]
English, Scientific journal

Sea Level Pressure Minimum along the Kuroshio and Its Extension
Youichi Tanimoto; Tomohisa Kanenari; Hiroki Tokinaga; Shang-Ping Xie
JOURNAL OF CLIMATE, 24, 16, 4419, 4434, Aug. 2011, [Peer-reviewed]
English, Scientific journal

Subtropical Pacific SST Variability Related to the Local Hadley Circulation during the Premature Stage of ENSO
Yoshimitsu Chikamoto; Youichi Tanimoto; Hitoshi Mukougawa; Masahide Kimoto
JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN, 88, 2, 183, 202, Apr. 2010, [Peer-reviewed]
English, Scientific journal

A Peculiar Feature of the Seasonal Migration of the South American Rain Band
Youichi Tanimoto; Takushi Kajitani; Hideki Okajima; Shang-Ping Xie
JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN, 88, 1, 79, 90, Feb. 2010, [Peer-reviewed]
English, Scientific journal

Ocean Frontal Effects on the Vertical Development of Clouds over the Western North Pacific: In Situ and Satellite Observations
Hiroki Tokinaga; Youichi Tanimoto; Shang-Ping Xie; Takeaki Sampe; Hiroyuki Tomita; Hiroshi Ichikawa
JOURNAL OF CLIMATE, 22, 16, 4241, 4260, Aug. 2009, [Peer-reviewed]
English, Scientific journal

An Evaluation of Reproducibility of the Pacific Decadal Oscillation in the CMIP3 Simulations
Kazuhiro Oshima; Youichi Tanimoto
JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN, 87, 4, 755, 770, Aug. 2009, [Peer-reviewed]
English, Scientific journal

Observations of Marine Atmospheric Boundary Layer Transitions across the Summer Kuroshio Extension
Youichi Tanimoto; Shang-Ping Xie; Kohei Kai; Hideki Okajima; Hiroki Tokinaga; Toshiyuki Murayama; Masami Nonaka; Hisashi Nakamura
JOURNAL OF CLIMATE, 22, 6, 1360, 1374, Mar. 2009, [Peer-reviewed]
English, Scientific journal

Local and remote influences of the Kuroshio Extension on the atmosphere
Hiroki Tokinaga; Shang-Ping Xie; Fumiaki Kobashi; Youichi Tanimoto
U.S. CLIVAR Variations, 7, 1, 1, 4, 2009
English, Scientific journal

Interannual-to-Decadal Variability in the Oyashio and Its Influence on Temperature in the Subarctic Frontal Zone: An Eddy-Resolving OGCM Simulation
Masami Nonaka; Hisashi Nakamura; Youichi Tanimoto; Takashi Kagimoto; Hideharu Sasaki
JOURNAL OF CLIMATE, 21, 23, 6283, 6303, Dec. 2008, [Peer-reviewed]
English, Scientific journal

Program studies the Kuroshio extension
Kathleen Donohue; D. Randolph Watts; Karen Tracey; Mark Wimbush; Jae-Hun Park; Nicholas Bond; Meghan Cronin; Shuiming Chen; Bo Qiu; Peter Hacker; Nelson Hogg; Steven Jayne; Julie MCClean; Luc Rainville; Humio Mitsudera; Youichi Tanimoto; Shang-Ping Xie
Eos, 89, 17, 161, 162, American Geophysical Union, 22 Apr. 2008, [Peer-reviewed]
English, Scientific journal

Notes and correspondence - Role of SST over the Indian ocean in influencing the intraseasonal variability of the Indian summer monsoon
Mathew Roxy; Youichi Tanimoto
JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN, 85, 3, 349, 358, Jun. 2007, [Peer-reviewed]
English, Scientific journal

Air-sea humidity effects on the generation of tropical Atlantic SST anomalies during the ENSO events
Yoshimitsu Chikamoto; Youichi Tanimoto
GEOPHYSICAL RESEARCH LETTERS, 33, 19, L19702-L19702-6, Oct. 2006, [Peer-reviewed]
English, Scientific journal

Decadal variability in the Kuroshio-Oyashio Extension simulated in an eddy-resolving OGCM
Masami Nonaka; Hisashi Nakamura; Youichi Tanimoto; Takashi Kagimoto; Hideharu Sasaki
JOURNAL OF CLIMATE, 19, 10, 1970, 1989, May 2006, [Peer-reviewed]
English, Scientific journal

Atmospheric sounding over the winter Kuroshio Extension: Effect of surface stability on atmospheric boundary layer structure
H Tokinaga; Y Tanimoto; M Nonaka; B Taguchi; T Fukamachi; SP Xie; H Nakamura; T Watanabe; Yasuda, I
GEOPHYSICAL RESEARCH LETTERS, 33, 4, L04703, L04703, Feb. 2006, [Peer-reviewed]
English, Scientific journal

SST-induced surface wind variations over the Brazil-Malvinas confluence: Satellite and in situ observations
H Tokinaga; Y Tanimoto; SP Xie
JOURNAL OF CLIMATE, 18, 17, 3470, 3482, Sep. 2005, [Peer-reviewed]
English, Scientific journal

Role of Specific Humidity Anomalies in Caribbean SST Response to ENSO
CHIKAMOTO Yoshimitsu; TANIMOTO Youichi
Journal of the Meteorological Society of Japan. Ser. I, 83, 6, 959, 975, Meteorological Society of Japan, 2005, [Peer-reviewed]
English, Scientific journal, Remote influences of El Nino-Southern Oscillation (ENSO) on tropical Atlantic sea surface temperature (SST) are examined using reanalysis and in-situ observational datasets. During both the warm and cold events of ENSO, latent heat flux anomalies are the major mechanism for SST anomalies over the Caribbean Sea. Results from a linear decomposition of the latent heat flux anomalies indicate that the anomalous air-sea difference in specific humidity (Δq´) is the dominant term in January, one month after the ENSO's mature phase. Since anomalies of SST and saturation specific humidity at the sea surface are still small in January, Δq´ is due mostly to changes in specific humidity in the lower atmosphere. Changes in surface air humidity and temperature, and their relationship to temperature variability in the upper troposphere during ENSO warm events are discussed.

A fine view from space
SP Xie; M Nonaka; Y Tanimoto; H Tokinaga; HM Xu; WS Kessler; RJ Small; WT Liu; J Hafner
BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY, 85, 8, 1060, 1062, Aug. 2004, [Peer-reviewed]
English, Scientific journal

Seasonal transition of SST anomalies in the tropical Indian ocean during El Nino and Indian Ocean dipole years
H Tokinaga; Y Tanimoto
JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN, 82, 4, 1007, 1018, Aug. 2004, [Peer-reviewed]
English, Scientific journal

Large-scale interaction among storm tracks, polar-frontjets and midlatitude oceanic fronts
Hisashi Nakamura; Takeaki Sampe; Youichi Tanimoto; Akihiko Shimpo; Wataru Ohfuchi; Shang-Ping Xie
13th Conference on Interactions of the Sea and Atmosphere, 115, 125, 2004
English, International conference proceedings

Observed associations among storm tracks, jet streams and midlatitude oceanic fronts
H Nakamura; T Sampe; Y Tanimoto; A Shimpo
EARTH'S CLIMATE: THE OCEAN-ATMOSPHERE INTERACTION, 147, 329, 345, 2004, [Peer-reviewed]
English, In book

An active role of extratropical sea surface temperature anomalies in determining anomalous turbulent heat flux
Y Tanimoto; H Nakamura; T Kagimoto; S Yamane
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 108, C10, Oct. 2003, [Peer-reviewed]
English, Scientific journal

季節内から数十年スケール気候変動の数値的研究
山崎孝治; 向川 均; 谷本陽一; 石渡正樹; 稲津將; 謝尚平; 岡島秀樹; 奥村夕子
東京大学気候システム研究センター 平成14年度共同研究報告書 pp.101-130, 2003
Japanese, Research society

Direct observations of atmospheric boundary layer response to SST variations associated with tropical instability waves over the eastern equatorial Pacific
H Hashizume; SP Xie; M Fujiwara; M Shiotani; T Watanabe; Y Tanimoto; WT Liu; K Takeuchi
JOURNAL OF CLIMATE, 15, 23, 3379, 3393, Dec. 2002, [Peer-reviewed]
English, Scientific journal

Bathymetric effect on the winter sea surface temperature and climate of the Yellow and East China Seas
SP Xie; J Hafner; Y Tanimoto; WT Liu; H Tokinaga; HM Xu
GEOPHYSICAL RESEARCH LETTERS, 29, 24, Dec. 2002, [Peer-reviewed]
English, Scientific journal

Inter-hemispheric decadal variations in SST, surface wind, heat flux and cloud cover over the Atlantic Ocean
Y Tanimoto; SP Xie
JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN, 80, 5, 1199, 1219, Oct. 2002, [Peer-reviewed]
English, Scientific journal

Tropical Atlantic air-sea interaction and its influence on the NAO
Y Okumura; SP Xie; A Numaguti; Y Tanimoto
GEOPHYSICAL RESEARCH LETTERS, 28, 8, 1507, 1510, Apr. 2001, [Peer-reviewed]
English, Scientific journal

Skeletal isotopic record of a Porites coral during the 1998 mass bleaching event
A Suzuki; H Kawahata; Y Tanimoto; H Tsukamoto; LP Gupta; Yukino, I
GEOCHEMICAL JOURNAL, 34, 4, 321, 329, 2000, [Peer-reviewed]
English, Scientific journal

Pictorial 6 : High-altitude Thermal Inversion in the Southern Slope Area of Mt.Yatsugatake, Central Japan
TANAKA Hiroharu; TANIMOTO Youichi; MIKAMI Takehiko
J. Geogr., 109, 5, 703, 718, Tokyo Geographical Society, 2000, [Peer-reviewed]
Japanese, Scientific journal

How and why climate variability differs between the tropical Atlantic and Pacific
SP Xie; Y Tanimoto; H Noguchi; T Matsuno
GEOPHYSICAL RESEARCH LETTERS, 26, 11, 1609, 1612, Jun. 1999, [Peer-reviewed]
English, Scientific journal

Coral skeletal records : a reconstruction of palaeoceanographic conditions for the last several centuries
SUZUKI Atsushi; TANIMOTO Youichi; KAWAHATA Hodaka
地球化学, 33, 1, 23, 44, 日本地球化学会, Mar. 1999, [Peer-reviewed]
Japanese, Scientific journal, We describe recent progress in palaeo-environmental studies using coral skeletal records. Coral skeletons are excellent archives for considerable and diverse environmental information from tropical oceans. A high precision micro-sampling technique has allowed us to reconstruct high-resolution proxy climate records using the annual density bands of massive corals such as Porites spp. The combination of high-precision oxygen stable isotope analysis and Sr/Ca thermometry is one of the most promising methods for the reconstruction of palaeo-seawater temperature and water budgets including rainf...

Ocean-atmosphere variability over the Pan-Atlantic basin
Y Tanimoto; SP Xie
JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN, 77, 1, 31, 46, Feb. 1999, [Peer-reviewed]
English, Scientific journal

A pan-Atlantic decadal climate oscillation
SP Xie; Y Tanimoto
GEOPHYSICAL RESEARCH LETTERS, 25, 12, 2185, 2188, Jun. 1998, [Peer-reviewed]
English, Scientific journal

Relationships between sea surface temperature, the atmospheric circulation and air-sea fluxes on multiple time scales
Y Tanimoto; N Iwasaka; K Hanawa
JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN, 75, 4, 831, 849, Aug. 1997, [Peer-reviewed]
English, Scientific journal

Examination of the strengthening of wintertime mid-latitude westerlies over the North Pacific in the 1970s
K Hanawa; S Ishizaki; Y Tanimoto
JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN, 74, 5, 715, 721, Oct. 1996, [Peer-reviewed]
English, Scientific journal

STATIC RELATIONSHIP BETWEEN ANOMALIES OF SSTS AND AIR-SEA HEAT FLUXES IN THE NORTH PACIFIC
K HANAWA; R SANNOMIYA; Y TANIMOTO
JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN, 73, 3, 757, 763, Jun. 1995, [Peer-reviewed]
English, Scientific journal

CHARACTERISTIC VARIATIONS OF SEA-SURFACE TEMPERATURE WITH MULTIPLE TIME SCALES IN THE NORTH PACIFIC
Y TANIMOTO; N IWASAKA; K HANAWA; Y TOBA
JOURNAL OF CLIMATE, 6, 6, 1153, 1160, Jun. 1993, [Peer-reviewed]
English, Scientific journal

Variations with multiple time scales on the global sea surface tempreture fields and their relationship with the atmospheric general circulation.
TANIMOTO Y.
Doctral Thesis, 116, Tohoku University, 1993
English, Others

冬季モンスーンと大気海洋相互作用—気候系のHotspot : 中緯度大気海洋相互作用研究の新展開
高谷 康太郎; 西井 和晃; 中村 尚; 升永 竜介; 谷本 陽一; 佐藤 友徳; 小池 真; 浅野 匠彦, 気象研究ノート, 244, 325, 339, Oct. 2021
日本気象学会, Japanese

黒潮続流南方海域における冷水渦に関係した海洋混合層と亜表層の水温変化-アルゴフロート観測データ解析-
長谷川拓也; 長谷川拓也; 細田滋毅; 植原量行; 谷本陽一; 谷本陽一, 日本海洋学会大会講演要旨集, 2020, 2020

南北両半球で同時発生する熱帯太平洋東部域の海洋ロスビー波
阿部泰人; 谷本陽一; 谷本陽一; 長谷川拓也; 江淵直人, 日本海洋学会大会講演要旨集, 2016, 63, Mar. 2016
Japanese

B154 季節予測モデルにおけるITCZ変動に伴う大気海洋変動場の再現性(気候システムII,一般口頭発表)
安田,珠幾; 卜部,佑介; 前田,修平; 谷本,陽一; 高谷,祐平; 松川,知紘; 久保,勇太郎; 石川,一郎; 杉本,裕之; 松枝,聡子, 大会講演予講集, 108, 126, 30 Sep. 2015
日本気象学会, Japanese

B155 東部熱帯太平洋の海面水温偏差場に見られる南北ダイポールの年々変動特性(気候システムII,一般口頭発表)
谷本 陽一; 卜部 佑介; 前田 修平, 大会講演予講集, 108, 127, 127, 2015
日本気象学会, Japanese

B152 2014年のエルニーニョ現象の成長を抑制した強いITCZ(気候システムII,一般口頭発表)
前田 修平; 卜部 佑介; 竹村 和人; 安田 珠幾; 谷本 陽一, 大会講演予講集, 108, 124, 124, 2015
日本気象学会, Japanese

B153 SVD解析によるITCZの主要変動パターンの抽出(気候システムII,一般口頭発表)
卜部 佑介; 安田 珠幾; 前田 修平; 谷本 陽一, 大会講演予講集, 108, 125, 125, 2015
日本気象学会, Japanese

黒潮・親潮続流域における複数の水温前線が冬季大気境界層に及ぼす影響
中村尚; 升永竜介; 宮坂貴文; 西井和晃; 谷本陽一; QIU Bo, 日本海洋学会大会講演要旨集, 2014, 26, 01 Sep. 2014
Japanese

黒潮・親潮続流域における複数の水温前線が冬季の大気境界層に及ぼす影響
升永竜介; 中村尚; 宮坂貴文; 西井和晃; 谷本陽一; QIU Bo, 日本気象学会大会講演予稿集, 105, 72, 30 Apr. 2014
Japanese

熱帯収束帯の南北変位により励起された海洋ロスビー波
阿部泰人; 谷本陽一; 長谷川拓也; 江淵直人; 花輪公雄, 日本海洋学会大会講演要旨集, 2014, 99, 10 Mar. 2014
Japanese

黒潮・親潮海洋前線に伴う海面気圧極小と地表傾圧帯に見られる経年変動~大気再解析データで表現される大気境界構造の海面水温データへの依存性~
升永竜介; 中村尚; 宮坂貴文; 西井和晃; 谷本陽一, 日本気象学会大会講演予稿集, 103, 103, 355, 355, 30 Apr. 2013
日本気象学会, Japanese

黒潮・親潮続流域に形成される海面気圧極小と傾圧帯の経年変動
升永 竜介; 中村 尚; 宮坂 貴文; 西井 和晃; 谷本 陽一, 週間及び1か月予報における顕著現象の予測可能性, 42, 46, Mar. 2013
平成24年度京都大学防災研究所一般研究集会(24K-08)「週間及び1か月予報における顕著現象の予測可能性」, 京都大学防災研究所連携研究棟大セミナー室, 2012/11/20-22, Japanese

中緯度西岸域における大気海洋相互作用
谷本陽一, 天気, 59, 9, 762, 768, 30 Sep. 2012
Japanese

P402 CMIP3マルチ気候モデルにおける冬季北太平洋の海面気圧トレンドにみられる地域差とその不確実性(ポスター・セッション)
大島 和裕; 谷本 陽一; 謝 尚平, 大会講演予講集, 99, 395, 395, 2011
日本気象学会, Japanese

A361 CMIP3マルチ気候モデルを用いた北太平洋における大気・海洋の将来変化(気象システムIII,,一般口頭発表)
大島 和裕; 末吉 雅和; 安田 珠幾; 岡田 靖子; 谷本 陽一; 謝 尚平, 大会講演予講集, 100, 104, 104, 2011
日本気象学会, Japanese

P131 北太平洋の海面水温場に見られる10年規模変動と温暖化トレンドの空間パターン : CMIP3マルチ気候モデルによる実験結果を用いた解析(ポスターセッション)
大島 和裕; 谷本 陽一, 大会講演予講集, 97, 248, 248, 2010
日本気象学会, Japanese

A365 CMIP3マルチ気候モデルにおける環太平洋域の内部変動と温暖化トレンドの比較(スペシャル・セッション「マルチ気候モデルデータ解析による地球温暖化現象の理解」,口頭発表)
大島 和裕; 谷本 陽一, 大会講演予講集, 98, 106, 106, 2010
日本気象学会, Japanese

A363 大西洋赤道冷水舌が南アメリカ降水帯に与える影響 : 気候モデルにおける再現性(スペシャル・セッション「地球温暖化に伴う大気海洋諸現象の変化を考える-CMIP3マルチ気候モデル比較解析研究から-」)
谷本 陽一; 梶谷 卓志; 岡島 秀樹; 大島 和裕; 謝 尚平, 大会講演予講集, 96, 97, 97, 2009
日本気象学会, Japanese

A306 CMIP3気候モデルにおける北太平洋10年規模変動の将来予測(気候システムII)
大島 和裕; 谷本 陽一, 大会講演予講集, 95, 70, 70, 2009
日本気象学会, Japanese

On the importance of oceanic frontal zones in extratropical ocean-atmosphere interaction
中村 尚; 谷本 陽一; 根田 昌典, Kaiyo monthly, 49, 5, 11, 2008
海洋出版, Japanese

Variation of marine atmospheric boundary layer ovserved over the winter Kuroshio Extension
小橋 史明; 谷本 陽一; 岩坂 直人, Kaiyo monthly, 49, 49, 56, 2008
海洋出版, Japanese

Estimation of surface air specific humidity using satellite data over the Kuroshio Extension region
富田 裕之; 時長 宏樹; 谷本 陽一, Kaiyo monthly, 49, 93, 99, 2008
海洋出版, Japanese

Modifications of marine atmospheric boundary layer across summer Kuroshio Extension
谷本 陽一; 謝 尚平; 甲斐 浩平, Kaiyo monthly, 49, 42, 48, 2008
海洋出版, Japanese

P325 黒潮続流域における中規模SST偏差の総観規模擾乱への影響
古関 俊也; 渡部 雅浩; 谷本 陽一; 謝 尚平, 大会講演予講集, 93, 436, 436, 2008
日本気象学会, Japanese

B466 CMIP3モデルにおける北太平洋10年規模変動の再現性(CMIP3マルチ気候モデルにおける大気海洋諸現象の再現性比較,専門分科会)
大島 和裕; 谷本 陽一, 大会講演予講集, 93, 186, 186, 2008
日本気象学会, Japanese

A103 冬季黒潮続流域で観測された大気境界層の構造と変動(相互作用)
小橋 史明; 谷本 陽一; 村山 利幸; 岩坂 直人; 時長 宏樹; 野中 正見; 根田 昌典, 大会講演予講集, 91, 33, 33, 2007
日本気象学会, Japanese

A258 親潮の経年/十年規模変動と亜寒帯前線域の海面水温変動(太平洋・インド洋域における大気海洋結合現象,専門分科会)
野中 正見; 中村 尚; 谷本 陽一; 鍵本 崇; 佐々木 英治, 大会講演予講集, 89, 57, 57, 2006
日本気象学会, Japanese

黒潮続流域における大気直接観測 (総特集 夏季気候変動--冷夏猛暑に代表される夏季異常気象研究の統合) -- (2章 ヤマセ)
谷本 陽一; 時長 宏樹; 甲斐 浩平, 海洋. 号外, 44, 75, 80, 2006
海洋出版, Japanese

西部北太平洋における十年規模変動と親潮の経年変動--高解像度海洋大循環モデルOFESによる研究 (総特集 北太平洋における表層水塊過程) -- (1章 西部亜寒帯循環の変動と水塊)
野中 正見; 中村 尚; 谷本 陽一, 海洋. 号外, 43, 19, 34, 2006
海洋出版, Japanese

P196 Brazil-Malvinas Confluenceにおける海面水温分布に対する下層大気循環の応答
時長 宏樹; 谷本 陽一; 謝 尚平, 大会講演予講集, 88, 393, 393, 2005
日本気象学会, Japanese

Report on the XXIII General Assembly of the International Union of Geodesy and Geophysics : (IUGG2003)(2)
MOCHIZUKI Takashi; TANIMOTO Youichi; TOZUKA Tomoki; SUZUKI Rieko; MIYASAKA Takafumi; IKEDA Motoyoshi; YANAGI Tetsuo; MORI Atsushi; NIINO Hiroshi; IWAYAMA Takahiro; IGA Keita; AKIYOSHI Hideharu; MASUDA Kooichi; MIYAZAKI Shin; OKAMOTO Hajime; TSUSHIMA Yoko; KAWAMOTO Kazuaki; TAKEMURA Toshihiko; SUDO Kengo; HONDA Meiji; ARAI MIki; SAKAMOTO Kei; MABUCHI Kazuo; TAKAHASHI Kenshi; HASHIGUCHI Hiroyuki; MURAKAMI Shigenori, 天気, 51, 4, 241, 260, 30 Apr. 2004
日本気象学会, Japanese

D311 冬季黒潮続流における海面水温フロント上でのGPSラジオゾンデ観測(相互作用)
時長 宏樹; 谷本 陽一; 野中 正見; 田口 文明; 深町 知宏; 謝 尚平; 中村 尚; 渡邊 朝生; 安田 一郎, 大会講演予講集, 86, 362, 362, 2004
日本気象学会, Japanese

C464 中緯度の海面水温の長期変動が下層大気に与える影響 : 最近の観測的研究から(ストームトラックの力学,専門分科会)
谷本 陽一; 中村 尚; 時長 宏樹; 鍵本 崇; 山根 省三, 大会講演予講集, 85, 163, 163, 2004
日本気象学会, Japanese

C461 中緯度のストームトラック,偏西風,海洋フロントの相互関係(ストームトラックの力学,専門分科会)
中村 尚; 三瓶 岳昭; 新保 明彦; 尾上 良範; 谷本 陽一; 謝 尚平, 大会講演予講集, 85, 160, 160, 2004
日本気象学会, Japanese

JSP01: The Decadal to Centennial Variability of the Ocean and Atmosphere(第23回IUGG/IAPSO総会報告)(集会報告)
望月 崇; 谷本 陽一; 見延 庄士郎; 地球フロンティア; 北大院地球環境 : 地球フロンティア; 北大院理 : 地球フロンティア, 海の研究 = Umi no Kenkyu (Oceanography in Japan), 12, 6, 629, 629, 05 Nov. 2003
Japanese

B363 ENSO時におけるカリブ海周辺の潜熱フラックス変動とその要因(気候システムIII)
近本 喜光; 谷本 陽一, 大会講演予講集, 84, 156, 156, 2003
日本気象学会, Japanese

D162 線形化海面フラックスデータを用いた大気海洋相互作用の研究(歴史的海上気象観測データ(神戸コレクション)のデジタル化と研究の展望)
谷本 陽一; 中村 尚; 鍵本 崇; 山根 省三, 大会講演予講集, 83, 200, 200, 2003
日本気象学会, Japanese

El NinoおよびLa Ninaに対する大西洋大気海洋結合系の応答
近本 喜光; 谷本 陽一, 大会講演予講集, 81, 369, 369, May 2002
Japanese

インド洋ダイポール現象と熱帯太平洋大気海洋変動との季節的な関係
時長 宏樹; 谷本 陽一, 大会講演予講集, 81, 268, 268, May 2002
Japanese

Pan-Atlantic Decadal Oscillation
TANIMOTO Youichi, 天気, 49, 10, 811, 818, 2002
日本気象学会, Japanese

大西洋のInter-hemispheric 10年スケール気候変動 (総特集 大規模大気海洋相互作用--数十年スケール変動の実態と機構) -- (2章 大西洋セクターにおける長期変動)
谷本 陽一, 号外海洋, 24, 108, 115, 2001
海洋出版, Japanese

Inter-Hemisphere Decadal Variations in SST, surface wind and heat flux over the Atlantic basin
谷本 陽一; 謝 尚平, Technical reports of Japan Marine Science and Technology Center, 41, 57, 68, Mar. 2000
海洋科学技術センタ-, English

10.JSP25:海洋/大気の変動性と予測可能性(第22回国際測地学地球物理学連合総会(IUGG99)報告(2))
谷本 陽一; 根田 昌典; 渡部 雅浩; 中村 尚; 見延 庄士郎, 天気, 47, 2, 103, 104, 29 Feb. 2000
社団法人日本気象学会, Japanese

A Report on the Symposium on Digitized Kobe Collection : New Aspects of Ocean and Climate Studies Activated by Digitization of Historical Marine Meteorological Data
花輪 公雄; 眞鍋 輝子; 山元 龍三郎; 岡田 弘三; 石井 正好; 安田 一郎; 見延 庄士郎; 谷本 陽一; 岩坂 直人; 京都大学:日本気象協会関西本部, 海の研究 = Umi no Kenkyu (Oceanography in Japan), 8, 4, 285, 289, 05 Aug. 1999
日本海洋学会, Japanese

「デジタル化されたKobe Collection -歴史的海上気象資料がもたらす海洋・気候研究の新展開-」
花輪公雄; 眞鍋輝子; 山元龍三郎; 岡田弘三; 石井正好; 安田一郎; 見延庄士郎; 谷本陽一; 岩坂直人, 海の研究, 8, 4, 285, 289, 05 Aug. 1999
日本海洋学会, Japanese, Introduction other

Temporal Structure of coral proxy for sea surface temperature in the tropics
TANIMOTO Youichi; ICHINO Mika; SUZUKI Atsushi, 日本地理学会発表要旨集 = Proceedings of the General Meeting of the Association of Japanese Geographers, 54, 150, 151, Sep. 1998
Japanese

4.全球海洋における10年スケール変動(月例会「長期予報と大気大循環」の報告)
谷本 陽一, 天気, 41, 2, 116, 116, 1994
Japanese

大気・海洋相互作用とエル・ニーニョ，モンスーン，，「地球惑星科学入門」第28章
谷本陽一
北海道大学出版会, 2010, [Joint work]

Oceans and Atmosphere. Oceanography Basics
Youichi Tanimoto
UNESCO International Hydrological Programme, 2007, [Joint work]

UNIX/Windowsを使った実践気候データ解析 : 気候学・気象学・海洋学などの報告書・論文を書く人が知っておきたい3つのポイント
松山 洋; 谷本 陽一
古今書院, 2005, 4772240578, Japanese

気候変動 : 多角的視点から
Burroughs William James; 松野 太郎; 大淵 済; 谷本 陽一; 向川 均
シュプリンガー・フェアラーク東京, 2003, 9784431710592, Japanese

Vertical structures in temperature and momentum in the atmospheric boundary layer along SST front
Youichi Tanimoto
Sixth China-Korea-Japan Joint Conference on Meteorology, 24 Oct. 2013, English, Oral presentation
Nanjing, セッションコンビナー 座長, [International presentation]

黒潮続流上における大気下層の調節過程
谷本陽一
日本気象学会2012年春季大会専門分科会 「東アシアモンスーンと黒潮(II) ―中緯度大気海洋相互作用に着目した新たな研究のハラタイム」, 26 May 2012, Japanese, Invited oral presentation
[Invited], [Domestic Conference]

気候変動特論, 2024年, 修士課程, 環境科学院

環境と人間, 2024年, 学士課程, 全学教育

Extratropical climate variability and change bi-directionally interacting with the tropics and polar regions
Grants-in-Aid for Scientific Research
01 Apr. 2024 - 31 Mar. 2029
時長 宏樹; 小川 史明; 山本 絢子; 森 正人; 望月 崇; 谷本 陽一
Japan Society for the Promotion of Science, Grant-in-Aid for Transformative Research Areas (A), Kyushu University, 24H02229

気候の過渡的応答を規定する海洋中規模渦による海洋熱吸収の全球定量化
科学研究費助成事業
01 Apr. 2023 - 31 Mar. 2026
谷本 陽一; 富田 裕之; 木戸 晶一郎
高解像度海洋再解析データを利用し、北太平洋の海洋中規模渦上で行われた大気と海洋の熱交換に焦点を当てた研究を実施した。本研究では、渦を個別にトラッキングする従来のラグランジュ的手法ではなく、各格子点の流速データから求められる曲率渦度に基づき、高気圧性・低気圧性の中規模渦をオイラー的に抽出する手法を高解像度海洋再解析データに適用することを試みた。抽出された高気圧(低気圧)性回転を示すグリッドでの海面水温は、85%以上の割合で長期間の時間平均場に対する正(負)偏差を示した。また、高気圧性・低気圧性回転それぞれでコンポジットした水温偏差は、暖水渦・冷水渦に特徴的な渦の中心から概ね同心円状に分布する水温偏差の水平・鉛直構造を適切に再現し、本研究の手法が暖水渦・冷水渦を高解像度海洋再解析データから適切に取り出せることを示した。
さらに、中規模渦が検出されたグリッドとそうでないグリッドの海面熱フラックスを比較した結果、高気圧性(低気圧性)渦上では下向き(上向き)の海面熱フラックス偏差が示された。高気圧性(低気圧性)渦の存在頻度は中緯度の水温フロントの高緯度(低緯度)側で大きいため、中規模渦に伴う大気海洋熱交換は高緯度(低緯度)側での海洋からの熱放出を促進(抑制)し、結果として海水温の緯度分布を維持する働きを持つことが示された。このような海洋中規模渦に伴う大気海洋熱交換偏差は、1993年から2021年の間に北西部太平洋で吸収された熱量の約20%に相当すると見積もられた。
日本学術振興会, 基盤研究(B), 北海道大学, 23K25935

気候の過渡的応答を規定する海洋中規模渦による海洋熱吸収の全球定量化
科学研究費助成事業
01 Apr. 2023 - 31 Mar. 2026
谷本 陽一; 富田 裕之; 木戸 晶一郎
日本学術振興会, 基盤研究(B), 北海道大学, 23H01239

Extratropical air-sea interaction that can potentially influence atmospheric anomalies and their predictability
Grants-in-Aid for Scientific Research
28 Jun. 2019 - 31 Mar. 2024
中村 尚; 谷本 陽一; 河谷 芳雄; 高薮 縁; 山崎 哲; 西井 和晃; Martineau Patrick
1）降水観測データと大気再解析データから，西日本に広域豪雨に特徴的な水蒸気輸送や大規模大気循環場を同定した．2) 大気再解析データに基づく流跡線解析から，北東大西洋上空に形成されるブロッキング高気圧について，メキシコ湾流や黒潮続流からの熱・水蒸気供給とその後の降水に伴う上昇運動が，低渦位の高気圧性空気塊を上空のブロッキング高気圧内に供給するのに不可欠なことを見出した．3）南半球中緯度域の移動性高・低気圧活動が半球規模で変動する「傾圧環状モード」が卓越する要因として，中緯度海洋前線の影響による移動性高・低気圧の発達強化が重要なことを大気大循環モデル実験から明らかにした．4) 南インド洋の亜熱帯高気圧（マスカリン高気圧）の特徴的な季節変化を大気再解析データと衛星観測データの解析，及び数値モデル実験から解明した．即ち，日射の強い夏季には，高気圧東縁の下降気流や寒気移流の下で形成される下層雲が日射を反射して海面水温を低下させ，対流性雲を抑制することが本質的に重要である一方，この効果が弱まる冬季には，南西インド洋域のアガラス海洋前線に伴って繰り返し発達する移動性高低気圧からの熱・運動量フラックスを通じたフィードバック強制やアジアモンスーンからの遠隔影響により海盆西側で強化される．5) 移動性擾乱に伴う風・温度・気圧の変動や熱・運動量フラックス，及びそれらを通じた背景場とのエネルギー変換について，流れ場の曲率に着目した高気圧・低気圧別の評価を可能とする診断法を開発した．これは，渦中心の経路追跡に基づくラグランジュ的統計の長所を定量的な力学診断に有効なオイラー的擾乱解析に取り込んだ世界初の画期的な手法である．
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area), The University of Tokyo, 19H05702

大気海洋系内の熱フローの理解に立脚した地球温暖化の加速・減速の要因解明
科学研究費助成事業
01 Apr. 2018 - 31 Mar. 2022
谷本 陽一; 富田 裕之; 細田 滋毅; 時長 宏樹; 野中 正見; 植原 量行
海洋熱吸収の10年規模変動成分と、海洋中規模渦が海洋熱吸収に果たす役割に焦点を当てた研究を実施した。過去の海洋プロファイリングフロート（以下、フロート）観測に基づく水温・塩分データセットの解析から、海洋の表層および亜表層の貯熱量が2008年から2015年の期間では北太平洋全体で減少し、2016年から2018年の期間では増加することが分かった。また、渦解像大循環海洋モデルの経年変動シミュレーション出力を解析した結果、北太平洋中央部において、海洋表層下へ取り込まれた熱が海洋中規模渦の影響で南北方向に広く拡張することが示された。以上から、海洋亜表層に至る熱吸収の存在が示唆され、この海洋熱吸収に海洋中規模渦が影響を与える可能性が見出された。
さらに、海面熱フラックスを用いて海面における大気と海洋の熱交換に関して調べた。その結果、北太平洋の広範囲において10年規模の海面熱フラックスの変動が海面水温変化によって説明できることがわかった。くわえて、精度の高い海面熱フラックスデータの作成にむけて、人工衛星観測に基づく全球海面熱フラックス変動の不確定性に関する研究も実施した。
今年度末には、昨年度から準備を進めていたフロートによる現場観測を開始した。研究目的に適合する仕様を有するフロートを３基購入し、海洋中規模渦に捕捉されやすいようにフロートの制御パラメータを変更した。その後に、黒潮続流域南方海域において、気象庁の協力を得て、海洋中規模渦の一種である冷水渦の領域に３基のフロートを凌風丸から投入した。投入した３基のフロートはそれぞれ11回の浮上を本年度中に行い、合計３３個の水温プロファイルおよび同数の塩分プロファイルを取得した。投入時に凌風丸によって実施された船舶観測CTDデータと比較することによって、３基のフロートが正常に水温・塩分データを取得している点を確認した。
日本学術振興会, 基盤研究(A), 北海道大学, 18H03726

A study on the interaction among multi-layer cloud, radiation, precipitation, and ocean mixed layer
Grants-in-Aid for Scientific Research
01 Apr. 2016 - 31 Mar. 2019
Hayasaka Tadahiro
A comprehensive analysis was performed using various satellite observation data, reanalysis data, ship observation data, and Argo float observation data. In addition, the simulation of the relationship between sea surface temperature and clouds was performed using the regional meteorological model WRF. As a result, it was shown that the low clouds in the summer North Pacific, which have been analyzed from relatively simple viewpoints such as sea surface temperature and atmospheric stability, have different fine structures in the western and central regions. In the western part of the North Pacific Ocean, the Kuroshio and Kuroshio Extension are dominant, and cloud fluctuations have little effect on the sea. On the other hand, in the central part of the North Pacific Ocean, it is suggested that the ocean mixing layer is shallow and the sea surface temperature affects the clouds, but the fluctuation of the clouds also influences the ocean mixing layer.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Tohoku University, 16H04046

Surface wind adjustment and its feedback to the ocean surface layers over the gyre boundary regions
Grants-in-Aid for Scientific Research
01 Apr. 2015 - 31 Mar. 2018
TANIMOTO Youichi
Surface wind adjustment and its feedback to the ocean surface layers over the gyre boundary regions are examined. We found that the wind adjustment process in the extratropics acts as suppressed cooling via vertical mixing and entrainment changes. In the boundary region across the equatorial and subtropical gyres, the vorticity input to the ocean exhibits rich horizontal structures, owing to the horizontal wind shear and a meridional change in the Coriolis parameter. The forced ocean surface layers show the Rossby wave and its propagations, which is associated with the interannual variability for the El Nino-Southern Oscillation and with the decadal variations for the Indonesian Throughflow.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 15K05279

Indirect effects of anthropogenic aerosols in East Asia
Grants-in-Aid for Scientific Research
01 Apr. 2014 - 31 Mar. 2018
KOIKE Makoto
By serving as cloud condensation nuclei, aerosols affect cloud microphysics, and as a consequence, they can affect cloud albedo, cloud amount, and precipitation. In this study we show using satellite-derived cloud data that cloud droplet number concentration increases over the East China sea where the Kuroshio ocean current with high sea surface temperature (SST) is located especially when cold air outbreak takes place. We also show using aircraft data that aerosol number concentration and vertical structure of cloud liquid water content are very different in precipitating clouds as compared with those in non-precipitating clouds. Using improved numerical models, we show that these observed features of influences of aerosols and SST on clouds and precipitation can be successfully reproduced.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), The University of Tokyo, 26241003

In situ observations of air-sea interaction in the Kuroshio-Oyashio Extension region
Grants-in-Aid for Scientific Research
01 Apr. 2010 - 31 Mar. 2015
KAWAI Yoshimi; TANIMOTO Youichi; ITO Shin-ichi; TOMITA Hiroyuki; OKA Eitarou; SUGA Toshio; KOBASHI Fumiaki; UEHARA Kazuyuki; NAGANO Akira; KOBAYASHI Taiyo; ENOMOTO Takeshi; KURODA Hiroshi; TACHIBANA Yoshihiro; KONDA Masanori; INOUE Ryu-ichiro; FAURE Vincent; MOTEKI Qoosaku; TANIGUCHI Kyoko
Intensive atmosphere-ocean observations were conducted in the Kuroshio-Oyashio Extension region using research vessels and a moored buoy in order to clarify impacts of the sea surface temperature fronts on the atmosphere, and formation and maintenance processes of the oceanic fronts and water masses.
We showed that both the Kuroshio Extension front in early summer (Baiu/Meiyu season) and the Subarctic front in late winter caused differences in height of the atmospheric boundary layer and low-level clouds across the fronts, as well as cross-frontal pressure gradients. We also clarified variations of water mass transport and nutrients in the surface layer caused by the quasi-stationary jet. Our observations also captured temporal changes of the wintertime ocean mixed layer on a short time scale, and transportation of subarctic water masses to the south of the Kuroshio Extension.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area), Japan Agency for Marine-Earth Science and Technology, 22106007

Mechamisms of two-way interactions between the East Asian Monsoon variability and the Kuroshio Current/Kuroshio Extension
Grants-in-Aid for Scientific Research
01 Apr. 2010 - 31 Mar. 2015
KAWAMURA Ryuichi; IIZUKA Satoshi; SATO Naoki; TOMITA Tomohiko; WATANABE Masahiro; TANIMOTO Youichi; MATSUMOTO Jun; KAWANO Tetsuya
Using both various observational data and high-resolution numerical models on regional and global scales, we clarified (1) the passive and active roles of the Kuroshio Current/Kuroshio Extension in extratropical cyclone activities in the winter monsoon regions, (2) the significant contribution of the SST increase over the Kuroshio Current/Kuroshio Extension to the increases in wintertime rainfall along the Pacific coast and associated cyclone activity, (3) the interaction between the SST front intensification and low-level westerlies along the Baiu frontal zone, (4) how the typhoons have the potential to accumulate large amounts of moisture from distant tropical oceans, and also assessed (5) how the SST increase over the Japan Sea impacts the wintertime rainfall variability and summertime heavy rainfall events in northern Japan.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area), 22106005

気候系のhot spot：熱帯と寒帯が近接するモンスーンアジアの大気海洋結合変動
科研費
Apr. 2010 - Mar. 2015
中村尚
JSPS, Competitive research funding

中緯度大気海洋系10年スケール変動の再現性とその将来変化に関する研究
地球環境研究総合推進費
Apr. 2007 - Mar. 2012
谷本陽一
環境省, Principal investigator, Competitive research funding

Ocean front effects on development and maintenance of the synoptic low pressure and its feedback to the ocean surface layers.
Grants-in-Aid for Scientific Research
2010 - 2012
TANIMOTO Youichi; NAKAMURA Hisashi; TAGUCHI Bunmei; KOMORI Nobumasa; SHIMOYAMA Kou
Ocean-to-atmosphere effects are examined in the sea surface temperature (SST) frontal region along Kuroshio-Kuroshio Extension south of Japan. A wedge-shaped low sea level pressure (SLP) is found over the region with intense surface heat fluxes along the front. In the numerical experiments, the model forced by the prescribed SST with the front successfully reproduced the observed features. By contrast, the model forced by the smoothed SST failed to reproduce the features. These observational and numerical results show that the heat release from the ocean warms up the lower atmosphere and then form SLP minimum over that region as the hydrostatic adjustments.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, Principal investigator, Competitive research funding, 22340132

黒潮と親潮上における大気海洋相互作用
住友財団研究助成
Apr. 2004 - Mar. 2007
谷本陽一
住友財団, Principal investigator, Competitive research funding

Ocean-atmosphere interaction over sea surface temperature front along Kuroshio Extension and North Pacific subtropical front.
Grants-in-Aid for Scientific Research(基盤研究(B))
2005 - 2007
Youichi TANIMOTO; 中村 尚; 小橋 史明
Over the western North Pacific east of the Japan, sea surface temperature (SST) shows a steep front across the Kuroshio Extension (KE). The SST gradient near the KE is 5℃/200 km through seasons, therefore changes in SST are very large in that region. In the present study, we conducted global positioning system (GPS) radio sonde atmospheric soundings across the front in July 2005 (January 2006) as a research cruise of research vessel (R/V) Roger Revelle, Scripps Institute of Oceanography (R/V Hakuho-maru, Ocean Research Institute, University of Tokyo).In early summer, whilst the lower atmosp...
Ministry of Education, Culture, Sports, Science and Technology, 基盤研究(B), 北海道大学, Principal investigator, Competitive research funding, 17340137

Roles of airsea and land-air interactions on East Asian monsoon variability during transition seasons
Grants-in-Aid for Scientific Research(基盤研究(C))
2003 - 2004
Youichi TANIMOTO; 渡部 雅浩; 山崎 孝治
We examined thermal and dynamical structures of the lower atmosphere over the extratropical temperature front near Kuroshio extension and Oyashio where the deformation scale is less than a few of 100km. In addition, we also see the relation of sea surface temperature (SST) and surface air temperature to the surface wind velocity not only in the extratropics, but also tropics for the comparison. Over the warm flank of the thermal front near Kuroshio extension, the planetary boundary layer develops to 1000-1500m height because the static stability near the surface is very unstable. This unsta...
Ministry of Education, Culture, Sports, Science and Technology, 基盤研究(C), 北海道大学, Principal investigator, Competitive research funding, 15540416

サンゴ骨格の分析による新しいトレーサーの開発
科学研究費助成事業
1997 - 1998
塚本 すみ子; 谷本 陽一
小笠原諸島父島はエルニーニョ現象の鍵を握る西太平洋暖水塊の北端にあたり,この海域のサンゴ年輪試料を用いて過去の海面水温や塩分の復元をおこなうことは,気候変動の研究において重要な意味をもつ.しかしサンゴの生育環境は島に近接した浅海底であり,サンゴ骨格に記録された水温・塩分などの指標が必ずしも外洋の環境と一致していない恐れがある.このことを検証するため,昨年度は父島宮乃浜の塊状ハマサンゴの近傍に水温・塩分測定装置(アレック電子製・MDS-CT)を設置した.今年度は,データの回収および宮乃浜のハマサンゴ骨格のコア採取のための現地調査を行った.
サンゴコア採取は,小笠原諸島が国立公園に指定されており,通常の油圧式のコアラーを用いたコア採取が望ましくないことから,コンプレッサーからの圧縮空気を用いてコアラーを回転させるエアドリルを使用した.2つのハマサンゴ群体について,それぞれ70cm,140cmの2本のコアが採取できた.
しかし水温・塩分データに関しては,昨年記録的な台風に見回れたためか,回収した測器が浸水しており,全くデータを回収することができなかった.このため,実測した水温・塩分とサンゴの記録の比較を行うという当初の計画は変更せざるを得なくなった.
そこで98年12月に測器を修理後,浸水対策を十分に行って再び宮乃浜にMID-CTを設置した.また既存の海面水温データを,東京都立小笠原水産センターから入手した.これは父島二見湾で1974年1月から現在まで毎日測定されたものである.このデータと採取されたサンゴの水温日変化の記録がどの程度対応しているのかについて現在分析を進めている.
今回の研究では,設置した測器のデータ回収に失敗したため,予定の2年間で研究を終了することができなかったが,当初計画していた水温・塩分の実測値とサンゴの記録の比較についてもデータが回収出来次第,行う予定である.
日本学術振興会, 萌芽的研究, 東京都立大学, 09874109

大気海洋間熱フラックスが大気大循環における長期変動の形成・維持に及ぼす効果の解明
科学研究費補助金(奨励研究(A))
1997 - 1998
谷本 陽一
気候変動に対する海洋の役割を解明するためには,大気海洋相互作用の実態を明らかにする必要がある.数値モデルによる大気海洋間の熱・運動量の交換には未だ問題があり,人為的に調整をして数値実験を行っているに過ぎない.これらの問題を解決するには,全球海洋における海面熱フラックスの研究を観測面から充実させる必要があった.本研究では,全球海洋における海上気象要素の観測値を整備し,旬平均緯度経度2度格子の海上気象要素ー海面熱フラックス・運動量フラックスのデータセットを1950年から1995年にわたって整備した.実測値に基づいたデータセットを用い,環大西洋域における10年スケール変動について詳しく調べた.熱帯における海面水温場は10年スケール(8-16年)と年々変動(5年以下)のスケールに分離された.10年スケール変動では,海面水温の強い南北傾度が北緯15度と南緯15度付近の間に現れた.一方,年々変動では熱帯全域で同符号の変動を示し南北傾度はほとんど示されなかった.熱帯の強い南北傾度に対する海面気圧場・海面水温場の回帰係数は中高緯度へのテレコネクションを示した.特に北半球の気圧場ではNorth Atlantic Oscillation(NAO)と関連していた.熱帯海面水温の強い南北傾度に伴うラグ回帰は,中高緯度の海面気圧アノマリが南北半球間でほぼ逆位相の関係を持ち10年スケール規模で変動してい...
文部科学省, 奨励研究(A), 東京都立大学, Principal investigator, Competitive research funding, 09740367