基本情報

所属

• 理学研究院　地球惑星科学部門　地球惑星ダイナミクス分野

職名

• 教授

学位

• 博士 (理学)

ホームページURL

https://www.sci.hokudai.ac.jp/~minobe/

ORCID ID

•  https://orcid.org/0000-0002-9487-9006

Researcher ID

• E-2997-2010

J-Global ID

• 200901033473487334

プロフィール

• 大気と海洋の相互作用，大気海洋の変動の研究をしています．研究範囲は海洋学・気象学・気候学ということになり，海外では影響力のある論文が気象学の論文であるため気象学者と思われており，もともとを大事にする日本では，海洋学者と思われているようです．気候学については本来両者の垣根は低いはずで，日本でもJpGUが旧来の学会の垣根を越えて集まれるようになっています．
  
  
  ここに入れている論文はWeb of Scienceからインポートできる査読論文にほぼ限定されています．また講演は，ほぼ招待講演に限定しています．
  
  
  大気海洋の研究に加えて，論理的な思考・文書執筆を重視しており，企業で「理系文書の書き方」の講座を行ったこともあります．

研究キーワード

• 同期   栄養塩   地球シミュレーター   最適内挿法   溶存酸素   接地境界層   大気数値モデル   非静水圧3次元数値実験   気候レジームシフト   非線形共鳴   非線形同期   レジーム・シフト   オホーツク海   pH   数値実験   気候力学   降水帯   高解像度   黒潮   メキシコ湾流   データ解析   アリュ-シャン低気圧   50〜70年スケ-ル   親潮   海氷   衛星データー   気候変動   十年スケール変動   北太平洋   大気海洋相互作用   

研究分野

• 環境・農学 / 環境動態解析
• 自然科学一般 / 大気水圏科学

担当教育組織

•  学士課程　理学部
•  修士課程　理学院
•  博士課程　理学院

職歴

• 2006年 - 現在 北海道大学 大学院・理学研究院 教授
• 2003年06月 - 2006年07月 文部科学省 研究振興局 学術調査官
• 2003年 - 2005年 北海道大学 理学(系)研究科(研究院) 助教授
• 2005年 北海道大学 大学院・理学研究科 教授
• 1998年04月 - 2004年03月 (独)海洋研究開発機構 地球フロンティア研究システム・国際北極研究センター 研究員
• 1998年 - 2004年 北海道大学 大学院・理学研究科 助教授
• 2004年 北海道大学 理学研究科 助教授
• 1998年 - 1999年 北海道大学 理学（系）研究科 助教授
• 1995年 - 1996年 北海道大学 大学院・理学研究科 助手
• 1996年 北海道大学 理学（系）研究科 助手
• 1994年06月 - 1994年09月 ワシントン大学客員研究員
• 1989年 北海道大学 理学部 助手

所属学協会

• 日本地球惑星科学連合   アメリカ気象学会   アメリカ地球物理学連合   日本気象学会   日本海洋学会   

研究活動情報

論文

• Toward Regional Marine Ecological Forecasting Using Global Climate Model Predictions From Subseasonal to Decadal Timescales: Bottlenecks and Recommendations

  Shoshiro Minobe, Antonietta Capotondi, Michael G. Jacox, Masami Nonaka, Ryan R. Rykaczewski

  FRONTIERS IN MARINE SCIENCE 9 2022年08月 

  This perspective paper discusses how the research community can promote enhancement of marine ecosystem forecasts using physical ocean conditions predicted by global climate models (GCMs). We review the major climate prediction projects and outline new research opportunities to achieve skillful marine biological forecasts. Physical ocean conditions are operationally predicted for subseasonal to seasonal timescales, and multi-year predictions have been enhanced recently. However, forecasting applications are currently limited by the availability of oceanic data; most subseasonal-to-seasonal prediction projects make only sea-surface temperature (SST) publicly available, though other variables useful for biological forecasts are also calculated in GCMs. To resolve the bottleneck of data availability, we recommend that climate prediction centers increase the range of ocean data available to the public, perhaps starting with an expanded suite of 2-dimensional variables, whose storage requirements are much smaller than 3-dimensional variables. Allowing forecast output to be downloaded for a selected region, rather than the whole globe, would also facilitate uptake. We highlight new research opportunities in both physical forecasting (e.g., new approaches to dynamical and statistical downscaling) and biological forecasting (e.g., conducting biological reforecasting experiments) and offer lessons learned to help guide their development. In order to accelerate this research area, we also suggest establishing case studies (i.e., particular climate and biological events as prediction targets) to improve coordination. Advancing our capacity for marine biological forecasting is crucial for the success of the UN Decade of Ocean Science, for which one of seven desired outcomes is "A Predicted Ocean".
• Sea surface temperature predictability in the North Pacific from multi-model seasonal forecast

  Emi Yati, Shoshiro Minobe

  JOURNAL OF OCEANOGRAPHY 2021年09月 [査読有り]
   

  Sea surface temperature (SST) prediction based on the multi-model seasonal forecast with numerous ensemble members have more useful skills to estimate the possibility of climate events than individual models. Hence, we assessed SST predictability in the North Pacific (NP) from multi-model seasonal forecasts. We used 23 years of hindcast data from three seasonal forecasting systems in the Copernicus Climate Change Service to estimate the prediction skill based on temporal correlation. We evaluated the predictability of the SST from the ensemble members' width spread, and co-variability between the ensemble mean and observation. Our analysis revealed that areas with low prediction skills were related to either the large spread of ensemble members or the ensemble members not capturing the observation within their spread. The large spread of ensemble members reflected the high forecast uncertainty, as exemplified in the Kuroshio-Oyashio Extension region in July. The ensemble members not capturing the observation indicates the model bias; thus, there is room for improvements in model prediction. On the other hand, the high prediction skills of the multi-model were related to the small spread of ensemble members that captures the observation, as in the central NP in January. Such high predictability is linked to El Nino Southern Oscillation (ENSO) via teleconnection.
• Marine Ecosystem Variations Over the North Pacific and Their Linkage to Large-Scale Climate Variability and Change

  Emi Yati, Shoshiro Minobe, Nathan Mantua, Shin-ichi Ito, Emanuele Di Lorenzo

  Frontiers in Marine Science 7 2020年11月05日 [査読有り]
  
• Influence of model resolution on bomb cyclones revealed by HighResMIP-PRIMAVERA simulations

  Gao Jiaxiang, Minobe Shoshiro, Malcolm J Roberts, Rein Haarsma, Dian Putrasahan, Christopher D Roberts, Enrico Scoccimarro, Laurent Terray, Benoît Vannière, Pier Luigi Vidale

  Environmental Research Letters 2020年07月24日 [査読有り]
  
• Relations between Interannual Variability of Regional-Scale Indonesian Precipitation and Large-Scale Climate Modes during 1960–2007

  Givo Alsepan, Shoshiro Minobe

  Journal of Climate 33 12 5271 - 5291 2020年06月15日 [査読有り]
  
• Diurnal Cycles of Precipitation and Lightning in the Tropics Observed by TRMM3G68, GSMaP, LIS, and WWLLN

  Shoshiro Minobe, Jun Hyock Park, Katrina S. Virts

  Journal of Climate 33 10 4293 - 4313 2020年05月15日 [査読有り]
  
• Insights from Earth system model initial-condition large ensembles and future prospects

  C. Deser, F. Lehner, K. B. Rodgers, T. Ault, T. L. Delworth, P. N. DiNezio, A. Fiore, C. Frankignoul, J. C. Fyfe, D. E. Horton, J. E. Kay, R. Knutti, N. S. Lovenduski, J. Marotzke, K. A. McKinnon, S. Minobe, J. Randerson, J. A. Screen, I. R. Simpson, M. Ting

  Nature Climate Change 10 4 277 - 286 2020年04月02日 [査読有り][通常論文]
  
• Mechanisms of Future Changes in Equatorial Upwelling: CMIP5 Intermodel Analysis

  Mio Terada, Shoshiro Minobe, Curtis Deutsch

  JOURNAL OF CLIMATE 33 2 497 - 510 2020年01月 

  The future change in equatorial upwelling between 1971-2000 and 2071-2100 is investigated using data from 24 coupled climate models. The multimodel ensemble (MME) mean exhibits substantial equatorial upwelling decrease in the eastern Pacific and weaker decrease in the western Atlantic Ocean. The MME mean of upwelling change and intermodel variation of that are decomposed into distinct isopycnal and diapycnal components. In the Pacific, the diapycnal upwelling decreases near the surface, associated with a weakened Ekman pumping. The isopycnal upwelling decreases at depths of 75-200 m around the core of the Equatorial Undercurrent (EUC) due to flattening of the density layer in which it flows. Both the weakened Ekman pumping and the EUC flattening are induced by the locally weakened trade wind over the eastern Pacific basin. In the equatorial Atlantic, both the change in MME mean and the intermodel variation of upwellings are significantly related to the weakened trade wind and enhanced stratification, although these drivers are not independent. The results for the Pacific Ocean imply that future reduction in upwelling may have impacts at different depths by different mechanisms. In particular, the rapid warming of sea surface temperature in the eastern Pacific basin may be mainly caused by the near-surface diapycnal upwelling reduction rather than isopycnal upwelling reduction associated EUC flattening, which is important at deeper levels.
• Simulating the Midlatitude Atmospheric Circulation: What Might We Gain From High-Resolution Modeling of Air-Sea Interactions?

  A. Czaja, C. Frankignoul, S. Minobe, B. Vannière

  Current Climate Change Reports 5 4 390 - 406 2019年12月 [査読有り][招待有り]
   

  To provide a snapshot of the current research on the oceanic forcing of the atmospheric circulation in midlatitudes and a concise update on previous review papers. Atmospheric models used for seasonal and longer timescales predictions are starting to resolve motions so far only studied in conjunction with weather forecasts. These phenomena have horizontal scales of ~ 10–100 km which coincide with energetic scales in the ocean circulation. Evidence has been presented that, as a result of this matching of scale, oceanic forcing of the atmosphere was enhanced in models with 10–100 km grid size, especially at upper tropospheric levels. The robustness of these results and their underlying mechanisms are however unclear. Despite indications that higher resolution atmospheric models respond more strongly to sea surface temperature anomalies, their responses are still generally weaker than those estimated empirically from observations. Coarse atmospheric models (grid size greater than 100 km) will miss important signals arising from future changes in ocean circulation unless new parameterizations are developed.
• Sea Level and the Role of Coastal Trapped Waves in Mediating the Influence of the Open Ocean on the Coast

  Chris W. Hughes, Ichiro Fukumori, Stephen M. Griffies, John M. Huthnance, Shoshiro Minobe, Paul Spence, Keith R. Thompson, Anthony Wise

  Surveys in Geophysics 40 6 1467 - 1492 2019年11月 [査読有り][招待有り]
  
• Uncertainties in Long-Term Twenty-First Century Process-Based Coastal Sea-Level Projections

  R. S. W. van de Wal, X. Zhang, S. Minobe, S. Jevrejeva, R. E. M. Riva, C. Little, K. Richter, M. D. Palmer

  Surveys in Geophysics 40 6 1655 - 1671 2019年11月 [査読有り][招待有り]
   

  Many processes affect sea level near the coast. In this paper, we discuss the major uncertainties in coastal sea-level projections from a process-based perspective, at different spatial and temporal scales, and provide an outlook on how these uncertainties may be reduced. Uncertainty in centennial global sea-level rise is dominated by the ice sheet contributions. Geographical variations in projected sea-level change arise mainly from dynamical patterns in the ocean response and other geophysical processes. Finally, the uncertainties in the short-duration extreme sea-level events are controlled by near coastal processes, storms and tides.
• Towards Comprehensive Observing and Modeling Systems for Monitoring and Predicting Regional to Coastal Sea Level

  Rui M. Ponte, Mark Carson, Mauro Cirano, Catia M. Domingues, Svetlana Jevrejeva, Marta Marcos, Gary Mitchum, R. S. W. van de Wal, Philip L. Woodworth, Michael Ablain, Fabrice Ardhuin, Valerie Ballu, Melanie Becker, Jerome Benveniste, Florence Birol, Elizabeth Bradshaw, Anny Cazenave, P. De Mey-Fremaux, Fabien Durand, Tal Ezer, Lee-Lueng Fu, Ichiro Fukumori, Kathy Gordon, Mederic Gravelle, Stephen M. Griffies, Weiqing Han, Angela Hibbert, Chris W. Hughes, Deborah Idier, Villy H. Kourafalou, Christopher M. Little, Andrew Matthews, Angelique Melet, Mark Merrifield, Benoit Meyssignac, Shoshiro Minobe, Thierry Penduff, Nicolas Picot, Christopher Piecuch, Richard D. Ray, Lesley Rickards, Alvaro Santamaria-Gomez, Detlef Stammer, Joanna Staneva, Laurent Testut, Keith Thompson, Philip Thompson, Stefano Vignudelli, Joanne Williams, Simon D. P. Williams, Guy Woppelmann, Laure Zanna, Xuebin Zhang

  FRONTIERS IN MARINE SCIENCE 6 2019年07月 [査読有り][通常論文]
   

  A major challenge for managing impacts and implementing effective mitigation measures and adaptation strategies for coastal zones affected by future sea level (SL) rise is our limited capacity to predict SL change at the coast on relevant spatial and temporal scales. Predicting coastal SL requires the ability to monitor and simulate a multitude of physical processes affecting SL, from local effects of wind waves and river runoff to remote influences of the large-scale ocean circulation on the coast. Here we assess our current understanding of the causes of coastal SL variability on monthly to multi-decadal timescales, including geodetic, oceanographic and atmospheric aspects of the problem, and review available observing systems informing on coastal SL. We also review the ability of existing models and data assimilation systems to estimate coastal SL variations and of atmosphere-ocean global coupled models and related regional downscaling efforts to project future SL changes. We discuss (1) observational gaps and uncertainties, and priorities for the development of an optimal and integrated coastal SL observing system, (2) strategies for advancing model capabilities in forecasting short-term processes and projecting long-term changes affecting coastal SL, and (3) possible future developments of sea level services enabling better connection of scientists and user communities and facilitating assessment and decision making for adaptation to future coastal SL change.
• Ocean Climate Observing Requirements in Support of Climate Research and Climate Information

  Detlef Stammer, Annalisa Bracco, Krishna AchutaRao, Lisa Beal, Nathaniel L. Bindoff, Pascale Braconnot, Wenju Cai, Dake Chen, Matthew Collins, Gokhan Danabasoglu, Boris Dewitte, Riccardo Farneti, Baylor Fox-Kemper, John Fyfe, Stephen M. Griffies, Steven R. Jayne, Alban Lazar, Matthieu Lengaigne, Xiaopei Lin, Simon Marsland, Shoshiro Minobe, Pedro M. S. Monteiro, Walter Robinson, Mathew Koll Roxy, Ryan R. Rykaczewski, Sabrina Speich, Inga J. Smith, Amy Solomon, Andrea Storto, Ken Takahashi, Thomas Toniazzo, Jerome Vialard

  FRONTIERS IN MARINE SCIENCE 6 2019年07月 [査読有り][通常論文]
   

  Natural variability and change of the Earth's climate have significant global societal impacts. With its large heat and carbon capacity and relatively slow dynamics, the ocean plays an integral role in climate, and provides an important source of predictability at seasonal and longer timescales. In addition, the ocean provides the slowly evolving lower boundary to the atmosphere, driving, and modifying atmospheric weather. Understanding and monitoring ocean climate variability and change, to constrain and initialize models as well as identify model biases for improved climate hindcasting and prediction, requires a scale-sensitive, and long-term observing system. A climate observing system has requirements that significantly differ from, and sometimes are orthogonal to, those of other applications. In general terms, they can be summarized by the simultaneous need for both large spatial and long temporal coverage, and by the accuracy and stability required for detecting the local climate signals. This paper reviews the requirements of a climate observing system in terms of space and time scales, and revisits the question of which parameters such a system should encompass to meet future strategic goals of the World Climate Research Program (WCRP), with emphasis on ocean and sea-ice covered areas. It considers global as well as regional aspects that should be accounted for in designing observing systems in individual basins. Furthermore, the paper discusses which data-driven products are required to meet WCRP research and modeling needs, and ways to obtain them through data synthesis and assimilation approaches. Finally, it addresses the need for scientific capacity building and international collaboration in support of the collection of high-quality measurements over the large spatial scales and long time-scales required for climate research, bridging the scientific rational to the required resources for implementation.
• Origin of intraseasonal variability in the eastern equatorial Indian Ocean: intrinsic variability and local and remote wind stress forcings

  Chorong Lee, Shoshiro Minobe, Yoshi N. Sasaki

  Journal of Oceanography 75 2 119 - 137 2019年04月 [査読有り][通常論文]
  
• Mechanisms of Low‐Frequency Oxygen Variability in the North Pacific

  Takamitsu Ito, Matthew C. Long, Curtis Deutsch, Shoshiro Minobe, Daoxun Sun

  Global Biogeochemical Cycles 33 2 110 - 124 2019年02月 [査読有り]
  
• The Benefits of Global High Resolution for Climate Simulation: Process Understanding and the Enabling of Stakeholder Decisions at the Regional Scale

  M. J. Roberts, P. L. Vidale, C. Senior, H. T. Hewitt, C. Bates, S. Berthou, P. Chang, H. M. Christensen, S. Danilov, M.-E. Demory, S. M. Griffies, R. Haarsma, T. Jung, G. Martin, S. Minobe, T. Ringler, M. Satoh, R. Schiemann, E. Scoccimarro, G. Stephens, M. F. Wehner

  Bulletin of the American Meteorological Society 99 11 2341 - 2359 2018年11月 [査読有り][招待有り]
   

  The time scales of the Paris Climate Agreement indicate urgent action is required on climate policies over the next few decades, in order to avoid the worst risks posed by climate change. On these relatively short time scales the combined effect of climate variability and change are both key drivers of extreme events, with decadal time scales also important for infrastructure planning. Hence, in order to assess climate risk on such time scales, we require climate models to be able to represent key aspects of both internally driven climate variability and the response to changing forcings. In this paper we argue that we now have the modeling capability to address these requirements—specifically with global models having horizontal resolutions considerably enhanced from those typically used in previous Intergovernmental Panel on Climate Change (IPCC) and Coupled Model Intercomparison Project (CMIP) exercises. The improved representation of weather and climate processes in such models underpins our enhanced confidence in predictions and projections, as well as providing improved forcing to regional models, which are better able to represent local-scale extremes (such as convective precipitation). We choose the global water cycle as an illustrative example because it is governed by a chain of processes for which there is growing evidence of the benefits of higher resolution. At the same time it comprises key processes involved in many of the expected future climate extremes (e.g., flooding, drought, tropical and midlatitude storms).
• Interannual to decadal variability of the upper-ocean heat content in the western North Pacific and its relationship to oceanic and atmospheric variability

  Hanna Na, Kwang-Yul Kim, Shoshiro Minobe, Yoshi N. Sasaki

  Journal of Climate 31 13 5107 - 5125 2018年07月01日 [査読有り][通常論文]
   

  Three-dimensional oceanic thermal structures and variability in the western North Pacific (NP) are examined on the interannual to decadal time scales and their relationship to oceanic and atmospheric variability is discussed by analyzing observation and reanalysis data for 45 years (1964-2008), which is much longer than the satellite-altimetry period. It is shown that the meridional shift of the Kuroshio Extension (KE) and subarctic frontal zone (SAFZ) is associated with the overall cooling/warming over the KE and SAFZ region (KE-SAFZ mode). It appears, however, that changes in KE strength induce different signs of thermal anomalies to the south and north of the KE, not extended to the SAFZ (KE mode), possibly contributing to noncoherent variability between the KE and SAFZ. Thus, the KE and SAFZ are dependent on each other in the context of the KE-SAFZ mode, while the KE is independent of the SAFZ in terms of the KE mode. This intricate relationship is associated with different linkages to atmospheric variability the KE-SAFZ mode exhibits a relatively fast response to the large-scale wind stress curl forcing in the NP, whereas the KE mode is related to a delayed response to the atmospheric forcing via jet-trapped baroclinic Rossby wave propagation. It is suggested that further knowledge of the underlying mechanisms of the two modes would contribute to understanding ocean-atmosphere feedback as well as potential predictability over the western boundary current region in the NP.
• Projected sea level rise, gyre circulation and water mass formation in the western North Pacific: CMIP5 inter-model analysis

  Mio Terada, Shoshiro Minobe

  Climate Dynamics 50 11-12 4767 - 4782 2018年06月01日 [査読有り][通常論文]
   

  Future changes in the dynamic sea level (DSL), which is defined as sea-level deviation from the global mean sea level, is investigated over the North Pacific, by analyzing data from the Coupled Model Intercomparison Project Phase 5. The analysis provides more comprehensive descriptions of DSL responses to the global warming in this region than available from previous studies, by using surface and subsurface data until the year 2300 under middle and high greenhouse-gas emission scenarios. The DSL changes in the North Pacific are characterized by a DSL rise in the western North Pacific around the Kuroshio Extension (KE), as also reported by previous studies. Subsurface density analysis indicates that DSL rise around the KE is associated with decrease in density of subtropical mode water (STMW) and with northward KE migration, the former (latter) of which is relatively strong between 2000 and 2100 for both RCP4.5 and RCP8.5 (between 2100 and 2300 for RCP8.5). The STMW density decrease is related to large heat uptake to the south and southeast of Japan, while the northward KE migration is associated with the poleward shift of the wind stress field. These features are commonly found in multi-model ensemble means and the relations among representative quantities produced by different climate models.
• Challenges and opportunities for improved understanding of regional climate dynamics

  Matthew Collins, Shoshiro Minobe, Marcelo Barreiro, Simona Bordoni, Yohai Kaspi, Akira Kuwano-Yoshida, Noel Keenlyside, Elisa Manzini, Christopher H. O'Reilly, Rowan Sutton, Shang-Ping Xie, Olga Zolina

  Nature Climate Change 8 2 101 - 108 2018年02月01日 [査読有り][通常論文]
   

  Dynamical processes in the atmosphere and ocean are central to determining the large-scale drivers of regional climate change, yet their predictive understanding is poor. Here, we identify three frontline challenges in climate dynamics where significant progress can be made to inform adaptation: response of storms, blocks and jet streams to external forcing basin-to-basin and tropical-extratropical teleconnections and the development of non-linear predictive theory. We highlight opportunities and techniques for making immediate progress in these areas, which critically involve the development of high-resolution coupled model simulations, partial coupling or pacemaker experiments, as well as the development and use of dynamical metrics and exploitation of hierarchies of models.
• Sea level variability around Japan during the twentieth century simulated by a regional ocean model

  Yoshi N. Sasaki, Ryosuke Washizu, Tamaki Yasuda, Shoshiro Minobe

  Journal of Climate 30 14 5585 - 5595 2017年07月01日 [査読有り][通常論文]
   

  Sea level variability around Japan from 1906 to 2010 is examined using a regional ocean model, along with observational data and the CMIP5 historical simulations. The regional model reproduces observed interdecadal sea level variability, for example, high sea level around 1950, low sea level in the 1970s, and sea level rise during the most recent three decades, along the Japanese coast. Sensitivity runs reveal that the high sea level around 1950 was induced by the wind stress curl changes over the North Pacific, characterized by a weakening of the Aleutian low. In contrast, the recent sea level rise is primarily caused by heat and freshwater flux forcings. That the wind-induced sea level rise along the Japanese coast around 1950 is as large as the recent sea level rise highlights the importance of natural variability in understanding regional sea level change on interdecadal time scales.
• Western Boundary Sea Level: A Theory, Rule of Thumb, and Application to Climate Models

  Shoshiro Minobe, Mio Terada, Bo Qiu, Niklas Schneider

  JOURNAL OF PHYSICAL OCEANOGRAPHY 47 5 957 - 977 2017年05月 [査読有り][通常論文]
   

  To better understand coastal sea level variability and changes, a theory that predicts sea levels along a curved western boundary using interior ocean sea level information is proposed. The western boundary sea level at a particular latitude is expressed by the sum of contributions from interior sea levels propagating onto the western boundary by long Rossby waves between that latitude and a higher latitude, and from the western boundary sea level at the higher latitude. This theory is examined by using a linear, reduced gravity model. A comparison between the theory and the model shows good agreement. A simple scaling law (or rule of thumb) derived from the theory provides a measure of the higher-latitude sea level and ocean interior sea level contributions. The theory is then tested using data from 34 climate models in phase 5 of the Coupled Model Intercomparison Project (CMIP5) for dynamic sea level changes between the end of the twentieth and twenty-first centuries. The theory captures the nearly uniform sea level rise from the Labrador Sea to New York City (NYC), with a reduction in the increase of sea level farther south toward the equator, qualitatively consistent with the CMIP5 multimodel ensemble, even though the theory underestimates the equatorward reduction rate. Along the South American east coast, the theory successfully reproduced the spatial pattern of the sea level change. The theory suggests a strong link between a sea level rise hot spot along the northeastern coast of North America and the sea level increase in the Labrador Sea, consistent with the result that rates of NYC sea level rise are highly correlated to those in the Labrador Sea in CMIP5 models.
• Upper ocean O-2 trends: 1958-2015

  Takamitsu Ito, Shoshiro Minobe, Matthew C. Long, Curtis Deutsch

  GEOPHYSICAL RESEARCH LETTERS 44 9 4214 - 4223 2017年05月 [査読有り][通常論文]
   

  Historic observations of dissolved oxygen (O-2) in the ocean are analyzed to quantify multidecadal trends and variability from 1958 to 2015. Additional quality control is applied, and the resultant oxygen anomaly field is used to quantify upper ocean O-2 trends at global and hemispheric scales. A widespread negative O-2 trend is beginning to emerge from the envelope of interannual variability. Ocean reanalysis data are used to evaluate relationships with changes in ocean heat content (OHC) and oxygen solubility (O-2,O-sat). Global O-2 decline is evident after the 1980s, accompanied by an increase in global OHC. The global upper ocean O-2 inventory (0-1000m) changed at the rate of -243124TmolO(2) per decade. Further, the O-2 inventory is negatively correlated with the OHC (r=-0.86; 0-1000m) and the regression coefficient of O-2 to OHC is approximately -8.20.66nmolO(2)J(-1), on the same order of magnitude as the simulated O-2-heat relationship typically found in ocean climate models. Variability and trends in the observed upper ocean O-2 concentration are dominated by the apparent oxygen utilization component with relatively small contributions from O-2,O-sat. This indicates that changing ocean circulation, mixing, and/or biochemical processes, rather than the direct thermally induced solubility effects, are the primary drivers for the observed O-2 changes. The spatial patterns of the multidecadal trend include regions of enhanced ocean deoxygenation including the subpolar North Pacific, eastern boundary upwelling systems, and tropical oxygen minimum zones. Further studies are warranted to understand and attribute the global O-2 trends and their regional expressions. Plain Language Summary This new paper describes the analysis of the dissolved oxygen in the global ocean using the most recent version of the World Ocean Database for the period of 1955 to 2015. After careful examination of the data, we found that a statistically significant, widespread O-2 decline is emerging beyond the envelope of natural fluctuations. Our study also reveals a tight relationship between O-2 inventories and the ocean heat content. The spatial pattern and magnitude of this relationship are consistent with expectations derived from mechanistic ocean climate models forced under climate warming scenarios. Taken together, the trends we document here are suggestive of the effects of the ocean warming beginning to supersede natural variability and emerge as a recognizable signal. This merits additional scrutiny over the coming years.
• Storm-Track Response to SST Fronts in the Northwestern Pacific Region in an AGCM

  Akira Kuwano-Yoshida, Shoshiro Minobe

  JOURNAL OF CLIMATE 30 3 1081 - 1102 2017年02月 [査読有り][通常論文]
   

  The storm-track response to sea surface temperature (SST) fronts in the northwestern Pacific region is investigated using an atmospheric general circulation model with a 50-km horizontal resolution. The following two experiments are conducted: one with 0.25 degrees daily SST data (CNTL) and the other with smoothed SSTs over an area covering SST fronts associated with the Kuroshio, the Kuroshio Extension, the Oyashio, and the subpolar front (SMTHK). The storm track estimated from the local deepening rate of surface pressure (LDR) exhibits a prominent peak in this region in CNTL in January, whereas the storm-track peak weakens and moves eastward in SMTHK. Storm-track differences between CNTL and SMTHK are only found in explosive deepening events with LDR larger than 1 hPa h(-1). A diagnostic equation of LDR suggests that latent heat release associated with large-scale condensation contributes to the storm-track enhancement. The SST fronts also affect the large-scale atmospheric circulation over the northeastern Pacific Ocean. The jet stream in the upper troposphere tends to meander northward, which is associated with positive sea level pressure (SLP) anomalies in CNTL, whereas the jet stream flows zonally in SMTHK. A composite analysis for the northwestern Pacific SLP anomaly suggests that frequent explosive cyclone development in the northwestern Pacific in CNTL causes downstream positive SLP anomalies over the Gulf of Alaska. Cyclones in SMTHK developing over the northeastern Pacific enhance the moisture flux along the west coast of North America, increasing precipitation in that region.
• The Gulf Stream influence on wintertime North Atlantic jet variability

  Christopher H. O'Reilly, Shoshiro Minobe, Akira Kuwano-Yoshida, Tim Woollings

  QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY 143 702 173 - 183 2017年01月 [査読有り][通常論文]
   

  In this article we investigate the influence of the Gulf Stream sea-surface temperature (SST) front on the North Atlantic eddy-driven jet and its variability, by analysing the NCEP-CFSR dataset and a pair of AGCM simulations forced with realistic and smoothed Gulf Stream SST boundary conditions. The Gulf Stream SST front acts to generate stronger meridional eddy heat flux in the lower troposphere and an eddy-driven jet over the eastern North Atlantic which is located further polewards than in the simulation with smoothed SST. The strong Gulf Stream SST gradient is found to be crucial in more accurately capturing the trimodal distribution of the eddy-driven jet latitude, with the more poleward climatological jet being the result of the jet occupying the northern jet position more frequently in the simulation forced with observed SSTs. The more frequent occurrence of the northern jet location is associated with periods of high eddy heat flux over the Gulf Stream region. Composite analysis of high eddy heat flux events reveals that the significantly higher heat flux is followed by larger and more persistient poleward jet excursions in the simulations with realistic SSTs than in the simulation with smoothed SSTs, with upper-tropospheric eddy momentum fluxes acting to maintain the more poleward eddy-driven jet. Periods of high eddy heat flux over the Gulf Stream region are also shown to be associated with increased blocking frequency over Europe, which are clearly distinct from periods with a northern jet position.
• Dynamical downscaling of future sea level change in the western North Pacific using ROMS

  Zhao-Jun Liu, Shoshiro Minobe, Yoshi N. Sasaki, Mio Terada

  JOURNAL OF OCEANOGRAPHY 72 6 905 - 922 2016年12月 [査読有り][通常論文]
   

  The future regional sea level (RSL) rise in the western North Pacific is investigated by dynamical downscaling with the Regional Ocean Modeling System (ROMS) with an eddy-permitting resolution based on three global climate models-MIROC-ESM, CSIRO-Mk3.6.0, and GFDL-CM3-under the highest greenhouse-gas emission scenario. The historical run is forced by the air-sea fluxes calculated from Coordinated Ocean Reference Experiment version 2 (COREv2) data. Three future runs-ROMS-MIROC, ROMS-CSIRO, and ROMS-GFDL-are forced with an atmospheric field constructed by adding the difference between the climate model parameters for the twenty-first and twentieth century to fields in the historical run. In all downscaling, the RSL rise along the eastern coast of Japan is generally half or less of the RSL rise maxima off the eastern coast. The projected regional (total) sea level rises along the Honshu coast during 2081-2100 relative to 1981-2000 are 19-25 (98-104), 6-15 (71-80), and 8-14 (80-86) cm in ROMS-MIROC, ROMS-CSIRO, and ROMS-GFDL, respectively. The discrepancies of the RSL rise along the Honshu coast between the climate models and downscaling are less than 10 cm. The RSL changes in the Kuroshio Extension (KE) region in all downscaling simulations are related to the changes of KE (northward shift or intensification) with climate change.
• The influence of the Gulf Stream on wintertime European blocking

  Christopher H. O'Reilly, Shoshiro Minobe, Akira Kuwano-Yoshida

  CLIMATE DYNAMICS 47 5-6 1545 - 1567 2016年09月 [査読有り][通常論文]
   

  Wintertime blocking is responsible for extended periods of anomalously cold and dry weather over Europe. In this study, the influence of the Gulf Stream sea surface temperature (SST) front on wintertime European blocking is investigated using a reanalysis dataset and a pair of atmospheric general circulation model (AGCM) simulations. The AGCM is forced with realistic and smoothed Gulf Stream SST, and blocking frequency over Europe is found to depend crucially on the Gulf Stream SST front. In the absence of the sharp SST gradient European blocking is significantly reduced and occurs further downstream. The Gulf Stream is found to significantly influence the surface temperature anomalies during blocking periods and the occurrence of associated cold spells. In particular the cold spell peak, located in central Europe, disappears in the absence of the Gulf Stream SST front. The nature of the Gulf Stream influence on European blocking development is then investigated using composite analysis. The presence of the Gulf Stream SST front is important in capturing the observed quasi-stationary development of European blocking. The development is characterised by increased lower-tropospheric meridional eddy heat transport in the Gulf Stream region and increased eddy kinetic energy at upper-levels, which acts to reinforce the quasi-stationary jet. When the Gulf Stream SST is smoothed the storm track activity is weaker, the development is less consistent and European blocking occurs less frequently.
• An east-west contrast of upper ocean heat content variation south of the subpolar front in the East/Japan Sea

  Seung-Tae Yoon, Kyung-Il Chang, Hanna Na, Shoshiro Minobe

  JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS 121 8 6418 - 6443 2016年08月 [査読有り][通常論文]
   

  Long-term variability of nonseasonal ocean heat content (OHC) in the upper 500 m in the East/ Japan Sea (EJS) exhibits a distinct east-west contrast during the recent 30 years. The contrasting OHC variations are revisited and investigated more in detail by analyzing two observational data sets, the gridded data from 1976 to 2007 and in situ data from 1976 to 2011 in the southwestern EJS that covers the zone of western boundary current. The OHC variability shows in-phase and predominant decadal variation in both east and west regions before 1995, but uncorrelated and predominant interannual variations after 1995. Heaving effects due to major branches of warm currents in the EJS, the East Korea Warm Current (EKWC) in the western part and other two branches in the eastern part, mainly contribute to the OHC variations. The heaving effect in the western EJS is shown to be associated with changes in winter wind-stress curl field in the northern EJS. Weakening of the subpolar gyre due to weakening of positive wind-stress curl in the Japan Basin related with wintertime Western Pacific teleconnection pattern and Siberian High appears to enhance the northward penetration of the EKWC resulting in an increase of OHC in the western EJS. The heaving effect in the eastern EJS is significantly correlated with the Siberian High, but the causative mechanism is inconclusive. This study also demonstrates the importance of using highly resolved data sets for areas affected by strong and narrow boundary currents in computing and understanding the OHC variability.
• CLIVAR/JAMSTEC Workshop on the Kuroshio Current and Extension System: Theory, Observations, and Ocean Climate Modelling-The Workshop Overview and Outcomes

  Yoshiki Komuro, Gokhan Danabasoglu, Simon Marsland, Xiaopei Lin, Shoshiro Minobe, Anna Pirani, Tatsuo Suzuki, Ichiro Yasuda

  CLIVAR Exchanges 69 1 - 6 2016年07月 [査読無し][通常論文]
  
• The Pacific Decadal Oscillation, Revisited

  Matthew Newman, Michael A. Alexander, Toby R. Ault, Kim M. Cobb, Clara Deser, Emanuele Di Lorenzo, Nathan J. Mantua, Arthur J. Miller, Shoshiro Minobe, Hisashi Nakamura, Niklas Schneider, Daniel J. Vimont, Adam S. Phillips, James D. Scott, Catherine A. Smith

  JOURNAL OF CLIMATE 29 12 4399 - 4427 2016年06月 [査読有り][通常論文]
   

  The Pacific decadal oscillation (PDO), the dominant year-round pattern of monthly North Pacific sea surface temperature (SST) variability, is an important target of ongoing research within the meteorological and climate dynamics communities and is central to the work of many geologists, ecologists, natural resource managers, and social scientists. Research over the last 15 years has led to an emerging consensus: the PDO is not a single phenomenon, but is instead the result of a combination of different physical processes, including both remote tropical forcing and local North Pacific atmosphere-ocean interactions, which operate on different time scales to drive similar PDO-like SST anomaly patterns. How these processes combine to generate the observed PDO evolution, including apparent regime shifts, is shown using simple autoregressive models of increasing spatial complexity. Simulations of recent climate in coupled GCMs are able to capture many aspects of the PDO, but do so based on a balance of processes often more independent of the tropics than is observed. Finally, it is suggested that the assessment of PDO-related regional climate impacts, reconstruction of PDO-related variability into the past with proxy records, and diagnosis of Pacific variability within coupled GCMs should all account for the effects of these different processes, which only partly represent the direct forcing of the atmosphere by North Pacific Ocean SSTs.
• The atmospheric frontal response to SST perturbations in the Gulf Stream region

  Rhys Parfitt, Arnaud Czaja, Shoshiro Minobe, Akira Kuwano-Yoshida

  GEOPHYSICAL RESEARCH LETTERS 43 5 2299 - 2306 2016年03月 [査読有り][通常論文]
   

  The link between sea surface temperature (SST) gradients and atmospheric fronts is explored in a general circulation model across the Gulf Stream (GS) region from December to February 1981-2000. Two model experiments are analyzed, one with a realistic control SST distribution and one with a spatially smoothed SST distribution. The analysis shows a noticeable change in regional atmospheric frontal frequency between the two experiments (up to 30%), with the distribution of change exhibiting a clear imprint of the GS SST front. Further analysis of the surface sensible heat flux gradient across cold fronts reveals the pattern of change to be mediated by a thermal interaction between the oceanic and atmospheric fronts (thermal damping and strengthening). These results not only emphasize the significance of the GS SST gradient for storm development in the North Atlantic but also highlight the importance of resolution in assessing the role of frontal air-sea interaction in midlatitude climate variability.
• Influence of the Kuroshio on Mesoscale Convective Systems in the Baiu Frontal Zone over the East China Sea

  Kazutoshi Sato, Atsuyoshi Manda, Qoosaku Moteki, Kensuke K. Komatsu, Koto Ogata, Hatsumi Nishikawa, Miki Oshika, Yuriko Otomi, Shiori Kunoki, Hisao Kanehara, Takashi Aoshima, Kenichi Shimizu, Jun Uchida, Masako Shimoda, Mitsuharu Yagi, Shoshiro Minobe, Yoshihiro Tachibana

  MONTHLY WEATHER REVIEW 144 3 1017 - 1033 2016年03月 [査読有り][通常論文]
   

  Two mesoscale convective events in the baiu frontal zone (BFZ) were documented, based on intensive atmospheric soundings and oceanic castings in the East China Sea during May 2011, in addition to continuous surface meteorological observations, satellite products, and objective analyses. These events occurred while the BFZ was nearly stagnant and a mesolow was deepening in the zone. Near-surface southerlies associated with the low-level jet transported a warm, humid air mass from south of the BFZ. Enhanced evaporation, which was mainly attributable to the high sea surface temperature of the Kuroshio, augmented the moisture content of the air mass and helped maintain a convectively unstable stratification in the lower troposphere around the BFZ.
• Climatological mean features and interannual to decadal variability of ring formations in the Kuroshio extension region

  Yoshi N. Sasaki, Shoshiro Minobe

  Hot Spots in the Climate System: New Developments in the Extratropical Ocean-Atmosphere Interaction Research 31 - 41 2016年01月01日 [査読有り][通常論文]
   

  This study examines the climatological mean features of oceanic rings shed from the Kuroshio Extension (KE) jet and their interannual to decadal variability using satellite altimeter observations from October 1992 to December 2010. To objectively capture ring shedding from the KE jet, a new method that consists of the detection of the jet length changes and the tracking of a ring is proposed. Spatial distribution of the ring formations in the KE region indicates that cyclonic (cold-core) rings were most frequently formed in the upstream region between 143° and 147°E around the steady meander of the KE jet. In contrast, most of anticyclonic (warm-core) rings were formed in the downstream region west of the Shatsky Rise. These pinched-off rings in both the upstream and downstream regions generally propagated westward, but about two-thirds of the rings were reabsorbed by the jet. Nevertheless, about one-fourth of the meridional eddy heat transport at the latitude of the KE resulted from the rings that are not reabsorbed by the jet. The number of ring formations showed substantial interannual to decadal variability. In the upstream and downstream KE region, decadal and interannual variability was dominant, respectively. These ring formation fluctuations were negatively correlated with the strength of the KE jet. It is also revealed that the ring formation variations play an important role in sea surface temperature changes north of the KE jet.
• Air-sea interaction over the western boundary currents in the western north pacific

  Shoshiro Minobe, Bo Qiu, Masami Nonaka, Hisashi Nakamura

  World Scientific Series on Asia-Pacific Weather and Climate 7 187 - 211 2016年 [査読有り][通常論文]
   

  Studies of the ocean-To-Atmosphere feedback in the midlatitudes have developed rapidly in the last decade, especially in association with the western boundary currents (WBCs). In this article, an overview of the nature and variability of the WBCs in the North Pacific, i.e. The Kuroshio, the Kuroshio Extension (KE), the Subarctic (Oyashio) Front, and the Oyashio, is provided. The KE and the Subarctic Front, just apart by 5° in latitude, have different features for their mean structure, the physical mechanisms of temporal variability, and feedbacks to the atmosphere. The KE has a stronger heat release to the atmosphere than the Subarctic Front, mainly due to latent heat fluxes, but the Subarctic Front, accompanied by strong SST gradients, provides a stronger sensible heat gradient to the atmosphere. The atmospheric responses to these fronts may be viewed via two categories the local response and the remote response. Studies of the local response are substantially stimulated by the QuikSCAT satellite with the scale separation strategy. One of the key processes of the remote response is modulations of storm tracks associated with the oceanic fronts. Although large progress has been made in the last decade in understanding the mechanisms of variability of these WBCs and their feedback to the atmosphere, there are substantial uncertainties and questions to be explored.
• Climatological mean features and interannual to decadal variability of ring formations in the Kuroshio Extension region

  Yoshi N. Sasaki, Shoshiro Minobe

  JOURNAL OF OCEANOGRAPHY 71 5 499 - 509 2015年10月 [査読有り][通常論文]
   

  This study examines the climatological mean features of oceanic rings shed from the Kuroshio Extension (KE) jet and their interannual to decadal variability using satellite altimeter observations from October 1992 to December 2010. To objectively capture ring shedding from the KE jet, a new method that consists of the detection of the jet length changes and the tracking of a ring is proposed. Spatial distribution of the ring formations in the KE region indicates that cyclonic (cold-core) rings were most frequently formed in the upstream region between 143A degrees and 147A degrees E around the steady meander of the KE jet. In contrast, most of anticyclonic (warm-core) rings were formed in the downstream region west of the Shatsky Rise. These pinched-off rings in both the upstream and downstream regions generally propagated westward, but about two-thirds of the rings were reabsorbed by the jet. Nevertheless, about one-fourth of the meridional eddy heat transport at the latitude of the KE resulted from the rings that are not reabsorbed by the jet. The number of ring formations showed substantial interannual to decadal variability. In the upstream and downstream KE region, decadal and interannual variability was dominant, respectively. These ring formation fluctuations were negatively correlated with the strength of the KE jet. It is also revealed that the ring formation variations play an important role in sea surface temperature changes north of the KE jet.
• "Hot Spots" in the climate system-new developments in the extratropical ocean-atmosphere interaction research: a short review and an introduction

  Hisashi Nakamura, Atsuhiko Isobe, Shoshiro Minobe, Humio Mitsudera, Masami Nonaka, Toshio Suga

  JOURNAL OF OCEANOGRAPHY 71 5 463 - 467 2015年10月 [査読有り][通常論文]
  
• Diurnal precipitation and high cloud frequency variability over the Gulf Stream and over the Kuroshio

  Shoshiro Minobe, Shogo Takebayashi

  CLIMATE DYNAMICS 44 7-8 2079 - 2095 2015年04月 [査読有り][通常論文]
   

  Recent studies show mid-latitude western boundary currents (WBCs) substantially influence the atmosphere aloft, and an important feature is enhanced rain band over the WBCs in climatological mean field. However, how such long-term, climate phenomena are related to shorter, weather timescale phenomena are generally remained to be explored. In this paper, diurnal precipitation and cloud variations are investigated global mid-latitude oceans with emphasis on air-sea interactions over WBCs using satellite-derived precipitation and outgoing longwave radiation (OLR) datasets. Strong 24-h period components of precipitations are found over the Gulf Stream in summer and over the Kuroshio in the East China Sea in early summer (Baiu-Meiyu season), respectively. Similar diurnal precipitations are not observed in WBCs in the Southern Hemisphere year around. The diurnal precipitation cycles over the Gulf Stream and the Kuroshio exhibit peak phases in the early to late morning for the Gulf Stream and late morning to early afternoon for the Kuroshio, with southeastward phase propagations. High cloud frequency derived from OLR data exhibit consistent diurnal cycles. A substantial difference of diurnal cycles between the Gulf Stream and the Kuroshio regions are associated with the large-scale Baiu-Meiyu rain and cloud bands for the latter region. Diurnal precipitation and high cloud variability is found in the vicinity of the Kuroshio itself, embedded in the Baiu-Meiyu rain and cloud bands distributing in a wider area without a strong diurnal component. The spatial and seasonal distributions of the diurnal variability over these WBCs strongly suggests that the diurnal precipitation and cloud cycles are essential aspects of deep heating mode of atmospheric response recently reported for these WBCs. These results indicate that these WBCs in the Northern Hemisphere play an important role in modulating short-term precipitation variations, and on the other hand diurnal variability can be a substantial agent for the mid-latitude air-sea interaction.
• Oceanic influence on the Baiu frontal zone in the East China Sea

  Shiori Kunoki, Atsuyoshi Manda, Yasu-Masa Kodama, Satoshi Iizuka, Kazutoshi Sato, Ibnu Fathrio, Taku Mitsui, Hiromu Seko, Qoosaku Moteki, Shoshiro Minobe, Yoshihiro Tachibana

  Journal of Geophysical Research 120 2 449 - 463 2015年01月27日 [査読有り][通常論文]
   

  A high-resolution transect of atmospheric soundings across the Kuroshio Current in the East China Sea was conducted onboard a ship in June 2012 with the objective of analyzing the influence of the complex sea surface temperature (SST) distribution on the Baiu frontal zone (BFZ). Expendable bathythermograph castings and continuous surface meteorological observations were also examined. Two distinct mesoscale atmospheric fronts, characterized by changes of wind direction in the lower troposphere and surface air temperature, were found in the BFZ. One (northern) atmospheric front was observed around the SST front in relation to a warm water tongue extending from the Kuroshio. A high SST region around the northern atmospheric front enhances unstable near surface stratification and intensifies turbulent heat flux. They help modify the marine atmospheric boundary layer in the BFZ. The other (southern) atmospheric front was at the southern end of the BFZ. Intense evaporation over the Kuroshio and moisture transport by southerly winds were important in forming the conditionally unstable air masses in the lower troposphere of the BFZ.
• Oceanic influence on the Baiu frontal zone in the East China Sea

  Shiori Kunoki, Atsuyoshi Manda, Yasu-Masa Kodama, Satoshi Iizuka, Kazutoshi Sato, Ibnu Fathrio, Taku Mitsui, Hiromu Seko, Qoosaku Moteki, Shoshiro Minobe, Yoshihiro Tachibana

  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 120 2 449 - 463 2015年01月 [査読有り][通常論文]
   

  A high-resolution transect of atmospheric soundings across the Kuroshio Current in the East China Sea was conducted onboard a ship in June 2012 with the objective of analyzing the influence of the complex sea surface temperature (SST) distribution on the Baiu frontal zone (BFZ). Expendable bathythermograph castings and continuous surface meteorological observations were also examined. Two distinct mesoscale atmospheric fronts, characterized by changes of wind direction in the lower troposphere and surface air temperature, were found in the BFZ. One (northern) atmospheric front was observed around the SST front in relation to a warm water tongue extending from the Kuroshio. A high SST region around the northern atmospheric front enhances unstable near surface stratification and intensifies turbulent heat flux. They help modify the marine atmospheric boundary layer in the BFZ. The other (southern) atmospheric front was at the southern end of the BFZ. Intense evaporation over the Kuroshio and moisture transport by southerly winds were important in forming the conditionally unstable air masses in the lower troposphere of the BFZ.
• Diagnostics for Near-Surface Wind Response to the Gulf Stream in a Regional Atmospheric Model

  Kohei Takatama, Shoshiro Minobe, Masaru Inatsu, R. Justin Small

  JOURNAL OF CLIMATE 28 1 238 - 255 2015年01月 [査読有り][通常論文]
   

  The mechanisms acting on near-surface winds over the Gulf Stream are diagnosed using 5-yr outputs of a regional atmospheric model. The diagnostics for the surface-layer momentum vector, its curl, and its convergence are developed with a clear separation of pressure adjustment from downward momentum inputs from aloft in the surface-layer system. The results suggest that the downward momentum mixing mechanism plays a dominant role in contributing to the annual-mean climatological momentum curl, whereas the pressure adjustment mechanism plays a minor role. In contrast, the wind convergence is mainly due to the pressure adjustment mechanism. This can be explained by the orientation of background wind to the sea surface temperature front. The diagnostics also explain the relatively strong seasonal variation in surface-layer momentum convergence and the small seasonal variation in curl. Finally, the surface-layer response to other western boundary currents is examined using a reanalysis dataset.
• Transient and local weakening of surface winds observed above the Kuroshio front in the winter East China Sea

  Kenki Kasamo, Atsuhiko Isobe, Shoshiro Minobe, Atsuyoshi Manda, Hirohiko Nakamura, Koto Ogata, Hatsumi Nishikawa, Yoshihiro Tachibana, Shin'ichiro Kako

  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 119 3 1277 - 1291 2014年02月 [査読有り][通常論文]
   

  To confirm whether surface winds strengthen above warm waters around oceanic fronts using in situ data, a field measurement was conducted using both expendable bathythermographs and Global Positioning System sondes released concurrently across the Kuroshio front in the East China Sea in December 2010. In contrast to previous studies mainly based on satellite observations, the finding of the present field survey is the local weakening of surface winds at the northern flank of the Kuroshio front. From the above field observation in conjunction with a regional numerical model experiment, it is suggested that the northwesterly winds crossing the Kuroshio front from the cooler side first weaken at the northern flank of the front because of the onset of upward transfer of the nonslip condition at the sea surface. Thereafter, as the atmospheric mixed layer with warm and humid air mass develops gradually downwind over the Kuroshio region, the surface winds are gradually accelerated by the momentum mixing with strong winds aloft. The surface winds remain strong over the cool East China Sea shelf, and it is thus considered that the surface winds only weaken at the northern flank of the Kuroshio front. However, numerical modeling indicates that this local weakening of the surface winds occurs as a transient state with a short duration and such a structure has thus rarely been detected in the long-term averaged wind fields observed by satellites.
• Transient and local weakening of surface winds observed above the Kuroshio front in the winter East China Sea

  Kenki Kasamo, Atsuhiko Isobe, Shoshiro Minobe, Atsuyoshi Manda, Hirohiko Nakamura, Koto Ogata, Hatsumi Nishikawa, Yoshihiro Tachibana, Yoshihiro Tachibana, Shin’Ichiro Kako

  Journal of Geophysical Research 119 3 1277 - 1291 2014年02月 [査読有り][通常論文]
   

  © 2014. American Geophysical Union. All Rights Reserved. To confirm whether surface winds strengthen above warm waters around oceanic fronts using in situ data, a field measurement was conducted using both expendable bathythermographs and Global Positioning System sondes released concurrently across the Kuroshio front in the East China Sea in December 2010. In contrast to previous studies mainly based on satellite observations, the finding of the present field survey is the local weakening of surface winds at the northern flank of the Kuroshio front. From the above field observation in conjunction with a regional numerical model experiment, it is suggested that the northwesterly winds crossing the Kuroshio front from the cooler side first weaken at the northern flank of the front because of the onset of upward transfer of the “nonslip” condition at the sea surface. Thereafter, as the atmospheric mixed layer with warm and humid air mass develops gradually downwind over the Kuroshio region, the surface winds are gradually accelerated by the momentum mixing with strong winds aloft. The surface winds remain strong over the cool East China Sea shelf, and it is thus considered that the surface winds only weaken at the northern flank of the Kuroshio front. However, numerical modeling indicates that this local weakening of the surface winds occurs as a transient state with a short duration and such a structure has thus rarely been detected in the long-term averaged wind fields observed by satellites.
• Decadal sea-level variability along the coast of Japan in response to ocean circulation changes

  Yoshi N. Sasaki, Shoshiro Minobe, Yuji Miura

  JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS 119 1 266 - 275 2014年01月 [査読有り][通常論文]
   

  Decadal sea-level variability along the coast of Japan and its relation to large-scale ocean circulation changes from 1993 to 2010 was investigated using tide-gauge and satellite-derived sea-level data. A singular value decomposition (SVD) analysis is performed between coastal sea levels of Japan and sea levels in the western North Pacific. The first SVD mode reveals that the northward shifts of the Kuroshio Extension (KE) jet and the Kuroshio southeast of Japan accompany the coastal sea-level rise in the early 2000s and 2010, and their southward shifts accompany the coastal sea-level fall in the late 1990s and the late 2000s. The shifts of the KE jet are induced by westward propagating Rossby wave from the eastern North Pacific, which is concentrated along the KE jet axis as jet-trapped Rossby waves. The resulting sea-level changes along the coast of Japan show a strong spatial contrast. The sea-level fluctuation is quite large along the southeastern coast of Japan that is under the direct influence of the jet-trapped Rossby waves, and also large in the western coast of Japan, probably due to coastal waves that are excited by the incoming Rossby waves, but is small north of the KE jet latitude. Hence, the nature of the wave trapped by the KE jet produces an active zone and a shadow zone of coastal sea-level variability of Japan. Our results indicate that the correct representation of western boundary currents is necessary for reliable prediction of future coastal sea-level changes. Key Points <list list-type="bulleted"> Decadal sea level change of the coast of Japan shows strong spatial contrast The nature of the Kuroshio Extension jet produces the strong spatial contrast Understanding of western boundary currents is necessary for sea level prediction
• Decadal sea-level variability along the coast of Japan in response to ocean circulation changes

  Yoshi N. Sasaki, Shoshiro Minobe, Yuji Miura

  Journal of Geophysical Research: Oceans 119 1 266 - 275 2014年 [査読有り][通常論文]
   

  Decadal sea-level variability along the coast of Japan and its relation to large-scale ocean circulation changes from 1993 to 2010 was investigated using tide-gauge and satellite-derived sea-level data. A singular value decomposition (SVD) analysis is performed between coastal sea levels of Japan and sea levels in the western North Pacific. The first SVD mode reveals that the northward shifts of the Kuroshio Extension (KE) jet and the Kuroshio southeast of Japan accompany the coastal sea-level rise in the early 2000s and 2010, and their southward shifts accompany the coastal sea-level fall in the late 1990s and the late 2000s. The shifts of the KE jet are induced by westward propagating Rossby wave from the eastern North Pacific, which is concentrated along the KE jet axis as jettrapped Rossby waves. The resulting sea-level changes along the coast of Japan show a strong spatial contrast. The sea-level fluctuation is quite large along the southeastern coast of Japan that is under the direct influence of the jet-trapped Rossby waves, and also large in the western coast of Japan, probably due to coastal waves that are excited by the incoming Rossby waves, but is small north of the KE jet latitude. Hence, the nature of the wave trapped by the KE jet produces an "active zone" and a "shadow zone" of coastal sea-level variability of Japan. Our results indicate that the correct representation of western boundary currents is necessary for reliable prediction of future coastal sea-level changes. © 2013. American Geophysical Union. All Rights Reserved.
• Southward eddy heat transport occurring along southern flanks of the Kuroshio Extension and the Gulf Stream in a 1/10° global Ocean General Circulation Model.

  Kunihiro Aoki, Shoshiro Minobe, Youichi Tanimoto, Yoshikazu Sasai

  JOURNAL OF PHYSICAL OCEANOGRAPHY 43 9 1899 - 1910 2013年09月 [査読有り][通常論文]
   

  The present study investigates meridional heat transport induced by oceanic mesoscale variability in the World Ocean using a degrees global ocean general circulation model (OGCM) running on the Earth Simulator. The results indicate prominent poleward eddy heat transport around the western boundary currents and the Antarctic Circumpolar Current, and equatorward eddy heat transport in the equatorial region, consistent with the previous studies using coarse-resolution OGCMs. Such poleward eddy heat transport in midlatitude oceans suggests that the eddies act to reduce meridional background temperature gradients across the currents, as would be expected based on baroclinic instability. Interestingly, however, along the southern flanks of the eastward jets of the Kuroshio Extension and the Gulf Stream, southward eddy heat transport occurs in subsurface layers. This is likely due to the southward migration of warm water cores originating from southern areas adjacent to these currents. Southward movement of these cores is caused by interactions with unsteady meanders and cold eddies detaching from the meanders. The potential impact on biological production in the subtropical surface layers of these southward-traveling warm water cores is also discussed.
• Decadal Response of the Kuroshio Extension Jet to Rossby Waves: Observation and Thin-Jet Theory

  Yoshi N. Sasaki, Shoshiro Minobe, Niklas Schneider

  JOURNAL OF PHYSICAL OCEANOGRAPHY 43 2 442 - 456 2013年02月 [査読有り][通常論文]
   

  This study examines interannual to decadal variability of the Kuroshio Extension (KE) jet using satellite altimeter observations from 1993 to 2010. The leading empirical orthogonal function (EOF) mode of sea level variability in the KE region represents the meridional shift of the KE jet, followed by its strength changes with a few month lag. This shift of the KE jet lags atmospheric fluctuations over the eastern North Pacific by about three years. Broad sea level anomalies (SLAs) emerge in the eastern North Pacific 3-4 years before the upstream KB jet shift, and propagate westward along the KE jet axis. In the course of the propagation, the meridional scale of the SLAs gradually narrows, and their amplitude increases. This westward propagation of SLAs with a speed of about 5 cm s(-1) is attributed to the westward propagation of the meridional shift of the jet, consistent with the thin-jet theory, whose importance has been suggested by previous numerical studies. In addition, the westward-propagating signals tend to conserve their quasigeostrophic potential vorticity anomaly, which may explain the characteristic changes of SLAs during the propagation. After the westward-propagating signals of positive (negative) SLAs reach at the east coast of Japan, the upstream KB jet strengthens (weakens) associated with the strength changes of the northern and southern recirculation gyres. Interestingly, this strength change of the KE jet propagates eastward with a speed of about 6 cm s(-1), suggesting an importance of advection by the current.
• Response of Storm Tracks to Bimodal Kuroshio Path States South of Japan

  Hirohiko Nakamura, Ayako Nishina, Shoshiro Minobe

  JOURNAL OF CLIMATE 25 21 7772 - 7779 2012年11月 [査読有り][通常論文]
   

  A large meridional shift of the sea surface temperature front occurs off the south coast of Japan associated with transitions between the large-meander and straight paths of the Kuroshio. Most extratropical cyclones generated in winter near the Kuroshio in the East China Sea pass through the region where the Kuroshio takes either the meander or the straight path. To examine whether such cyclones change their tracks and intensities according to the two states of the path, a new dataset of winter cyclone tracks derived from surface weather charts from the period 1969/70-2008/09 was produced. The composite analysis of cyclone tracks with respect to the meander and straight path states reveals the following: the cyclone track axis for the meander path state is located away from the south coast of Japan with a dispersive tendency, while that for the straight path state is attached to the south coast with a long extending feature. A difference in track between these two states also occurs to the east of Japan over the North Pacific. In addition, this behavior of the cyclone track is shown to be independent of the wintertime atmospheric circulation anomalies around Japan. The development rate of cyclones is 41% faster for the straight path state than the meander path state. Snowfall in Tokyo caused by south-coast cyclones is more frequent for the meander than the straight path state because the former state can act to decrease air temperature in Tokyo.
• Influence of the Kuroshio in the East China Sea on the Early Summer (Baiu) Rain

  Yoshi N. Sasaki, S. Minobe, T. Asai, M. Inatsu

  JOURNAL OF CLIMATE 25 19 6627 - 6645 2012年10月 [査読有り][通常論文]
   

  Influence of the Kuroshio in the East China Sea on the baiu rainband is examined using satellite observations, a reanalysis dataset, and a regional atmospheric model from 2003 to 2008. Satellite observations and reanalysis data reveal that precipitation over the Kuroshio is the highest in early summer (June), when the baiu rainband covers the East China Sea. The high rainfall is collocated with the warm sea surface temperature (SST) tongue of the Kuroshio. This locally enhanced precipitation is embedded in the large-scale baiu rainband, so that the amplitude of precipitation over the Kuroshio is twice as large as that in its surrounding area. The Kuroshio is also accompanied by high surface wind speed, energetic evaporation, and wind convergence. This wind convergence likely results from the SST influence on atmospheric pressure through not only temperature changes, but also humidity changes. Furthermore, the Kuroshio anchors the ascent motion and large diabatic heating with a peak in the midtroposphere, suggesting that the influence of the Kuroshio extends to the upper troposphere. It is also found that the East China Sea in June is the region of the strongest deep atmospheric response to western boundary currents along with the Gulf Stream region in summer. The observational results are well reproduced by the regional atmospheric model. The model indicates that when the SST tongue of the Kuroshio is smoothed, the enhanced precipitation, the energetic evaporation, and the wind convergence over the Kuroshio disappear, although the large-scale structure of the baiu rainband is not essentially changed.
• Decadal variability of the upper ocean heat content in the East/Japan Sea and its possible relationship to northwestern Pacific variability

  Hanna Na, Kwang-Yul Kim, Kyung-Il Chang, Jong Jin Park, Kuh Kim, Shoshiro Minobe

  JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS 117 C02017  2012年02月 [査読有り][通常論文]
   

  The upper ocean heat content variability in the East/Japan Sea was investigated using a 40 year temperature and salinity data set from 1968 to 2007. Decadal variability was identified as the dominant mode of variability in the upper ocean (0-300 m) aside from the seasonal cycle. The decadal variability is strong to the west of northern Honshu, west of the Tsugaru Strait, and west of southern Hokkaido. Temperature anomalies at 50-125 m exhibit a large contribution to the decadal variability, particularly in the eastern part of the East/Japan Sea. The vertical structure of regressed temperature anomalies and the spatial patterns of regressed 10 degrees C isotherms in the East/Japan Sea suggest that the decadal variability is related to upper ocean circulation in the East/Japan Sea. The decadal variability also exhibits an increasing trend, which indicates that the regions showing large decadal variations experienced warming on decadal time scales. Further analysis shows that the decadal variability in the East/ Japan Sea is not locally isolated but is related to variability in the northwestern Pacific.
• Diagnostics for near-surface wind convergence/divergence response to the Gulf Stream in a regional atmospheric model

  Kohei Takatama, Shoshiro Minobe, Masaru Inatsu, R. Justin Small

  ATMOSPHERIC SCIENCE LETTERS 13 1 16 - 21 2012年01月 [査読有り][通常論文]
   

  This study proposes a novel diagnostics for near-surface wind responses to oceanic fronts. By separating two roles of wind stress, i.e. downward momentum input and the surface friction, the diagnostics can express near-surface winds as a sum of terms relating to pressure adjustment, downward momentum mixing, and horizontal advection. The diagnostics are applied to the climatological wind convergence/divergence over the Gulf Stream obtained from a regional atmospheric model. It is found that the pressure adjustment plays a primary role and is mainly responsible for the convergence, while the downward momentum mixing is a secondary contributing factor to the divergence. Copyright (c) 2011 Royal Meteorological Society
• Decadal variability of the upper ocean heat content in the East/Japan Sea and its possible relationship to northwestern Pacific variability

  Hanna Na, Kwang-Yul Kim, Kyung-Il Chang, Jong Jin Park, Kuh Kim, Shoshiro Minobe

  Journal of Geophysical Research: Oceans 117 2 2012年 [査読有り][通常論文]
   

  The upper ocean heat content variability in the East/Japan Sea was investigated using a 40 year temperature and salinity data set from 1968 to 2007. Decadal variability was identified as the dominant mode of variability in the upper ocean (0-300 m) aside from the seasonal cycle. The decadal variability is strong to the west of northern Honshu, west of the Tsugaru Strait, and west of southern Hokkaido. Temperature anomalies at 50-125 m exhibit a large contribution to the decadal variability, particularly in the eastern part of the East/Japan Sea. The vertical structure of regressed temperature anomalies and the spatial patterns of regressed 10C isotherms in the East/Japan Sea suggest that the decadal variability is related to upper ocean circulation in the East/Japan Sea. The decadal variability also exhibits an increasing trend, which indicates that the regions showing large decadal variations experienced warming on decadal time scales. Further analysis shows that the decadal variability in the East/Japan Sea is not locally isolated but is related to variability in the northwestern Pacific. Copyright 2012 by the American Geophysical Union.
• Global analysis of the pressure adjustment mechanism over sea surface temperature fronts using AIRS/Aqua data

  Teruhisa Shimada, Shoshiro Minobe

  GEOPHYSICAL RESEARCH LETTERS 38 2011年03月 [査読有り][通常論文]
   

  We investigate the signatures of atmospheric pressure adjustment mechanism for surface wind convergence/divergence over major sea surface temperature (SST) frontal regions using global observations of satellite sounding and scatterometer. Lower tropospheric air thickness, which includes a sea-level pressure component modified by air temperature in the marine atmospheric boundary layer, is analyzed, and the relation between the Laplacian of the thickness and wind convergence are examined. Among four SST frontal regions in mid-latitudes, correlation between the thickness Laplacian and wind convergence is the largest over the Gulf Stream followed by those for the Agulhas Return Current and for the Brazil/Malvinas Current, and relatively small but still significant over the Kuroshio-Oyashio Extension. These correlations strongly suggest that the pressure adjustment mechanism ubiquitously plays an important role in air-sea interaction over the global SST frontal regions. Furthermore, air temperatures in the first two regions exhibit SST-relating signatures even in the mid-troposphere. Citation: Shimada, T., and S. Minobe (2011), Global analysis of the pressure adjustment mechanism over sea surface temperature fronts using AIRS/Aqua data, Geophys. Res. Lett., 38, L06704, doi:10.1029/2010GL046625.
• Permanent El Niño during the Pliocene warm period.

  Tsuyoshi Watanabe, Atsushi Suzuki, Shoshiro Minobe, Tatsunori Kawashima, Koji Kameo, Kayo Minoshima, Yolanda M. Aguilar, Ryoji Wani, Hodaka Kawahata, Kohki Sowa, Takaya Nagai, Tomoki Kase

  NATURE 471 7337 209 - 211 2011年03月 [査読有り][通常論文]
   

  The El Nino/Southern Oscillation (ENSO) system during the Pliocene warm period (PWP; 3-5 million years ago) may have existed in a permanent El Nino state with a sharply reduced zonal sea surface temperature (SST) gradient in the equatorial Pacific Ocean(1). This suggests that during the PWP, when global mean temperatures and atmospheric carbon dioxide concentrations were similar to those projected for near-term climate change(2), ENSO variability-and related global climate teleconnections-could have been radically different from that today. Yet, owing to a lack of observational evidence on seasonal and interannual SST variability from crucial low-latitude sites, this fundamental climate characteristic of the PWP remains controversial(1,3-10). Here we show that permanent El Nino conditions did not exist during the PWP. Our spectral analysis of the delta(18)O SST and salinity proxy, extracted from two 35-year, monthly resolved PWP Porites corals in the Philippines, reveals variability that is similar to present ENSO variation. Although our fossil corals cannot be directly compared with modern ENSO records, two lines of evidence suggest that Philippine corals are appropriate ENSO proxies. First, delta(18)O anomalies from a nearby live Porites coral are correlated with modern records of ENSO variability. Second, negative-delta(18)O events in the fossil corals closely resemble the decreases in delta(18)O seen in the live coral during El Nino events. Prior research advocating a permanent El Nino state may have been limited by the coarse resolution of many SST proxies, whereas our coral-based analysis identifies climate variability at the temporal scale required to resolve ENSO structure firmly.
• Reproductive success of planktivorous seabirds in the North Pacific is related to ocean climate on decadal scales

  Alexander L. Bond, Ian L. Jones, William J. Sydeman, Heather L. Major, Shoshiro Minobe, Jeffrey C. Williams, G. Vernon Byrd

  MARINE ECOLOGY PROGRESS SERIES 424 205 - U218 2011年 [査読有り][通常論文]
   

  Growing evidence indicates relationships between seabird demography and both large- and small-scale variation in climate and oceanography, yet few studies have examined multiple species and locations simultaneously. As secondary consumers, least, whiskered, and crested auklets (Aethia pusilla, A. pygmaea, and A. cristatella, respectively), congeneric planktivorous seabirds endemic to the Bering and Okhotsk seas, are expected to respond to changes in ocean climate due to their low trophic positioning. From 1990 to 2008, we measured reproductive success (productivity) and breeding phenology (mean hatching date) of auklets on Buldir, Kiska, and Kasatochi, 3 islands spanning 585 km across the Aleutian Islands, Alaska, USA. A model including Island, Species, and Winter Aleutian Low Pressure Index (ALPI) best explained productivity, with reproductive success decreasing among all species with increasing ALPI (beta = -0.273 +/- 0.0263 [SE]), likely through control of water temperature and prey (zooplankton) availability. Auklet productivity also increased with increasing winter sea surface temperature (SST) in the western North Pacific and western Bering Sea (and correspondingly decreased with increasing SST in the Gulf of Alaska), and was correlated negatively with spring sea-level air pressure in the North Pacific. These responses are reflective of positive values of the Aleutian low pressure system. Though our datasets cover only 19 yr or less, we found similar correlations between climate and auklet productivity among all species and islands. Together, our results suggest that ocean climatic conditions and reproductive success of planktivorous auklets are significantly related.
• Interannual variability of the Korea Strait Bottom Cold Water and its relationship with the upper water temperatures and atmospheric forcing in the Sea of Japan (East Sea)

  Hanna Na, Kwang-Yul Kim, Kyung-Il Chang, Kuh Kim, Jae-Yul Yun, Shoshiro Minobe

  JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS 115 C09031  2010年09月 [査読有り][通常論文]
   

  A 35 yearlong temperature data set is analyzed to investigate the long-term temperature variability in the Korea Strait and its relationship with the temperature variability in the upper layer of the Sea of Japan (East Sea). The second cyclostationary empirical orthogonal function mode of the vertical temperature section in the Korea Strait describes the interannual variability of the Korea Strait Bottom Cold Water (KSBCW). According to the corresponding principal component time series, the strength of the KSBCW fluctuates yearly with a major spectral peak around 3 years. Multiple regression analysis shows that the interannual KSBCW variability is closely linked with the temperature variability in the southwestern region of the Sea of Japan (East Sea) at about 50-100 m depth. Along 40 degrees N, the source of the KSBCW is traced at about 50 m, extending eastward from the east coast of Korea to about 135 degrees E. At 37 degrees N, the source is traced at a deeper level (about 50-100 m), confined more toward the east coast of Korea with a hint of double core characteristics. The interannual KSBCW variability is also related to the southward wind stress along the east coast of Korea. It appears that strong cooling/warming of upper water temperature induced by the basin-scale wind stress results in the interannual KSBCW variability. This connection is verified by showing a reasonable interannual covariability between the KSBCW and the basin-scale wind stress.
• Atmospheric Response to the Gulf Stream: Seasonal Variations

  Shoshiro Minobe, Masato Miyashita, Akira Kuwano-Yoshida, Hiroki Tokinaga, Shang-Ping Xie

  JOURNAL OF CLIMATE 23 13 3699 - 3719 2010年07月 [査読有り][通常論文]
   

  The atmospheric response to the Gulf Stream front in sea surface temperature is investigated using high-resolution data from satellite observations and operational analysis and forecast. Two types of atmospheric response are observed with different seasonality and spatial distribution. In winter, surface wind convergence is strong over the Gulf Stream proper between Cape Hatteras and the Great Banks, consistent with atmospheric pressure adjustments to sea surface temperature gradients. The surface convergence is accompanied by enhanced precipitation and the frequent occurrence of midlevel clouds. Local evaporation and precipitation are roughly in balance over the Florida Current and the western Gulf Stream proper. In summer, strong precipitation, enhanced high clouds, and increased lightning flash rate are observed over the Florida Current and the western Gulf Stream proper, without seasonal surface convergence enhancement. For the precipitation maximum over the Florida Current, local evaporation supplies about half of the water vapor, and additional moisture is transported from the south on the west flank of the North Atlantic subtropical high. Atmospheric heating estimated by a Japanese reanalysis reveals distinct seasonal variations. In winter, a shallow-heating mode dominates the Gulf Stream proper, with strong sensible heating in the marine atmospheric boundary layer and latent heating in the lower troposphere. In summer, a deep-heating mode is pronounced over the Florida Current and the western Gulf Stream proper, characterized by latent heating in the middle and upper troposphere due to deep convection. Possible occurrences of these heating modes in other regions are discussed.
• Precipitation Response to the Gulf Stream in an Atmospheric GCM

  Akira Kuwano-Yoshida, Shoshiro Minobe, Shang-Ping Xie

  JOURNAL OF CLIMATE 23 13 3676 - 3698 2010年07月 [査読有り][通常論文]
   

  The precipitation response to sea surface temperature (SST) gradients associated with the Gulf Stream is investigated using an atmospheric general circulation model. Forced by observed SST, the model simulates a narrow band of precipitation, surface convergence, and evaporation that closely follows the Gulf Stream, much like satellite observations. Such a Gulf Stream rainband disappears in the model when the SST front is removed by horizontally smoothing SST. The analysis herein shows that it is convective precipitation that is sensitive to SST gradients. The Gulf Stream anchors a convective rainband by creating surface wind convergence and intensifying surface evaporation on the warmer flank. Deep convection develops near the Gulf Stream in summer when the atmosphere is conditionally unstable. As a result, a narrow band of upward velocity develops above the Gulf Stream throughout the troposphere in summer, while it is limited to the lower troposphere in other seasons.
• A semi-analytical model of barotropic and baroclinic flows for an open Panama Gateway

  Hiroshi Sumata, Shoshiro Minobe, Tatsuo Motoi, Wing-Le Chan

  DYNAMICS OF ATMOSPHERES AND OCEANS 50 1 55 - 77 2010年06月 [査読有り][通常論文]
   

  A semi-analytical model of the Panama throughflow is presented. The model expresses the throughflow transport as a function of deep water formation in the North Pacific and in the North Atlantic, and of the Panama Gateway depth. The model is derived from the integral of the momentum equation along a circumpolar path, and can be interpreted from the point of view of the vorticity balance. The important conditions are whether the deep water, whose location is considered to be above the bottom water formed around Antarctica, originates from the North Atlantic or from the North Pacific, and whether the Panama Gateway is shallower than the lower boundary of the deep water. The present model indicates that the barotropic transport through the Panama Gateway is eastward, except for the case where the deep water is formed in the North Pacific and the sill of the Panama Gateway is shallow. The baroclinic structure of the Panama throughflow depends on whether the deep water is formed in the North Pacific or in the North Atlantic. These qualitative implications of the model are consistent with recent numerical studies and proxy-based paleoceanographic studies. Numerical experiments performed in the present study reinforce confidence in the semi-analytical model. (C) 2009 Elsevier B.V. All rights reserved.
• Coupled Ocean-Atmosphere Response to Idealized Freshwater Forcing over the Western Tropical Pacific

  Lixin Wu, Yan Sun, Jiaxu Zhang, Liping Zhang, Shoshiro Minobe

  JOURNAL OF CLIMATE 23 7 1945 - 1954 2010年04月 [査読有り][通常論文]
   

  The coupled ocean atmosphere responses to idealized freshwater forcing in the western tropical Pacific are studied using a fully coupled climate model. The model explicitly demonstrates that freshwater forcing in the western tropical Pacific can lead to a basinwide response with the pattern resembling the Pacific decadal oscillation. In the tropics, a negative (positive) freshwater forcing over the western tropical Pacific decreases (increases) sea surface height locally, and sets up a positive (negative) zonal pressure gradient anomaly, which accelerates (decelerates) the meridional overturning circulation and equatorial surface westward flow. This leads to an intensification (reduction) of meridional heat divergence and vertical cold advection, and thus a development of La Nina (El Nino)-like responses in the tropics. The tropical responses are further substantiated by the positive Bjerknes feedback, and subsequently force significant changes in the extratropical North Pacific through atmospheric teleconnection. The local freshwater response also reinforces the imposed Forcing, forming a positive feedback loop. Applications to Pacific climate changes are discussed.
• Interannual variability of the Korea Strait Bottom Cold Water and its relationship with the upper water temperatures and atmospheric forcing in the Sea of Japan (East Sea)

  Hanna Na, Kwang-Yul Kim, Kyung-Il Chang, Kuh Kim, Jae-Yul Yun, Shoshiro Minobe

  Journal of Geophysical Research: Oceans 115 9 2010年 [査読有り][通常論文]
   

  A 35 yearlong temperature data set is analyzed to investigate the long-term temperature variability in the Korea Strait and its relationship with the temperature variability in the upper layer of the Sea of Japan (East Sea). The second cyclostationary empirical orthogonal function mode of the vertical temperature section in the Korea Strait describes the interannual variability of the Korea Strait Bottom Cold Water (KSBCW). According to the corresponding principal component time series, the strength of the KSBCW fluctuates yearly with a major spectral peak around 3 years. Multiple regression analysis shows that the interannual KSBCW variability is closely linked with the temperature variability in the southwestern region of the Sea of Japan (East Sea) at about 50-100 m depth. Along 40°N, the source of the KSBCW is traced at about 50 m, extending eastward from the east coast of Korea to about 135°E. At 37°N, the source is traced at a deeper level (about 50-100 m), confined more toward the east coast of Korea with a hint of double core characteristics. The interannual KSBCW variability is also related to the southward wind stress along the east coast of Korea. It appears that strong cooling/warming of upper water temperature induced by the basin-scale wind stress results in the interannual KSBCW variability. This connection is verified by showing a reasonable interannual covariability between the KSBCW and the basin-scale wind stress. Copyright 2010 by the American Geophysical Union.
• Oyashio.

  Chiba Sanae, Hirawake T, Ishizaki S, Ito S, Kamiya H, Kaeriyama M, Kuwata A, Midorikawa T, Minobe S, Okamoto S, Okazaki Y, Ono T, Saito H, Saitoh S, Sasano D, Tadokoro K, Takahashi K, Takatani Y, Watanabe Y, Watanabe Y.W, Watanuki Y, Yamamuro O, Yamashita N, Yatsu A, McKinnell S.M, Dagg M.J

  Marine ecosystems of the North Pacific Ocean, 2003-2008. [PICES Special Publication No 4.] 302 - 329 2010年 [査読有り][通常論文]
  
• Climate-forced seasonal mismatch between the hatching of rhinoceros auklets and the availability of anchovy

  Yutaka Watanuki, Motohiro Ito, Tomohiro Deguchi, Shoshiro Minobe

  MARINE ECOLOGY PROGRESS SERIES 393 259 - 271 2009年 [査読有り][通常論文]
   

  Predator-prey relationships are key to understanding complex marine ecosystem dynamics. The match-mismatch hypothesis posits that predators time energy-intensive activities, such as reproduction, to periods of high food availability. However, predators may be constrained by various ecological or physiological processes, leading to mistimed activities relative to prey availability. We investigated inter-annual variation in the timing of breeding for a piscivorous seabird (rhinoceros auklet Cerorhinca monocerata) in relation to availability of a preferred prey item, Japanese anchovy Engraulis japonicus, using data collected over 18 yr between 1984 and 2006 at Teuri Island in the northern Japan Sea. Our primary goals were (1) to identify the climatic factors that affect the seabirds' timing of breeding, proxied by hatching date, and anchovy seasonal availability, and (2) to quantify the fitness effects of predator-prey matches and mismatches relative to climate variability. Hatching date was later in years with lower spring air temperatures. Auklets switched their feeding from sandlance and juvenile greenling to anchovy when it was transported into the birds' foraging range with the seasonal northern expansion of 13 degrees C warm water from the south. The mismatch between hatching date and the period of high anchovy availability was most pronounced when spring air temperatures were warm, and there was a weak Tsushima (warm) Current. Spring air temperature was influenced by spring atmospheric pressure gradients in the Arctic and northern Eurasia, which drive the east Asian winter monsoon, whereas timing of the Tsushima warm water expansion was influenced by winter surface pressures over the western North Pacific. Chick growth rates, mass at fledging, and overall fledging success (fitness) were lower during mismatch years when the auklets fed less on anchovy. The auklets were constrained to adjust hatching date because the seasonal mismatch appeared to be driven by independent and unpredictable surface pressure patterns.
• Responses of piscivorous seabirds at the Pribilof Islands to ocean climate

  G. Vernon Byrd, William J. Sydeman, Heather M. Renner, Shoshiro Minobe

  DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY 55 16-17 1856 - 1867 2008年08月 [査読有り][通常論文]
   

  Climate variability and change are expected to influence the seasonal cycle in North Pacific sub-arctic marine ecosystems. The hypothesis that timing of nesting and productivity of piscivorous seabirds [kittiwakes (Rissa tridactyla and Rissa brevirostris) and murres (Uria aalge and Uria lomvia)] at the Pribilof Islands are related to variation in ocean climate as indexed by changes in sea-ice concentrations (SICs) and sea-surface temperatures (SSTs) was tested. To test this hypothesis, timing and productivity of the seabirds were correlated with the winter sea-ice extent, defined as area-averaged SICs, and with winter, spring, and summer SST near the Pribilofs over a 32-yr period, 1975-2006. Timing and productivity for the two species of kittiwake were strongly correlated with each other and between the two breeding locations, St. George and St. Paul islands. Similar results were found for the two species of murres, although kittiwakes and murres were not strongly correlated with each other. Kittiwakes bred progressively earlier, advancing their hatching dates by 0.58 to 0.88d/yr over the study period. In contrast, there were no overall trends for murres, with the exception of thick-billed murres at St. Paul that nested progressively later, delaying breeding by 0.47 d/yr. Because of these trends, residuals from quadratic regressions were used to "detrend" the data (including cases where no significant trend was observed) for interannual comparisons with climate variables. Detrended kittiwake timing was inversely correlated with maximum SIC and positively correlated with winter SST. We found no strong relationships between the timing of murre nesting and SIC or SST with either raw or detrended data. Both raw and detrended data revealed a positive relationship between kittiwake productivity and SIC, and an inverse relationship with winter and spring SST. Murre productivity was correlated negatively with summer SST, but unrelated to SST in other seasons and to SIC. Timing and productivity were correlated inversely for murres and kittiwakes at both sites, but were significant only for raw (i.e. non-detrended) murre data and for detrended kittiwake data. Detrending emphasizes high-frequency (interannual) variability by suppressing low-frequency (interdecadal) variability, indicating that low-frequency change in murre timing has an effect on productivity, whereas interannual variation is responsible for the timing-productivity relationship for kittiwakes. These contrasting responses of surface-foraging kittiwakes and deep-diving murres provide insight into how the eastern Bering Sea ecosystem is responding to climate variability and change, and suggest that the food web has changed more substantially in the upper water column than at depth. Published by Elsevier Ltd.
• Air-sea interaction over ocean fronts and eddies

  R. J. Small, S. P. deSzoeke, S. P. Xie, L. O'Neill, H. Seo, Q. Song, P. Cornillon, M. Spall, S. Minobe

  DYNAMICS OF ATMOSPHERES AND OCEANS 45 3-4 274 - 319 2008年08月 [査読有り][通常論文]
   

  Air-sea interaction at ocean fronts and eddies exhibits positive correlation between sea surface temperature (SST), wind speed, and heat fluxes out of the ocean, indicating that the ocean is forcing the atmosphere. This contrasts with larger scale climate modes where the negative correlations suggest that the atmosphere is driving the system. This paper examines the physical processes that lie behind the interaction of sharp SST gradients and the overlying marine atmospheric boundary layer and deeper atmosphere, using high resolution satellite data, field data and numerical models. The importance of different physical mechanisms of atmospheric response to SST gradients, such as the effect of surface stability variations on momentum transfer, pressure gradients, secondary circulations and cloud cover will be assessed. The atmospheric response is known to create small-scale wind stress curl and divergence anomalies, and a discussion of the feedback of these features onto the ocean will also be presented. These processes will be compared and contrasted for different regions such as the Equatorial Front in the Eastern Pacific, and oceanic fronts in mid-latitudes such as the Gulf Stream, Kuroshio, and Agulhas Return Current. (C) 2008 Elsevier B.V. All rights reserved.
• Decadal sea level variability in the South Pacific in a global eddy-resolving ocean model hindcast

  Yoshi N. Sasaki, Shoshiro Minobe, Niklas Schneider, Takashi Kagimoto, Masami Nonaka, Hideharu Sasaki

  JOURNAL OF PHYSICAL OCEANOGRAPHY 38 8 1731 - 1747 2008年08月 [査読有り][通常論文]
   

  Sea level variability and related oceanic changes in the South Pacific from 1970 to 2003 are investigated using a hindcast simulation of an eddy-resolving ocean general circulation model (OGCM) for the Earth Simulator (OFES), along with sea level data from tide gauges since 1970 and a satellite altimeter since 1992. The first empirical orthogonal function mode of sea level anomalies (SLAs) of OFES exhibits broad positive SLAs over the central and western South Pacific. The corresponding principal component indicates roughly stable high, low, and high SLAs, separated by a rapid sea level fall in the late 1970s and sea level rise in the late 1990s, consistent with tide gauge and satellite observations. These decadal changes are accompanied by circulation changes of the subtropical gyre at 1000-m depth, and changes of upper-ocean zonal current and eddy activity around the Tasman Front. In general agreement with previous related studies, it is found that sea level variations in the Tasman Sea can be explained by propagation of long baroclinic Rossby waves forced by wind stress curl anomalies, if the impact of New Zealand is taken into account. The corresponding atmospheric variations are associated with decadal variability of El Nino-Southern Oscillation (ENSO). Thus, decadal sea level variability in the western and central South Pacific in the past three and half decades and decadal ENSO variability are likely to be connected. The sea level rise in the 1990s, which attracted much attention in relation to the global warming, is likely associated with the decadal cooling in the tropical Pacific.
• North Pacific regime shifts: Definitions, issues and recent transitions

  James Overland, Sergei Rodionov, Shoshiro Minobe, Nicholas Bond

  PROGRESS IN OCEANOGRAPHY 77 2-3 92 - 102 2008年05月 [査読有り][通常論文]
   

  The many recent publications on regimes and shifts highlight the importance of decadal variability in understanding climate and ecosystems and their connectivity. This paper explores several issues in the application of regime concepts. Even the definition of regimes is unclear, as usage by different authors highlight: (1) displacement or shifts in timeseries, (2) underlying mechanisms, and (3) the distinction between external forcing and internal reorganization of ecosystems. Such differences arise, and cannot be easily resolved, because of the relatively short duration of available physical and biological timeseries, and the complexity of multivariate process in marine systems with unknown variables and relationships. Climate indices often show a rather Gaussian distribution of values with a single mean, rather than clearly separated discrete multiple states. These physical indices can be represented by a red noise long memory process, where the index can, in fact, deviate substantially from the long term mean for multiple years. If we consider changes in timeseries themselves, then climate variables for the North Pacific display shifts near 1977,1989 and 1998. Recent variability suggests considerable uncertainty in the current state of the North Pacific. Biological variables often show a broader distribution of shifts over time, which is consistent with different types of responses to climate for different ecosystem elements and the importance of time lags in response to changes in physical forcing. Our current understanding of regime shifts is not a deterministic one, and while one can discuss amplitudes and mean duration of regimes, we cannot predict their precise timing other than to say that they will be a main feature of future climate and ecosystem states. While the authors believe that a single definition for regimes is currently not possible, the concept continues to be useful in moving the discussion of ecosystems away from the assumptions of single species and stationary processes. Published by Elsevier Ltd.
• Influence of the Gulf Stream on the troposphere

  Shoshiro Minobe, Akira Kuwano-Yoshida, Nobumasa Komori, Shang-Ping Xie, Richard Justin Small

  NATURE 452 7184 206 - U51 2008年03月 [査読有り][通常論文]
   

  The Gulf Stream transports large amounts of heat from the tropics to middle and high latitudes, and thereby affects weather phenomena such as cyclogenesis(1,2) and low cloud formation(3). But its climatic influence, on monthly and longer timescales, remains poorly understood. In particular, it is unclear how the warm current affects the free atmosphere above the marine atmospheric boundary layer. Here we consider the Gulf Stream's influence on the troposphere, using a combination of operational weather analyses, satellite observations and an atmospheric general circulation model(4). Our results reveal that the Gulf Stream affects the entire troposphere. In the marine boundary layer, atmospheric pressure adjustments to sharp sea surface temperature gradients lead to surface wind convergence, which anchors a narrow band of precipitation along the Gulf Stream. In this rain band, upward motion and cloud formation extend into the upper troposphere, as corroborated by the frequent occurrence of very low cloud- top temperatures. These mechanisms provide a pathway by which the Gulf Stream can affect the atmosphere locally, and possibly also in remote regions by forcing planetary waves(5,6). The identification of this pathway may have implications for our understanding of the processes involved in climate change, because the Gulf Stream is the upper limb of the Atlantic meridional overturning circulation, which has varied in strength in the past(7) and is predicted to weaken in response to human- induced global warming in the future(8).
• 北太平洋における気候の数十年スケール変動に関する研究，―2006年度堀内賞受賞記念講演―

  見延庄士郎

  天気 55 3 1731 - 1747 2008年 [査読有り][通常論文]
  
• Autumn atmospheric preconditioning for interannual variability of wintertime sea-ice in the Okhotsk Sea

  Yoshi N. Sasaki, Yurika Katagiri, Shoshiro Minobe, Ignatius G. Rigor

  JOURNAL OF OCEANOGRAPHY 63 2 255 - 265 2007年04月 [査読有り][通常論文]
   

  Relations in year-to-year variability between wintertime Sea-Ice Concentrations (SICs) IN in the Okhotsk Sea and atmospheric anomalies consisting of zonal and meridional 1000-hPa wind speeds and 850-hPa air temperatures are studied using a singular value decomposition analysis. It is revealed that the late autumn (October-Novemher) atmospheric conditions strongly influence sea-ice variability from the same season (late autumn) through late winter (February-March), in which sea-ice extent is at its maximum. The autumn atmospheric conditions for the positive sea-ice anomalies exhibit cold air temperature anomalies over the Okhotsk Sea and wind anomalies blowing into the Okhotsk Sea from Siberia. These atmospheric conditions yield anomalous ocean-to-atmosphere heat fluxes and cold sea surface temperature anomalies in the Okhotsk Sea. Hence, these results suggest that the atmospheric conditions affect the sea-ice through heat anomalies stored in sea-ice and oceanic fields. The late autumn atmosphere conditions are related to large 700-hPa geopotential height anomalies over the Bering Sea and northern Eurasia, which are related to a stationary Rossby wave propagation over the North Pacific and that from the North Atlantic to Eurasia, respectively. In addition, the late autumn atmospheric preconditioning also plays an important role in the decreasing trend in the Okhotsk sea-ice extent observed from 1980 to the mid-1990s. Based on the lagged sea-ice response to the late autumn atmosphere, a simple seasonal prediction scheme is proposed for the February-March sea-ice extent using four-month leading atmospheric conditions. This scheme explains 45% of the variance of the Okhotsk sea-ice extent.
• Intraseasonal variability of sea-ice-concentration in the Antarctic with particular emphasis on wind effect

  Kenji Baba, Shoshiro Minobe, Noriaki Kimura, Masaaki Wakatsuchi

  Journal of Geophysical Research: Oceans 111 12 2006年12月08日 [査読有り][通常論文]
   

  This study investigated mechanisms for the intraseasonal variability of sea-ice concentration in the Antarctic, using Complex Empirical Orthogonal Function (CEOF) analysis of daily sea-ice concentration data during the period 1992 through 2001 derived from images of the Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave Imager (SSM/I). The first CEOF mode clearly showed that the large amplitudes of sea-ice concentration occur in the marginal sea-ice zone of the western Antarctic. The first mode also revealed the existence of eastward propagating phases with a period of 10-20 days in the western Antarctic. Regression analysis of meridional wind velocity onto the temporal coefficient of the first CEOF mode showed that the spatial phase of the meridional wind velocity precedes that of sea-ice concentration by about 90 degrees, indicating that the maximum change of sea-ice concentration occurs at the maximum wind velocity. From data analyses of ice-drifting velocity and simple sea-ice model results, it is suggested that thermodynamical effects such as sea-ice production are likely to contribute dominantly to the intraseasonal variability of sea-ice concentration in the marginal sea-ice zone of the western Antarctic. Copyright 2006 by the American Geophysical Union.
• Intraseasonal variability of sea-ice concentration in the Antarctic with particular emphasis on wind effect

  Kenji Baba, Shoshiro Minobe, Noriaki Kimura, Masaaki Wakatsuchi

  JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS 111 C12 C12023 doi:10.1029/2005JC003052  2006年12月 [査読有り][通常論文]
   

  This study investigated mechanisms for the intraseasonal variability of sea-ice concentration in the Antarctic, using Complex Empirical Orthogonal Function (CEOF) analysis of daily sea-ice concentration data during the period 1992 through 2001 derived from images of the Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave Imager (SSM/I). The first CEOF mode clearly showed that the large amplitudes of sea-ice concentration occur in the marginal sea-ice zone of the western Antarctic. The first mode also revealed the existence of eastward propagating phases with a period of 10-20 days in the western Antarctic. Regression analysis of meridional wind velocity onto the temporal coefficient of the first CEOF mode showed that the spatial phase of the meridional wind velocity precedes that of sea-ice concentration by about 90 degrees, indicating that the maximum change of sea-ice concentration occurs at the maximum wind velocity. From data analyses of ice-drifting velocity and simple sea-ice model results, it is suggested that thermodynamical effects such as sea-ice production are likely to contribute dominantly to the intraseasonal variability of sea-ice concentration in the marginal sea- ice zone of the western Antarctic.
• Moisture balance for bidecadal variability of wintertime precipitation in the north pacific using NCEP/NCAR reanalysis

  T Nakanowatari, S Minobe

  JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN 83 4 453 - 469 2005年08月 [査読有り][通常論文]
   

  Moisture budgets are analyzed using National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis data over the North Pacific for a Bi-Decadal Oscillation (BDO) in precipitation that was reported by Minobe and Nakanowatari (2002). BDO in wintertime precipitation is mostly associated with moisture flux convergence, with a minor contribution from evaporation. The moisture convergence is mainly due to anomalies of wind and moisture on time scales longer than a month, except at high-latitudes where transient eddy (time scales shorter than a month) contributions are greater. When the Aleutian low strengthens (weakens), the anomalous moisture flux convergence is due to a cyclonic (anti-cyclonic) wind circulation over 30 degrees-60 degrees N and anti-cyclonic (cyclonic) wind circulation over 0 degrees-30 degrees N. This pair of anomalous circulations is also observed on inter-annual time scales, but they appear independent of El Nino/Southern Oscillation (ENSO). The anomalous circulation over 0 degrees-30 degrees N is associated with sea-level pressure anomalies in the tropics (20 degrees S-20 degrees N) and this result is confirmed with the International Comprehensive Ocean-Atmosphere Data Set (ICOADS) and the NCEP real-time marine data. This low-latitude anomalous circulation plays a dominant role in precipitation variability in Hawaii on the bi-decadal and interannual time scales.
• A 1 degrees monthly gridded sea-surface temperature dataset compiled from ICOADS from 1850 to 2002 and northern hemisphere frontal variability

  S Minobe, A Maeda

  INTERNATIONAL JOURNAL OF CLIMATOLOGY 25 7 881 - 894 2005年06月 [査読有り][通常論文]
   

  Using surface marine data collected in International Comprehensive Ocean Atmosphere Data Set (ICOADS) release 2.1, a gridded SST dataset on a monthly, 1 degrees x 1 degrees to grid is produced from 1850 to 2002. Some unrealistic features, which are commonly found in the gridded SSTs of ICOADS, are removed by a subjective quality control. Based on the gridded SST data, SST variability associated with the oceanic fronts is investigated for the North Atlantic and North Pacific. Year-to-year SST variability in the North Atlantic is prominent along the climatological Gulf Stream extension (GSE) in winter and spring. This correspondence is captured better in the present SST dataset than in several widely used datasets. GSE mean SST exhibits multidecadal variability similar to the Atlantic multidecadal oscillation represented by mean SSTs over the North Atlantic. Year-to-year SST variability in the North Pacific in winter and spring seasons is strong along the subarctic front (SAF) and also in the subtropical front (STF), with weaker amplitudes in the latter. In particular, just east of Japan, the Kuroshio extension appears to be a core of strong variability. Winter and spring averaged SAF and STF exhibit prominent decadal warmings in the 1940s, i.e. these fronts may be two of the action centres for the 1940s climate regime shift and the previously reported 1970s shift. The warming anomalies around the SAF associated with the 1940s shift are distributed more broadly than those with the 1970s shift, and have maximal amplitudes around Japan. Copyright (c) 2005 Royal Meteorological Society.
• Seasonally dependent interannual variability of sea ice in the Bering Sea and its relation to atmospheric fluctuations

  Yoshi N. Sasaki, Shoshiro Minobe

  Journal of Geophysical Research C: Oceans 110 5 1 - 11 2005年05月08日 [査読有り][通常論文]
   

  Interannual variability of sea ice in the Bering Sea and its relationship to atmospheric variability is analyzed using a singular value decomposition (SVD) analysis of sea ice concentrations (SICs) an 1000 hPa wind speeds in winter and spring seasons. The statistically significant first and second SVD modes, explaining 76.3% and 17.6% in winter and 54.6% and 29.6% in spring of the squared covariance between the two fields, are identified for SICs both in the winter and spring Seasons with 1 month leading wind speeds. The spatial structures show that the first (second) SVD mode explains the SIC variability in the northeastern (northwestern) Bering Sea, related to the local northwesterly (northerly) wind anomalies for the positive SIC anomalies both in the winter and spring seasons. A comparison of the first SVD modes between the winter and spring seasons suggests that the difference of dominant patterns of wind anomalies results in the difference of SIC anomaly distributions between two seasons. The relationship between sea ice and atmospheric circulation anomalies indicates that one mode of the leading two SVD modes in each season is related to large-scale atmospheric circulation associated with the Aleutian low and the other mode is related to relatively local atmospheric fluctuations related with pressure anomalies over Alaska. Furthermore, a slight difference of 700 hPa geopotential height anomalies results in the substantially different sea ice anomalies. These results suggest that in order to know the interannual sea ice variability in the Bering Sea, a better understanding of the wind anomalies over the Bering Sea are important. Copyright 2005 by the American Geophysical Union.
• Seasonally dependent interannual variability of sea ice in the Bering Sea and its relation to atmospheric fluctuations

  YN Sasaki, S Minobe

  JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS 110 C5 C05011  2005年05月 [査読有り][通常論文]
   

  Interannual variability of sea ice in the Bering Sea and its relationship to atmospheric variability is analyzed using a singular value decomposition (SVD) analysis of sea ice concentrations (SICs) and 1000 hPa wind speeds in winter and spring seasons. The statistically significant first and second SVD modes, explaining 76.3% and 17.6% in winter and 54.6% and 29.6% in spring of the squared covariance between the two fields, are identified for SICs both in the winter and spring seasons with 1 month leading wind speeds. The spatial structures show that the first (second) SVD mode explains the SIC variability in the northeastern (northwestern) Bering Sea, related to the local northwesterly (northerly) wind anomalies for the positive SIC anomalies both in the winter and spring seasons. A comparison of the first SVD modes between the winter and spring seasons suggests that the difference of dominant patterns of wind anomalies results in the difference of SIC anomaly distributions between two seasons. The relationship between sea ice and atmospheric circulation anomalies indicates that one mode of the leading two SVD modes in each season is related to large-scale atmospheric circulation associated with the Aleutian low and the other mode is related to relatively local atmospheric fluctuations related with pressure anomalies over Alaska. Furthermore, a slight difference of 700 hPa geopotential height anomalies results in the substantially different sea ice anomalies. These results suggest that in order to know the interannual sea ice variability in the Bering Sea, a better understanding of the wind anomalies over the Bering Sea are important.
• North Pacific halocline and cold climate induced by Panamanian Gateway closure in a coupled ocean-atmosphere GCM

  T Motoi, WL Chan, S Minobe, H Sumata

  GEOPHYSICAL RESEARCH LETTERS 32 10 L10618, doi:10.1029/2005GL022844  2005年05月 [査読有り][通常論文]
   

  The influence of the closure of the Panamanian Gateway during the late Cenozoic on climate in and around the North Pacific is investigated by using a coupled ocean-atmosphere general circulation model with an open and closed gateway. In the case of an open (closed) gateway, deep convection is present ( absent) in the North Pacific. The deep convection is associated with surface saline water transported from the subtropical Atlantic through the open gateway to the North Pacific. On the other hand, with the closed gateway, the lack of saline water transport from the Atlantic induces halocline formation over the subarctic Pacific with cold climate. The deep convection in the North Pacific leads to a vigorous thermohaline circulation with larger meridional heat transport, and causes warmer climate in and around the North Pacific. These results are generally consistent with paleoceanographic and paleoclimatic estimates related to the closure of the Panamanian Gateway.
• Numerical experiments of isolated convection under polynya

  N Okada, M Ikeda, S Minobe

  JOURNAL OF OCEANOGRAPHY 60 6 927 - 943 2004年12月 [査読有り][通常論文]
   

  The dense water formation process under polynya or lead is examined by numerical experiments using a three-dimensional non-hydrostatic model. Many numerical experiments on isolated convection in an initially homogeneous fluid have been performed for different sets of external parameters, in order to investigate a relationship between the convection process and the external parameters. The main focus is on the situation in which the horizontal length scale of disk-shaped buoyancy forcing (radius R) is comparable with the total water depth (H). The two dynamical regimes described in previous work-the baroclinically unstable convection and the baroclinically stable convection-are confirmed in the experiments. A horizontal shift of a convective chimney is important to a density anomaly in baroclinically stable convection. For the stable range, as R is reduced R/H < 0.7, a new regime is found, called "single-plume convection", in which multiple convective plumes do not fully develop, and the density anomaly scale has nearly no dependency on R. This change of dependency on R is consistent with that derived by scaling analysis. The non-hydrostatic component is more significant than the hydrostatic one in the single-plume convection. The information obtained is useful for parameterizing dense water formation under ice cover in a numerical model with a large grid size; i.e., the newly formed water has a density anomaly independent of the polynya size smaller than the water depth, while the anomaly increases as the size exceeds the depth.
• Interannual to interdecadal variability in the japan sea based on a new gridded upper water temperature dataset

  S Minobe, A Sako, M Nakamura

  JOURNAL OF PHYSICAL OCEANOGRAPHY 34 11 2382 - 2397 2004年11月 [査読有り][通常論文]
   

  A new gridded water temperature dataset of upper 400-m depths (0, 50, 100, 200, 300, and 400 m) for the Japan Sea ( or East Sea) is produced by using an optimal interpolation technique from 1930 to 1996, based on oceanographic observations collected in the World Ocean Database 1998. The temperature data are analyzed by a complex empirical orthogonal function (CEOF) with six levels combined using the data for a period from 1957 to 1996, during which most of gridded data are available. Before calculating the CEOFs, low-pass or high-pass filters (cutoff period at 7 yr) are applied to separate interannual and decadal temperature changes, respectively. One interannual and two decadal CEOF modes are identified. The interannual first CEOF mode is characterized by the energetic variability around and south of the subpolar front in the western Japan Sea, accompanied by northward and northeastward phase propagations emanating from the Tsushima Strait. The decadal first CEOF mode exhibits a broad structure prevailing over the whole Japan Sea, but large amplitudes are trapped by the subpolar front, with 60degrees-90degrees phase lags between the northeastern and southwestern Japan Sea. The decadal second CEOF mode has a localized structure with strong correlations in the Yamato Basin. The relation between the atmosphere and ocean is analyzed by a correlation analysis of wintertime sea level pressures (SLPs) onto the temporal coefficients of the CEOF modes. The interannual first CEOF mode is accompanied by the SLP anomalies over the western North Pacific Ocean with steep SLP gradients over the Japan Sea, suggesting that this mode is forced by local wind anomalies associated with the SLP changes over the western North Pacific. The decadal first CEOF mode is likely to be caused by changes of the east Asian winter monsoon due to the SLP variability of the northern part of the Siberian high, which is closely associated with the decadal fluctuations of the Arctic Oscillation and the North Atlantic Oscillation. The second decadal CEOF mode is accompanied by high SLP correlations over the central North Pacific associated with strength changes of Aleutian lows, suggestive of remote forcing from the central North Pacific.
• Generation of interannual and interdecadal climate oscillations through nonlinear subharmonic resonance in delayed oscillators

  S Minobe, FF Jin

  GEOPHYSICAL RESEARCH LETTERS 31 16 L16206, 10.1029/2004GL019776.*  2004年08月 [査読有り][通常論文]
   

  The resonant behavior of delayed oscillators is studied using two simple prototype equations similar to that used by Suarez and Schopf. One prototype equation has a periodic modulation of simultaneous feedback, and the other prototype equation has a periodic external forcing term. The periodic modulation yields even-multiple resonance to the modulation periods, while the periodic forcing results in odd-multiple resonance to the forcing periods. The reason why these two-types of resonance occur in each system is explained. The key mechanism for the resonance is that a positive simultaneous feedback for small amplitudes sets a threshold. Only when the sum of non-simultaneous terms is larger than the threshold, a phase reversal can take place. The implications of El Nino elimination due to annual cycle and potential importance for the decadal variability are discussed.
• Interannual to decadal variability in the southern Okhotsk Sea based on a new gridded upper water temperature data set

  S Minobe, M Nakamura

  JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS 109 C9 C09S05: doi:10.1029/2003JC001916.  2004年07月 [査読有り][通常論文]
   

  A new gridded water-temperature data set of upper 200 m depths (0, 50, 100, 200 m depths) for the Okhotsk Sea was produced using an optimal interpolation technique from 1950 to 1996 using oceanographic observations in the World Ocean Database 1998. Temperature variability at 50, 100 and 200 m depths in the southern Okhotsk Sea (south of 52degreesN) in the warm-season (May-October) was investigated by an Empirical Orthogonal Function (EOF) analysis from 1958 to 1994, for which sufficient data exist for an EOF analysis. The first EOF mode has a monopole structure with the maximal amplitude in the Kuril Basin, and the corresponding Principal Component (PC) exhibits prominent quasi-decadal variability. The first EOF mode is closely related with the wintertime (December-February) sea surface temperature anomalies over the subarctic front or Oyashio front in the North Pacific, and with wintertime Sea level Pressure (SLP) differences between northern Eurasia and the northern North Pacific. This suggests that the temperature changes in the Okhotsk Sea are caused by changes in the strength of the Asian winter monsoon, which are associated with the SLP difference. A quasi-decadal oscillation, similar to that of the PC-1, is observed in the SLP difference since the 1960s, and shared by the Polar/Eurasian (POL) pattern, Arctic Oscillation (AO) and North Atlantic Oscillation (NAO). Some hints of the relating variability are observed in coastal sea level difference between Wakkanai and Abashiri, which was used as a proxy for transport in the Soya Warm Current. Also, some features of sea ice extents co-vary with the PC-1.
• Updated assessments of the 1998/99 climate change over the north Pacific.

  Shoshiro Minobe

  In Neo-Science of Natural History: Integration of Geoscience and Biodiversity Studies, Proc. int. symp. 103 - 106 2004年 [査読有り][通常論文]
  
• Impact of Panamanian Gateway Opening on the Global Ocean Circulation.

  Sumata, H, S. Minobe, T. Motoi, W.-L. Chan

  Neo-Science of Natural History: Integration of Geoscience and Biodiversity Studies, 93 - 101 2004年 [査読有り][通常論文]
  
• Year-to-year variability in the Hadley and Walker circulations from NCEP/NCAR reanalysis data

  S Minobe

  Hadley Circulation: Present, Past and Future 21 153 - 171 2004年 [査読有り][通常論文]
   

  The year-to-year variability in the local Hadley and Walker circulations is studied by empirical orthogonal function (EOF) analysis of zonal and meridional divergent winds at 200 and 850 hPa in the NCEP/NCAR reanalysis data. The first mode of the EOF analysis for the period since 1979 is closely related to the El Nino/Southern Oscillation (ENSO). The corresponding vertical velocity structure at the middle of the troposphere is characterized by the combination of a horseshoe pattern in the western tropical Pacific and an oval pattern in the central-eastern equatorial Pacific, consistent with satellite-derived precipitation correlations. A streamline analysis for horizontal divergent winds and vertical winds revealed that the dominant local Hadley and Walker circulation anomalies connect the oval and the horseshoe, while the other clusters of the local Hadley circulation anomalies rotating in opposing directions emanate from the Maritime Continent region. The first EOF mode of the data for 1949 through 2002 is characterized by a trend-like increase from the 1960s to the 1980s that is consistent with a previous study by Goswami and Thomas (2000). This mode is accompanied by an increase of downward vertical wind anomalies over Sahel and over the central equatorial Pacific Ocean and by an increase in upward anomalies over the Maritime Continent and the Amazon. A consistent decrease in precipitation is observed over Sahel. Precipitation also decreased over the central Pacific, but the region of the decrease is located to the south of the center of the downward wind anomalies. Precipitation increases consistent with the local upward motions are not observed over the Maritime Continent or over the Amazon.
• Global structure of Bidecadal precipitation variability in boreal winter

  S Minobe, T Nakanowatari

  GEOPHYSICAL RESEARCH LETTERS 29 10 1396, doi 10.1029/2001GL014447, 22 May 2002.  2002年05月 [査読有り][通常論文]
   

  [1] Three global monthly precipitation datasets, including gauge measurements, gauge/satellite merged analysis (CMAP), and NCEP/NCAR reanalysis, are analyzed with respect to Bi-Decadal Oscillation (BDO) in boreal winter during the 20th century. Correlation and coherency analyses between the precipitations and the strength of the Aleutian low, which is an action center of the BDO, reveal substantial impacts of the BDO on precipitations around the Pacific Ocean. The covariability of the precipitations is prominent for Hawaii, mid-latitude eastern North America, Florida and eastern-China/Southern-Japan, and at some other regions including the Southern Hemisphere. The most coherent BDO precipitation pattern common to the CMAP and reanalysis features significant anomalies over the tropical (10degrees-30degreesN), central (30degrees-50degreesN) and northern (50degrees-70degreesN) North Pacific with alternating polarities. The influence of the BDO on Hawaii winter droughts and salinity in the North Pacific is discussed.
• Maximal wavelet filter and its application to bidecadal oscillation over the Northern Hemisphere through the twentieth century

  S Minobe, T Manabe, A Shouji

  JOURNAL OF CLIMATE 15 9 1064 - 1075 2002年05月 [査読有り][通常論文]
   

  Based on a wavelet transform, a new method referred to as maximal wavelet filter (MWF) is proposed to extract temporal structure changes of a climatic oscillation, which varies its pattern corresponding to the changes of the oscillation period. The MWF is a bandpass filter having a narrow pass band, the central frequency of which temporally varies according to the periods of maximal wavelet amplitudes for a specific region. MWF is applied to wintertime sea level pressures (SLPs) in the Northern Hemisphere from 1899 to 2000 to extract SLP changes associated with the bidecadal oscillation (BDO), which distributes globally but has the strongest amplitudes in the North Pacific. In the Pacific sector, the BDO center of action captured by the MWF was located over Alaska in the first few decades of the record, and then moved southward to the central North Pacific from 1920 to 1950, with maximal BDO amplitudes in the middle of the century. The southward migration was accompanied by the previously reported increase of the oscillation period from 15 to 20 years. On the other hand, Atlantic SLP variations coherent with the Pacific BDO had large amplitudes in midlatitudes (high latitudes) in the early (late) part of the twentieth century. In association with these spatial structure changes, the pattern of the recent BDO resembles the pattern of the Arctic Oscillation. The analysis of the sea surface temperatures (SSTs) gridded from the Comprehensive Ocean-Atmosphere Data Set (COADS) and the newly digitized Kobe collections suggests that BDO pattern in the SSTs also shifted toward the south between the first and last few decades of the twentieth century. Furthermore, covariability between the land-air temperatures and Aleutian low strength is observed through the twentieth century for Alaska, but only after 1940 for the midlatitudes of western North America and Hawaii, indicating that the BDO influence was limited to the high latitudes in the first few decades of the twentieth century in these regions, consistent with the spatial structure changes in the SLP field over the North Pacific.
• Interannual to interdecadal changes in the Bering Sea and concurrent 1998/99 changes over the North Pacific

  S Minobe

  PROGRESS IN OCEANOGRAPHY 55 1-2 45 - 64 2002年 [査読有り][通常論文]
   

  Sea-Surface Temperatures (SSTs), upper water Heat Storage (HS), Sea-Level Displacements (SLDs), Sea-Ice Concentration (SICs) in the Bering Seas and associated atmospheric circulations are analyzed to identify dominant interannual to interdecadal variations. As a representative time series of the SST variations, Principal Component (PC) of the first mode of a seasonally combined Empirical Orthogonal Function (EOF) is employed. The corresponding EOF (spatial pattern) exhibits the smallest amplitudes in winter and largest in summer. PC1 is characterized by a warming trend throughout the record (1921-2001) with the warmest year in 1997, which is followed by rapid cooling until 1999. The warming from 1995-1997 and cooling from 1997-1999 are commonly found in HS along the southern rim of the Bering Sea, and also accompanied by SLD rise and fall, respectively. The SIC variability corresponding to SST PC1 is prominent in the eastern Bering Sea in spring with correlations as high as 0.7, but good correlations were mainly observed prior to 1990. The correlations between the SST PC1 and sea-level pressures (SLPs) also suggest that the spring atmospheric circulation anomalies play an important role in the variations of the SST and sea-ice in the Bering Sea. The cooling and SLD fall in the late 1990s in the Bering Sea might be related with a possible major regime shift in 1998/1999, which was discussed by Minobe (2000), Hare and Mantua (2000), and Schwing and Moore (2000). In the 1998/99 change over the North Pacific, SSTs and HS increased abruptly both in the Kuroshio/Oyashio Extension region and the central North Pacific, accompanied by cooling in the eastern North Pacific. At the same time, SLDs rose from Japan to 160 W roughly along Kuroshio Extension path with a tongue-like structure. The tongue-like SLD rise is likely forced by wintertime atmospheric anomalies associated with SLP increase in the eastern North Pacific. (C) 2002 Elsevier Science Ltd. All rights reserved.
• Buoyancy- and wind-driven circulation in an extended model of potential vorticity homogenization

  S Nishino, S Minobe

  JOURNAL OF PHYSICAL OCEANOGRAPHY 30 9 2391 - 2403 2000年09月 [査読有り][通常論文]
   

  An analytical model is proposed on the middepth water circulation between the surface wind-driven circulation and the deep buoyancy-driven circulation. The model consists of three and a half layers, with the second and third layers being the middepth layers. The model includes thermohaline processes by allowing diapycnal flows at interfaces between layers, in addition to the potential vorticity homogenization proposed by Rhines and Young. The velocities of diapycnal flow are calculated from the density stratification, which can be given solely by a wind-driven model as a good approximation. The divergence of diapycnal velocity causes a circulation in addition to the wind-driven circulation. Although, in pure wind-driven theories, motion was absent outside the region of homogenized potential vorticity, the present model gives significant currents there. In particular, a prominent eastward flow appears in the third layer along the southern rim of the homogeneous potential vorticity region in the second laver. The flow pattern in the present model is consistent with that estimated diagnostically from the climatological density distribution in the North Pacific. The diagnosed flow field is further supported by the oxygen distribution there.
• Spatio-temporal structure of the pentadecadal variability over the North Pacific

  S Minobe

  PROGRESS IN OCEANOGRAPHY 47 2-4 381 - 408 2000年 [査読有り][通常論文]
   

  Using a Multi-Taper frequency domain-Singular Value Decomposition (MTM-SVD), a pentadecadal oscillation was detected in the winter-spring sea-level pressure (SLP) field over the North Pacific and surface air-temperature in North America which was significant at the 95% confidence level. The MTM-SVD captured the different SLP and ah-temperature distributions between the winter and spring seasons in a consistent manner. The pentadecadal SLP signature in the spring season is centered nearer the west coast of North America than in the winter season. This zonal displacement is consistent with the prominent springtime pentadecadal air-temperature variability in mid-latitude western North America. A wavelet analysis of the Pacific Decadal Oscillation index (PDOI) showed that the regime shifts in the 1920s, 1940s and 1970s involved simultaneous phase reversals of the bidecadal and pentadecadal variations. The two interdecadal variations are synchronized with one another such that a half period of the pentadecadal oscillation tone epoch of an individual regime) corresponds to one and half periods of the bidecadal oscillation. These results are consistent with the wavelet analysis of the North Pacific Index (NPI). Similar resonance between the bidecadal and pentadecadal variations is evident in air-temperatures over Alaska. The bidecadal and pentadecadal signals have different seasonality in these time series, suggesting that although the two interdecadal variations arise from two different physical mechanisms, they interact with each other. The most distinct seasonal difference was observed in mid-latitude western North America, where the bidecadal variation prevails only in the winter season and the pentadecadal variation only in the spring season. Alaska air-temperatures in the winter and winter-spring of 1999 were the coldest since 1977, as were springtime air-temperatures in mid-latitude western North America, in contrast to the warm anomalies that prevailed in this: region during 1977-98. The NPI and PDOI also exhibited an opposite polarity in 1999 to the respective regime mean polarities. These anomalous conditions in winter and spring seasons of 1999 may signify a major regime shift in 1998-1999. In order to verify whether or not a regime shift did occur in 1998-1999, a careful examination of additional data in coming ten or so years will he necessary. (C) 2000 Elsevier Science Ltd. All rights reserved.
• An introduction to the PICES symposium on the nature and impacts of North Pacific climate regime shifts

  Hare, SR, S Minobe, WS Wooster, S McKinnell

  PROGRESS IN OCEANOGRAPHY 47 2-4 99 - 102 2000年 [査読有り][通常論文]
  
• Plume Structures in Deep Convection of Rotating Fluid.

  Minobe, S, Y. Kanamoto, N. Okada, H. Ozawa, M. Ikeda

  Nagare Multimedia 2000 (internet journal) http://www.nagare.or.jp/mm/2000/minobe/index.htm  2000年 [査読有り][通常論文]
  
• Resonance in bidecadal and pentadecadal climate oscillations over the North Pacific: Role in climatic regime shifts

  S Minobe

  GEOPHYSICAL RESEARCH LETTERS 26 7 855 - 858 1999年04月 [査読有り][通常論文]
   

  The roles of interdecadal oscillations in climatic regime shifts, which are observed as rapid strength changes in the Aleutian low in winter and spring seasons, have been analyzed. A regime shift results from simultaneous phase reversals between pentadecadal and bidecadal variations, which synchronize with one another at a relative period of three. The pentadecadal variation, which is observed in both winter and spring seasons, provides the basic timescale of regime shifts, while the bidecadal variation, which is observed only in winter, characterizes the rapidity of the shifts. A Monte-Carlo simulation has shown that the simultaneous phase reversals or resonance between the pentadecadal and bidecadal variations reflect a physical linkage between them and do not coincide accidentally. The role of this synchronization feature for assessing and predicting regime shifts is discussed.
• Interdecadal variations in Japanese sardine and ocean/climate

  Yasuda, I, H Sugisaki, Y Watanabe, SS Minobe, Y Oozeki

  FISHERIES OCEANOGRAPHY 8 1 18 - 24 1999年03月 [査読有り][通常論文]
   

  Relations between the long-term variations in numbers of Japanese sardine and in ocean/climate were studied. We examined long-term records of the spring air temperature on the north-western coast of North America (ATNA; 40-50 degrees N, 130-110 degrees W) reconstructed from tree rings, and the sardine catch records inferred from documents dating from 1600 to 1990. High sardine catches occurred eight times in this period, and each high catch continued for 7-45 years. We found a significant difference in mean ATNAs between the abundant and poor catch periods: high (low) catch occurred in periods of high (low) ATNA. ATNA was negatively correlated with spring sea-surface temperature east of Japan (SSTJ; 36-40 degrees N, 150-160 degrees E), where the sardine possibly migrate north-eastward, a relation which was confirmed from 1940 to 1990. In years when the Aleutian Low Pressure System (AL) shifted south-east and intensified, the westerly wind was strong east of Japan along the south-western edge of the AL, resulting in low SSTJ; a warm southwesterly wind blows in the west coast of North America along the south-eastern edge of the AL. If we assume that this relation between ATNA and SSTJ can be extended Lack to the 1600s, high (low) catches occur in the period when SSTJ is low (high). This relation between sardine catch and SSTJ is consistent with previous studies based on data from after 1900. The present results suggest that long-term variations in Japanese sardine are related to interdecadal North Pacific ocean/climate variability.
• Interdecadal modulation of interannual atmospheric and oceanic variability over the North Pacific

  S Minobe, N Mantua

  PROGRESS IN OCEANOGRAPHY 43 2-4 163 - 192 1999年 [査読有り][通常論文]
   

  The interdecadal modulation of interannual variability of the atmosphere and ocean is examined over the North Pacific by using Wavelet Transform combined with Empirical Orthogonal Function (EOF) or Singular Value Decomposition (SVD) analysis. For the period of record 1899-1997, the interannual variability of the wintertime Aleutian Low, identified by either the North Pacific Index or the leading eigenvector (EOF-1) of North Pacific sea level pressure (SLP) exhibits an interdecadal modulation, Interannual variance in the strength of the Aleutian Low was relatively large from the mid-1920s to mid-1940s and in the mid-1980s, but relatively small in the periods from 1899 to the mid-1920s and from the mid-1940s to the mid-1970s. The periods of high (low) interannual variability roughly coincide with pentadecadal regimes having a time averaged relatively intense tweak) Aleutian Low. Consistent with this SLP variability the interannual variance in the zonal wind stress is strengthened in the central North Pacific after the 1970s. The SLP EOF-2, which is related to the North Pacific Oscillation, exhibited a strengthening trend from the beginning of this century to the mid-1960s. After the 1970s. the interannual variance of SLP EOF-2 is generally smaller than that in the period from 1930 to 1970, Similar interdecadal changes in interannual variance are found in expansion coefficients for the first two EOFs of the Pacific sector 500 hPa height field for the period 1946-1993, EOF-1 of Pacific sector 500 hPa corresponds to the Pacific/North American (PNA) teleconnection pattern, while EOF-2 is related to the Western Pacific (WP) pattern, The relative influence of the atmospheric PNA and WP interannual variability on North Pacific SSTs appears to have varied at pentadecadal time scales. Results from an SVD analysis of winter season (December-February) 500 hPa and North Pacific spring season (March-May) SST fields demonstrate that the PNA-related SST anomaly exhibited larger interannual variance after the 1970s. whereas the interannual variance of the WP related SST anomaly is larger before the 1970s. Correlations between the coastal North Pacific SST records and gridded atmospheric field data also change on interdecadal time scales. Our results suggest that the SST records from both the northwest and northeast Pacific coasts were more closely coupled with the PNA teleconnection pattern during the periods of 1925-1947 and 1977-1997 than in the regime from 1948 to 1976. Teleconnections between ENSO and preferred patterns of atmospheric variability over the North Pacific also appear to vary on interdecadal time scales. However, these variations do not reflect a unique regime-dependent influence. Our results indicate that ENSO is primarily related to the PNA (WP pattern in the first (last) half of the present century. Correlation coefficients between indices for ENSO and PNA-like atmospheric variability are remarkably weak in the period from 1948 to 1976. (C) 1999 Elsevier Science Ltd. All rights reserved.
• A 50-70 year climatic oscillation over the North Pacific and North America

  S Minobe

  GEOPHYSICAL RESEARCH LETTERS 24 6 683 - 686 1997年03月 [査読有り][通常論文]
   

  The chronology of interdecadal climatic regime shifts is examined, using instrumental data over the North Pacific, North America and the tropical oceans, and reconstructed climate records for North America, In the North Pacific and North America, climatic regime shifts around 1890 and in the 1920s with alternating polarities are detected, whose spatial structure is similar to that of the previously-known climatic shifts observed in the 1940s and 1970s. Sea-surface temperatures in the tropical Indian Ocean-maritime continent region exhibit changes corresponding to these four shifts. Spectra obtained by the Multi-Taper-Method suggest that these regime shifts are associated with 50-70 year climate variability over the North Pacific and North America. The leading mode of the empirical orthogonal functions of the air-temperature reconstructed from tree-rings in North America exhibits a spatial distribution that is reminiscent of instrumentally observed air-temperature differences associated with the regime shifts. The temporal evolution of this mode is characterized by a 50-70 year oscillation in the eighteenth and nineteenth centuries. This result, combined with the results of the analyses of the instrumental data, indicates that the 50-70 year oscillation is prevalent from the eighteenth century to the present in North America.
• Detection of an annual westward propagating signal in the meridional wind component along 8°N in the Pacific.

  S Minobe

  JOURNAL OF CLIMATE 9 7 1661 - 1668 1996年07月 [査読有り][通常論文]
   

  A westward propagating signal with the annual period is detected in anomalies of the zonally averaged meridional wind component along 8 degrees N across the Pacific Ocean. The propagating signal in the ''eddy'' (defined as the departure from the zonally averaged) meridional wind has approximately the same propagation speed as the well-known propagating signal in the zonal wind component along the equator, and the former has larger amplitude than the latter. The eddy SST gradient between the equator and 10 degrees N exhibits a similar westward propagation and is in phase with the eddy meridional wind; the northward eddy wind is accompanied by the warmer eddy SST to the north. The propagating features in both the eddy meridional wind and the SST gradient are quite regular from year to year, except for El Nino years. In the El Nino periods, the regular features are disturbed in the western Pacific, but the in-phase relationship between these two parameters still holds. These relationships indicate that the boundary-layer mechanism is most likely to be of primary importance in the response of the eddy meridional wind to the SST variations.
• ANNUAL PERIOD EQUATORIAL WAVES IN THE PACIFIC-OCEAN

  S MINOBE, K TAKEUCHI

  JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS 100 C9 18379 - 18392 1995年09月 [査読有り][通常論文]
   

  This paper analyzes behavior of annual period equatorial waves and their role in oceanic variations, namely, the sea level displacement, zonal current, and sea surface temperature (SST) along the equator in the Pacific. Using; a linear model forced by observed wind stress, the amplitudes and phases of the annual equatorial waves are calculated. The model equatorial waves are compared with the waves decomposed from Levitus' (1982) climatological density data. The modeled and decomposed first-meridional-mode Rossby waves of the two gravest vertical modes indicate common features that those waves are forced in the eastern Pacific and propagate to the central Pacific. These first-meridional-mode Rossby waves play a dominant role in the model sea level displacement and cause the westward propagating feature in the model surface zonal current in the central Pacific. The analysis suggests that the propagation of the surface zonal current is significantly responsible for the well-known westward propagation of annual SST variation in this region. The modeled and decomposed Kelvin waves are significantly different, but the model suggests that the role of the annual Kelvin waves in the equatorial oceanic variations is smaller than that of the first-meridional-mode Rossby waves.
• Analysis of wind forcing contributions to annual period sea-level displacement at the equator.

  Shoshiro Minobe

  TOGA-Notes (USA) 4 7 - 9 1991年 [査読有り][通常論文]
  

書籍

• 地球惑星科学入門

  在田 一則, 竹下 徹, 見延庄士郎, 渡部 重十編著 (担当:共著)
  北海道大学出版会 2010年
• 気象学と海洋物理学で用いられるデータ解析法, 気象研究ノート

  伊藤 久徳, 見延 庄士郎 (担当:共著)
  日本気象学会 2010年
• 理系のためのレポート・論文完全ナビ

  見延庄士郎 (担当:単著)
  講談社 2008年
• 物理的環境におけるレジーム・シフトと十年スケール変動のメカニズム. レジーム・シフト－気候変動と生物資源管理－

  川崎 健, 谷口 旭, 二平 章, 花輪 公雄, 見延庄士郎 (担当:共著範囲:45-61)
  成山堂 2007年
• 日本の気候変動と中高緯度の大気・海洋変動，in 海と環境：海が変わると地球が変わる

  見延庄士郎 (担当:共著範囲:88-98)
  日本海洋学会編, 講談社 2001年

講演・口頭発表等

• Ocean-to-atmosphere Influence in Mid-latitudes Revealed by Satellite Observations and Other High-resolution Data: Scale-separation Strategy.  [招待講演]

  Shoshiro Minobe

  AOGS annual meeting, 2014年07月
• Diurnal precipitation variability over the Gulf Stream and the Kuroshio. Climate implications of frontal scale air-sea interaction  [招待講演]

  Shoshiro Minobe, Shogo Takebayashi

  Climate implications of frontal scale air-sea interaction 2013年08月
• Regional secular trends in a new global gridded phosphate dataset  [招待講演]

  Shoshiro Minobe, Yutaka Hosoya

  WCRP/CLIVAR Second International Symposium on Boundary Current Dynamics 2013年07月
• Ocean to atmosphere feedback in mid-latitudes over western boundary currents  [招待講演]

  Shoshiro Minobe

  CLIVAR/WCRP Workshop on Decadal and Multi-decadal Variability in Pacific and Indian Ocean, First Institute of Oceanography in Qingdao 2012年09月
• Regional influence of basin-scale wind stress variability via jet-trapped Rossby waves in the western North Pacific.  [招待講演]

  Shoshiro Minobe, Yoshi N. Sasaki, Niklas Schneider, Yuji Miura

  International Workshop Development and Application of Regional Climate Models-II 2012年04月
• Regional secular trends in a new global gridded phosphate and oxygen dataset  [招待講演]

  Shoshiro Minobe, Yutaka Hosoya

  PICES 2011 2011年10月
• Influence of the Kuroshio in the East China Sea on the troposphere.  [招待講演]

  Minobe S, M. Miyashita, T. Asai, M. Inatsu, A. Kuwano-Yoshida, H. Tokinaga, S.-P. Xie

  In International Symposium on Boundary Current Dynamics: its connection with open-ocean and coastal processes and responses to global climate change 2010年05月
• Atmospheric response to the Gulf Stream: Seasonal variations.  [招待講演]

  Minobe S, M. Miyashita, A Kuwano-Yoshida, H. Tokinaga, S.-P Xie

  Ocean Science Meeting 2010年02月
• Meridional eddy heat transport estimations using satellite data and eddy resolving OGCM.  [招待講演]

  Minobe S, K. Aoki, Y. Tanimoto, Y. N. Sasaki, Y. Sasai

  Workshop for “Mesoscale eddies and their roles in North Pacific ecosystems” in PICES annual meeting 2009年10月
• Influence of the Kuroshio in the East China Sea on the atmosphere.  [招待講演]

  Minobe, S, T. Asai, M. Miyashita, K. Takatama, M. Inatsu

  The 15th Pacific-Asian Marginal Seas Meeting. 2009年04月
• Influence of the Gulf Stream on the troposphere.  [招待講演]

  Shoshiro Minobe

  U.S. CLIVAR Western Boundary Current Workshop. 2009年01月
• Anomalous SST warming over Kuroshio-Oyashio extensions from 1999 to 2001 and its possible ocean to atmosphere influence.  [通常講演]

  Shoshiro Minobe

  Climate Change: Past and Future. 2006年11月
• What is a Regime Shift? Semantics and recent indicators.  [招待講演]

  Overland, J, R. Rodionov, N. Bond, S. Minobe

  Climate variability and ecosystem impacts on the North Pacific: A basin-scale synthesis. 2006年04月
• Scale interactions of climate and marine ecosystems.  [招待講演]

  Shoshiro Minobe

  PICES/CLIVAR Workshop 2004年10月
• Pacific decadal variability: A review.  [招待講演]

  Minobe, S, N. Schneider, C. Deser, Z. Liu, N. Mantua, H. Nakamura, M. Nonaka

  CLIVAR 2004 2004年06月
• Climate regime shift in the North Pacific.  [招待講演]

  Shoshiro Minobe

  Historical transition and its future of ocean marine ecosystem. 2003年12月
• Influence of decadal Arctic Oscillation on Japan (East) sea and Okhotsk sea.  [招待講演]

  Shoshiro Minobe

  P04 Arctic environment change (IAPSO, IAMAS, IAHS) 2003年07月
• Interannual to interdecadal variations in Hadley and Walker circulations.  [招待講演]

  Shoshiro Minobe

  The Hadley Circulation: Present, Past and Future. 2002年11月
• Atmospheric circulation changes in 1998/99 over the North Pacific.  [招待講演]

  Shoshiro Minobe

  PICES CCCC - GLOBEC Joint, Coupled biophysical processes, fisheries, and climate variability in coastal and oceanic ecosystems of the North Pacific. North Pacific Marine Science Organization (PICES) 11th Annual meeting, 2002年10月
• Decadal variability and large-scale air-sea interaction.  [招待講演]

  Minobe, S, T. Suga, T. Watanabe, Y. Tanimoto, K. Hanawa

  Symposium for “Recent Progress in Physical Oceanography in Japan", Oceanographic Soc. 2002年10月
• Wavelet analysis of Pacific Decadal Oscillation and North Atlantic Osillation.  [招待講演]

  Shoshiro Minobe

  workshop Camp-GLOBEC 2002年02月
• Co-variability between the Pacific pentadecadal oscillation and length of day.  [招待講演]

  Shoshiro Minobe

  Symposium for Arctic Environmental Changes 2001年03月
• Interdecadal SST and SLP variability in the North Pacific  [招待講演]

  Minobe, S, T. Manabe, A. Shouji

  International workshop on “Preparation, processing and use of historical marine meteorological data” 2000年11月
• Pacific pentadecadal oscillation: its nature and impact.  [招待講演]

  Shoshiro Minobe

  “Interdecadal/interannual variability in the Pacific Ocean”, American Geophysical Union (AGU)/Western Pacific Geophysical Meeting (WPGM) 2000年06月
• Spatio-temporal structure of the pentadecadal and bidecadal variability over the North Pacific.  [招待講演]

  Shoshiro Minobe

  "The nature and impacts of North Pacific climate regime shifts (Science board symposium), North Pacific Marine Science Organization (PICES) 8th Annual meeting, 1999年10月
• “Resonance in bidecadal and pentadecadal climate oscillations over the North Pacific : Role in climatic regime shifts “  [招待講演]

  Shoshiro Minobe

  The workshop on “The development of the next-generation climate models.” 1999年03月
• ”Bidecadal and pentadecadal Oscillations over the North Pacific ”,  [招待講演]

  Shoshiro Minobe

  TRIANGLE ’98 1998年09月
• Bidecadal and pentadecadal climatic oscillations over the North Pacific and North America.  [招待講演]

  Shoshiro Minobe

  Hawaiian Winter Workshop on "Biotic impacts of extratropical climate change in the Pacific", 1998年01月
• Bidecadal and pentadecadal climatic oscillations over the North Pacific and North America.  [招待講演]

  Shoshiro Minobe

  IAMAS/IAPSO joint symposium JPM3 "Decadal and interdecadal variations in the Pacific", IAMAS/IAPSO Joint Assembly 1997年07月
• “ Interdecadal Climatic Variability over the North Pacific “  [招待講演]

  Shoshiro Minobe

  International Arctic Research Center, Science Plan Symposium 1997年
• A 50-70 year climatic oscillation over the North Pacific and North America.  [招待講演]

  Shoshiro Minobe

  Science board symposium, North Pacific Marine Science Organization (PICES), 5th Annual meeting, 1996年10月

その他活動・業績

• 南岸低気圧と総観スケール環境場 (南岸低気圧による大雪(2)マルチスケールの要因) -- (大雪の背景場 : 大気循環場と南岸低気圧)

  荒木 健太郎, 吉田 聡, 北畠 尚子, 加藤 輝之, 中村 啓彦, 早崎 将光, 見延 庄士郎, 渡邉 俊一, 新野 宏, 上野 健一, 安藤 直貴 気象研究ノート (240) 163 -234 2019年12月
• 気候系のHotspot:中緯度の暖流や水温前線が及ぼす気候系への影響

  中村尚, 中村尚, 磯辺篤彦, 立花義裕, 早坂忠裕, 川村隆一, 野中正見, 川合義美, 見延庄士郎, 三寺史夫, 吉田聡 天気 66 (1) 32‐38 2019年01月31日 [査読無し][通常論文]
  
• 北西太平洋海面水温前線に対する大気応答実験

  吉田聡, 見延庄士郎 日本気象学会大会講演予稿集 (109) 271 2016年04月30日 [査読無し][通常論文]
  
• 梅雨期の東シナ海黒潮における大気海洋相互作用の船舶観測(その2)

  佐々木克徳, 森信行, 見延庄士郎, 中村啓彦, 仁科文子, 岩崎慎介, 磯辺篤彦 日本海洋学会大会講演要旨集 2016 2016年
• “Hot spots” in the climate system: New developments in the extratropical ocean-atmosphere interaction research

  Hisashi Nakamura, Atsuhiko Isobe, Shoshiro Minobe, Humio Mitsudera, Masami Nonaka, Toshio Suga Hot Spots in the Climate System: New Developments in the Extratropical Ocean-Atmosphere Interaction Research 1 -170 2016年01月01日 [査読無し][通常論文]
   

  This book consists of the articles from the special issue of “‘Hot Spots’ in the Climate System” in the Journal of Oceanography, Vol. 71 No. 5, 2015, comprising 9 chapters that cover a wide spectrum of topics. This spinoff book is a collection of papers on the scientific outcomes of a nationwide 5-year project funded by the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT) and known internationally as the “Hot-Spot Project.” The academic achievement of the project has gained international recognition, making substantial contribution to unveiling the climatic role of warm western boundary ocean currents, including the Kuroshio, and associated oceanic fronts characterized by sharp temperature gradients and active meso-scale oceanic eddies. Specifically, those warm currents may be called “hot spots” in the climate system, as they intensively release heat and moisture to the atmosphere, thereby acting to organize clouds and precipitation systems and set conditions favorable for recurrent development of storms. This spinoff is a unique collection of the outcome of the particular project. The collected papers cover a wide range of aspects of ocean-atmosphere interaction characteristic of the oceanic fronts and continental marginal seas, unveiled through observational, theoretical, analytical, and numerical investigations. Most of the readers of the book are assumed to be researchers and graduate students who study climate dynamics, physical oceanography, atmospheric science, and air-sea interaction.
• 東シナ海が梅雨前線帯に及ぼす影響

  久野木梓織, 万田敦昌, 児玉安正, 飯塚聡, 佐藤和敏, FATHRIO Ibnu, 三井拓, 瀬古弘, 茂木耕作, 見延庄士郎, 立花義裕 日本気象学会大会講演予稿集 (107) 345 2015年04月30日 [査読無し][通常論文]
  
• 素過程から数十年スケールに及ぶ海洋大気結合変動の解析研究(2013年度日本海洋学会賞受賞記念論文)

  見延 庄士郎, Shoshiro Minobe, 北海道大学大学院理学院自然史科学専攻, Department of natural history sciences Graduate School of Science Hokkaido University 海の研究 = Umi no Kenkyu (Oceanography in Japan) 23 (5) 147 -169 2014年09月15日 

  地球の2大流体圏である大気と海洋は,相互に影響を与え合っている。大気が海洋に与える影響は,強力かつ明瞭であるのに対して,海洋が大気に与える影響は未解明の部分が大きい。この報告では,熱帯太平洋の季節変動,北太平洋と周辺領域の十年スケール変動,そして中緯度の素過程研究の立場からの大気海洋相互作用について,いくつかの結果を紹介する。海洋が大気に与える影響を,特にデータ解析から明らかにするには,鍵となる特徴を解析することが有効である。熱帯太平洋の年周期変動では,大気海洋に共通する海洋の速度での伝播を,十年スケール変動では大気中の周期的な振動を,そして中緯度大気海洋相互作用では大気に海洋のスケールを見出すことをテコとしてきた。またこの論文では研究結果の紹介に加えて,その背後にある考えなどについても紹介する。Two major fluids of the earth are the ocean and the atmosphere, each of which influence the other. The influence of the atmosphere onto the ocean is strong and clear, while the opposing oceanic influence onto the atmosphere is not well understood. In this paper, several results of co-variability of the ocean and the atmosphere and interaction between them are introduced. Specific topics are seasonal variability over the tropical Pacific, decadal variability over and around the North Pacific, and mid-latitude air-sea interaction from a point of view of process-oriented studies. In order to identify oceanic impacts onto the atmosphere, especially using data analysis, it is useful to detect key features. Such key features are propagation signal commonly found in the atmosphere and the ocean with a speed of oceanic propagation for annual variability over the tropical Pacific, oscillation in the atmosphere for the decadal variability, and atmospheric signatures on oceanic spatial scales for the mid-latitude air-sea interactions. Some ideas behind the studies are also introduced.
• 九州西方の暖水域が梅雨前線帯に及ぼす影響

  久野木梓織, 万田敦昌, 児玉安正, 飯塚聡, 佐藤和敏, FATHRIO Ibnu, 三井拓, 若杉春彦, 瀬古弘, 茂木耕作, 川合義美, 見延庄士郎, 立花義裕 日本海洋学会大会講演要旨集 2014 47 2014年09月01日 [査読無し][通常論文]
  
• 梅雨期の東シナ海黒潮における大気‐海洋相互作用の船舶観測

  森信行, 見延庄士郎, 中村啓彦, 佐々木克徳, 仁科文子, 岩崎慎介, 磯辺篤彦 日本海洋学会大会講演要旨集 2014 27 2014年03月10日 [査読無し][通常論文]
  
• 冬季東シナ海黒潮前線上での大気海洋同時観測-2010,2012,2013年の比較-

  笠毛健生, 磯辺篤彦, 見延庄士郎, 万田敦昌, 岩崎慎介 日本海洋学会大会講演要旨集 2014 2014年
• 海洋学の10年展望(I)―日本海洋学会将来構想委員会物理サブグループの議論から―

  岡英太郎, 磯辺篤彦, 市川香, 升本順夫, 須賀利雄, 川合義美, 大島慶一郎, 島田浩二, 羽角博康, 見延庄士郎, 早稲田卓爾, 岩坂直人, 河宮未知生, 伊藤幸彦, 久保田雅久, 中野俊也, 日比谷紀之, 寄高博行 海の研究 22 (6) 191 -218 2013年11月15日 [査読無し][通常論文]
  
• 東シナ海黒潮上における風速強化―2012年5月の事例解析―

  万田敦昌, 若杉春彦, 濱野五月, 三井拓, 山内晃, 河本和明, 兼原壽生, 青島隆, 清水健一, 内田淳, 下田真子, 八木光晴, 佐藤和敏, 久野木梓織, 関真理子, 佐々木実紀, 和田幸恵, FATHRIO Ibnu, 児玉安正, 飯塚聡, 松本佳華, 井上晃介, 佐藤由布子, 佐藤尚毅, 丸山拓海, 齋藤雅典, 早坂忠裕, 日高拓哉, 松永拓也, 冨田智彦, 見延庄士郎, 茂木耕作, 川合義美, 安藤雄太, 鈴木はるか, 鈴木耕二郎, 谷口佳於里, 立花義裕 日本気象学会大会講演予稿集 (104) 327 2013年10月 [査読無し][通常論文]
  
• 東シナ海黒潮上における風速強化―2012年5月の事例解析―

  万田敦昌, 若杉春彦, 濱野五月, 三井拓, 山内晃, 河本和明, 兼原壽生, 青島隆, 清水健一, 内田淳, 下田真子, 八木光晴, 佐藤和敏, 久野木梓織, 関真理子, 佐々木実紀, 和田幸恵, FATHRIO Ibnu, 児玉安正, 飯塚聡, 松本佳華, 井上晃介, 佐藤由布子, 佐藤尚毅, 丸山拓海, 齋藤雅典, 早坂忠裕, 日高拓哉, 松永拓也, 冨田智彦, 見延庄士郎, 茂木耕作, 川合義美, 安藤雄太, 鈴木はるか, 鈴木耕二郎, 谷口佳於里, 立花義裕 日本海洋学会大会講演要旨集 2013 40 2013年08月 [査読無し][通常論文]
  
• D308 AFESを用いた北西太平洋海面水温前線に対する大気応答実験(中高緯度大気・相互作用,口頭発表)

  吉田 聡, 見延 庄士郎, 中村 尚 大会講演予講集 104 411 -411 2013年
• 2012: Ocean Science Meeting 2012報告

  見延庄士郎, 須賀利雄, 佐々木克徳, 安藤健太郎, 渡邉英嗣, 蒲生俊敬, 齊藤宏明, 池田元美, 鈴木亨 日本海洋海洋学会ニュースレター 2 (1) 3 -6 2012年05月 [査読無し][通常論文]
  
• 東シナ海・黒潮前線を横断するXBTとGPSゾンデの同時観測(2)

  笠毛健生, 磯辺篤彦, 見延庄士郎, 万田敦昌, 中村啓彦, 伊藤匡史, 緒方香都, 西川はつみ, 立花義裕, 加古真一郎 日本海洋学会大会講演要旨集 2011 71 2011年09月01日 [査読無し][通常論文]
  
• 東シナ海・黒潮前線を横断するXBTとGPSゾンデの同時観測

  笠毛健生, 磯辺篤彦, 見延庄士郎, 万田敦昌, 中村啓彦, 伊藤匡史, 緒方香都, 西川はつみ, 立花義裕, 加古真一郎 日本海洋学会大会講演要旨集 2011 18 2011年03月14日 [査読無し][通常論文]
  
• A103 湾流に対する大気応答の浅い加熱モードと深い加熱モード(II)(大気海洋相互作用,一般口頭発表)

  見延 庄士郎, 宮下 昌人, 吉田 聡, 時長 宏樹, 謝 尚平 大会講演予講集 97 40 -40 2010年04月30日 [査読無し][通常論文]
  
• A104 領域大気モデル中の境界層全層における湾流に対する大気応答のメカニズム(大気海洋相互作用,一般口頭発表)

  高玉 孝平, 見延 庄士郎, 稲津 將 大会講演予講集 97 41 -41 2010年
• D108 AFESにおけるメキシコ湾流SST勾配に対する降水応答(相互作用)

  吉田 聡, 見延 庄士郎, 謝 尚平 大会講演予講集 96 260 -260 2009年10月31日 [査読無し][通常論文]
  
• 「新しい地球学-太陽-地球-生命圏相互作用系の変動学-」, 渡邊誠一郎・檜山哲哉・安成哲三編, 名古屋大学出版会, 2008年3月, 341頁, 4800円(本体価格), ISBN978-4-8158-0590-6(本だな)

  見延 庄士郎 天気 56 (1) 41 -42 2009年01月31日 [査読無し][通常論文]
  
• D112 東シナ海の黒潮による梅雨への影響 : 降水集中化の可能性(相互作用)

  浅井 丈昭, 見延 庄士郎, 稲津 將 大会講演予講集 96 264 -264 2009年
• C213 湾流に対する大気応答の冬季モードと夏季モード(相互作用)

  見延 庄士郎, 宮下 昌人, 吉田 聡, 小守 信正, 謝 尚平 大会講演予講集 94 241 -241 2008年10月31日 [査読無し][通常論文]
  
• 北太平洋における気候の数十年スケール変動に関する研究 : 2006年度堀内賞受賞記念講演

  見延 庄士郎 天気 55 (3) 135 -147 2008年03月31日 [査読無し][通常論文]
  
• 第19回日本気象学会夏期特別セミナー(若手会夏の学校)の報告

  見延 庄士郎, 河村 公隆, 藤吉 康志, 長谷部 文雄, 近本 喜光 天気 55 (1) 55 -56 2008年01月31日 [査読無し][通常論文]
  
• オホーツク海の十年変動 : 海氷と上層水温

  佐々木 克徳, 見延 庄士郎 低温科学 65 21 -30 2007年03月23日 [査読無し][通常論文]
   

  オホーツク海の海氷と上層水温の十年変動についての時空間構造と、その大気との関係について解析を行った。冬季の海氷の十年変動はオホーツク海北部で大きい振幅を持ち、1980年代の初めから1990年代中頃までは減少傾向、それ以降は海氷増加の傾向を示す。この海氷変動は秋季の大気変動に強く影響されている。一方、オホーツク海南部の夏期(5-10月)の上層水温の十年変動はクリル海盆付近で大きい振幅を持ち、概ね十年毎に温暖のピークを持つ準十年変動を示す。この上層水温の十年変動はその前の冬季の大気変動に強く影響されている。
• Climate and marine birds and mammals in the North Pacific.

  Watanuki Y, Minobe S, Sydeman B PICES Press 15 18 -19 2007年 [査読無し][通常論文]
  
• P169 メキシコ湾流SST勾配に対する低気圧活動の応答

  吉田 聡, 小守 信正, 見延 庄士郎, 謝 尚平 大会講演予講集 90 327 -327 2006年09月30日 [査読無し][通常論文]
  
• P203 1999-2001年の黒潮親潮続流域における異常昇温の構造・メカニズム・インパクト(太平洋・インド洋域における大気海洋結合現象)

  浅川 尚吾, 見延 庄士郎, 佐々木 克徳 大会講演予講集 89 311 -311 2006年
• 南極海氷域における季節内海氷変動のモデル実験

  馬場賢治, 見延庄士郎, 木村詞明, 若土正暁 極域気水圏シンポジウムプログラム・講演要旨 27th 51 -52 2004年12月 [査読無し][通常論文]
  
• 南極海氷域における海氷と大気の季節内変動の関係について

  馬場賢治, 見延庄士郎, 木村詞明, 若土正暁 日本気象学会大会講演予稿集 85 (85) 305 -305 2004年05月16日 [査読無し][通常論文]
  
• 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 2003年11月05日
• 長期変動とレジーム・シフト (総特集 気候-海洋-海洋生態系のレジーム・シフト(上)実態とメカニズム解明へのアプローチ)

  見延 庄士郎 海洋 35 (2) 86 -94 2003年02月
• 降水の20年変動の全球分布 (総特集 北太平洋の十年変動--物理・化学・生物の接点を求めて)

  中野渡 拓也, 見廷 庄士郎 海洋 35 (1) 52 -58 2003年01月 [査読無し][通常論文]
  
• 降水量の20年変動の季節依存性

  中野渡 拓也, 見延 庄士郎 大会講演予講集 82 365 -365 2002年10月09日
• 南極海氷域の大気と海氷の変動

  馬場賢治, 若土正暁, 見延庄士郎 日本気象学会大会講演予稿集 81 (81) 380 -380 2002年05月 [査読無し][通常論文]
  
• 北太平洋の20年変動と全球降水量変動との関係

  中野渡 拓也, 見延 庄士郎 大会講演予講集 79 34 -34 2001年05月08日
• 同期した50年変動と20年変動がもたらす気候レジームシフト (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) -- (1章 太平洋・インド洋セクターにおける長期変動)

  見延 庄士郎 号外海洋 (24) 42 -49 2001年 [査読無し][通常論文]
  
• 第22回国際測地学地球物理学連合総会(IUGG99)報告(2)

  岩崎 俊樹, 久芳 奈遠美, 那須野 智江, 中田 隆, 円山 憲一, 竹見 哲也, 平沢 尚彦, 日暮 明子, 岡田 靖彦, 楠 昌司, 江守 正多, 羽角 博康, 榎本 剛, 谷貝 勇, 井上 孝洋, 沖 大幹, 谷本 陽一, 根田 昌典, 渡部 雅浩, 見延 庄士郎, 中村 尚, 大谷 竜, 川村 宏, 小池 俊雄, 井上 豊志郎, 可知 美佐子 天気 47 (2) 97 -107 2000年02月29日 [査読無し][通常論文]
  
• 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 2000年02月29日 [査読無し][通常論文]
  
• デジタル化されたKobe Collection : 歴史的海上気象資料のデジタル化がもたらす海洋・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 1999年08月05日 [査読無し][通常論文]
  
• デジタル化されたKobe Collection : 歴史的海上気象資料のデジタル化がもたらす海洋・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, 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 1999年08月05日
• 北太平洋・北米における20年変動と50年変動の空間・季節分布 (特集 気候のレジ-ム・シフトと海洋生態系)

  見廷 庄士郎 海洋 30 (7) 402 -411 1998年07月 [査読無し][通常論文]
  

受賞

• 2016年08月 内閣総理大臣 第９回海洋立国推進功労者表彰, 「海洋に関する顕著な功績」分野
   海洋と大気の物理的な相互作用の研究 

  受賞者: 見延庄士郎

共同研究・競争的資金等の研究課題

• 地球温暖化による海洋変化が日本・東アジアにもたらす海面上昇：メカニズムと将来予測

  文部科学省：科学研究費補助金(基盤研究(B))

  研究期間 : 2014年 -2017年 

  代表者 : 見延 庄士郎
• エクマンパンピング駆動モデル:熱帯海洋変動の原因解明における基盤概念と技術の創出

  文部科学省：科学研究費補助金(挑戦的萌芽研究)

  研究期間 : 2014年 -2016年 

  代表者 : 見延 庄士郎
• 大洋スケール大気海洋相互作用

  文部科学省：科学研究費補助金(新学術領域研究(研究領域提案型))

  研究期間 : 2010年 -2014年 

  代表者 : 見延 庄士郎, 稲津 將, 吉田 聡, 小守 信正

   

  データ解析では,A2-3班と連携し世界に先駆けて,雲の中まで調査することが可能な雲レーダーを搭載するCloudSAT衛星データを用いて大気海洋相互作用にともなう雲構造を同定する研究を開始した.また,北西太平洋のSSTの経年変動が最も大きい、亜熱帯循環と亜寒帯循環の境界のフロント付近において、SSTの変動と衛星データによる大気データ(:海上風、積算雲水量)との関係を調べ,海流変動がSST変動を通して大気場に影響を与えている可能性を示した。数値計算では,地球シミュレータ上の高解像度大気大循環モデルで北太平洋、または北大西洋上の海面水温勾配を平滑化した実験をそれぞれ10年分実施した。また、大気大循環モデル、大気海洋結合モデルでそれぞれ再現された梅雨前線の季節進行について解析を行い、対流圏中層ジェットと海面水温前線の相対位置によって変動する海洋から梅雨前線に供給される水蒸気量が梅雨明けに影響することを明らかにした。地球シミュレータ上の大気海洋結合モデルの出力に基づく大気海洋間の結合係数に関して解析を進め,その季節的・空間的な変動には,海洋フロント近傍での対流圏下層の局所的な安定度に加えて大規模な風系の変動が重要であることを見出した.非静力学領域・全球結合大気モデルにおいて,高解像度SSTによる駆動を可能とする開発を行った。1年分の予備的実験を2002年の海面水温を与えて行い、同モデルが計算機的に正常に終了するだけでなく、その結果が気候学的にも概ね観測と整合的であることを確認した。さらに,大洋規模の海洋フロントがどのように変動するかについて,これまで考えられていた大規模ロスビー波とは異なって,狭いジェットである黒潮続流や湾流に補足されるロスビー波が本質的であることを,高解像度海洋モデル出力結果にthin-jet理論を適用することで明らかにした.
• 高解像度解析・観測・階層モデルによる海洋前線への大気応答と海洋再応答の研究

  文部科学省：科学研究費補助金(基盤研究(A))

  研究期間 : 2010年 -2013年 

  代表者 : 見延 庄士郎, 稲津 將, 吉田 聡, 小守 信正, 磯辺 篤彦, 中村 啓彦, 万田 敦昌

   

  2011年6月に鹿児島大学・かごしま丸で梅雨期の東シナ海の黒潮横断観測を行った.同観測ではADCP(音響ドップラー流向流速計),XBT(投下式水温水深計),GPSゾンデを用い,72時間の観測時間内に黒潮上を3往復した.このように短期間に西岸境界流を3往復(6断面)して,大気応答を調べたのは世界初である.また,2010年12月に実施した東シナ海黒潮前線域における大気海洋観測で発見した従来の知見と異なる前線上における海上風の局所的な低下現象について,領域大気モデルを用いて,この海上風の弱化が,前線横断方向に風が吹き始める時期に限られた,一時的な現象であることを確認した。さらに,衛星風データであるASCATを用いて,上記の解析に使用するべく格子データセットを作成し,国際学術誌にて発表するとともに,インターネットを通してデータを無償配布している。数値計算では,地球シミュレータ上の高解像度大気大循環モデル実験から,東シナ海および日本南岸では海面水温勾配に対して大気下層は収束として応答し,日本東沖の黒潮親潮続流域では発散として応答していることを明らかにした。双方向ネスト大気モデルにおいて,東シナ海における黒潮が作り出す海面水温勾配が全球大気に及ぼす影響を調べる実験の準備を行った.また,梅雨期の黒潮に対する平均的な大気応答が,梅雨降水の黒潮上への集中をもたらすこと,および大気境界層を超え対流圏上層まで及ぶ影響を与えていることを,衛星および再解析データ解析,そして領域気象モデルを総合して明らかにした.この大気応答は,我々が2010年に提案したDeep heating modeと整合的であり,局所応答の強さは夏季のメキシコ湾流上と同程度であるが,大規模梅雨前線帯およびそれにともなう降水が加わることで,中緯度海流上の対流性降水としては世界で最も強いことが明らかとなった.
• pH・栄養塩・溶存酸素・クロロフィルにおける地球温暖化の影響評価:検出と要因特定

  文部科学省：科学研究費補助金(特定領域研究)

  研究期間 : 2009年 -2010年 

  代表者 : 見延 庄士郎

   

  前回の公募研究で作成した栄養塩・溶存酸素についての全球グリッド・データは,その基礎となる海洋観測データについてWorld Ocean Database 2005に収録されているものを用いていた.しかし,2009年に新しいWorld Ocean Database 2009が公開されたので,栄養塩・溶存酸素のグリッド・データをこれを用いて作り直した.また最も観測点数が多く,信頼できると考えられるリン酸について,日本の南方で顕著な減少トレンドとそれに重なっている十年スケールの変動について,水温・塩分場などと合わせて解析を行った.その結果,十年スケール変動は,黒潮大蛇行によって引き起こされていることが判明した.すなわち,大蛇行期には,栄養塩が顕著な増加を見せる.このような関係は,特に1960年代初め,そして1970年代後半の長期間持続した大蛇行に伴う栄養塩増加として表れていた.一方,大蛇行期間を除いてトレンドの有意性検定を行っても有意な減少トレンドが見られることから,リン酸塩の減少トレンドは黒潮大蛇行とは基本的に無関係であると結論でき,地球温暖化など他の要因の影響が考えられる.この減少トレンドは,その振幅極大が水深100m付近に見られ,地球温暖化と関係して表層の栄養塩減少メカニズムとして広く受け入れられている仮説である,成層強化による上下混合の抑制では説明し難い.もし,混合抑制であれば100mに減少トレンドの極大が生じるのではなく,それよりも浅い層でより強い栄養塩の減少が見られるはずである.この栄養塩の減少トレンドのメカニズムを理解することは,日本付近の栄養塩分布がそしてそれが影響する海洋生態系が今後どのように変化していくかを議論する上で非常に重要であろう.
• 海洋フロント域における大気海洋相互作用のマルチ時間スケール

  文部科学省：科学研究費補助金(基盤研究(B))

  研究期間 : 2007年 -2009年 

  代表者 : 見延 庄士郎, 小守 信正, 吉田 聡, 中村 知裕

   

  メキシコ湾流が,大気下層の境界層を超えて自由大気に与える一連の影響を発見し,この成果はNature2008年3月13日号の表紙を飾った.さらに,大気応答で夏に顕著な「深い加熱モード」と冬季に顕著な「浅い加熱モード」を発見し,圧力調整応答の観測的な証拠を得,夏季と冬季の大気の安定度の相違が大気応答の季節依存性に大きく影響していることを見出し,長期の大気海洋結合大循環モデル積分で衛星風観測と整合的な結果を得た.また,表面水温低下を引き起こす,潮汐による砕波の観測的な証拠を初めて得た.
• 酸素・栄養塩・PHの全球海洋変動解析

  文部科学省：科学研究費補助金(特定領域研究)

  研究期間 : 2007年 -2008年 

  代表者 : 見延 庄士郎

   

  栄養塩・溶存酸素についての全球グリッドデータを作成した. 格子間隔は水平1度で深度1000mまでの18層, 時間解像度は月毎であり, 1930年より現在までの期間をカバーしている-グリッド化の手法はガウス関数によるスムージングである. このグリッドデータセットは栄養塩については初めての, また溶存酸素についても先行研究以上の範囲をカバーするものであり, このデータセット作成の意義は大きいと言えよう. 本データセットは, 観測がない場合は欠損として扱っているが, 日本付近は世界でも最も欠損が少ない領域となり, 本データセットは世界で最も充実している日本付近の栄養塩・溶存酸素観測を, 簡単に解析することを可能とするものである. このデータセットを用いて, 地球温暖化によって生ずる可能性があるトレンド成分を同定したところ, 日本の付近に顕著な栄養塩の減少トレンドが生じていることが見出された.またpHについては, 元データとして用いているWorld Ocean Database 05のデータの信頼性が不十分であることが明らかになった. すなわち, 同データベースにはpH測定に関するスケール情報と, 基準水温情報がほとんど示されていない. 測定スケールの大部分はNBSスケールであることが期待されるが, 基準水温については現場水温か25Cあるいは他の水温であるかでpHの値が大きく異なり, この基準を統一する形でWorld Ocean Database 05のデータを解析することは不可能である. そこで, JODCで公開されている気象庁のpHデータを解析した. その結果, 一般に予想されているpH低下と, 大きな矛盾のない結果が得られた.
• 海洋の記憶の定量的評価

  文部科学省：科学研究費補助金(萌芽研究)

  研究期間 : 2007年 -2007年 

  代表者 : 見延 庄士郎
• 太平洋における1998/99年の気候レジーム・シフトの実態と機構の解明

  文部科学省：科学研究費補助金(基盤研究(C))

  研究期間 : 2003年 -2006年 

  代表者 : 見延 庄士郎

   

  1998/99年に生じた北太平洋全体におよぶ気候変化,およびその背景となる大気海洋の変動について研究を行った.ここでは特に主要な成果について報告する.データー解析から20年変動と50-70年変動とが周期比3対1で同期して,北太平洋の気候レジーム・シフトを引き起こしていることを代表者は提案していた.この理論的な背景を探るために,簡単な遅延振動子モデルに周期的な外力あるいは周期的な変調を加えて,同期が生じる理由と条件とを,従来よりもはるかに見通しよく説明した.1998/99年頃に太平洋周辺の海氷変動にも,大きな変化が生じていたことを見出した.ベーリング海の海氷では,春の海氷が1999年頃から東部ベーリング海で顕著に減少し,この変化はアラスカにおける低気圧偏差によることが明らかになった.また,オホーツク海の海氷は長期的に減少傾向が続いていたが,1990年代後半および2000年代前半には一転して海氷が多い状態となった.この長期変動には,秋季の大気の状態が重要であることを明らかにした.海洋表面水温変動の振幅が大きいフロント域において,1998/99年の変化がどういった特徴を持っているのかを,独自の高解像度SST格子データ(インターネットで公開済み)を作成し評価した.北太平洋の亜熱帯フロントでは,顕著な水温上昇が見られるものの,亜寒帯フロントでは特段の変化が見られなかった.このことは,1970年代のシフトでは亜寒帯フロントの方が明瞭な変化を示したことと対照的な結果である.また,レジーム・シフトを特徴づけるアリューシャン低気圧の変動は,その冬季の強度から線形トレンドを除くと,bimodalな分布を示し,非線形フィードバックがレジーム・シフトの背景として重要であることを示唆した.
• 北西太平洋における数十年変動に対する高解像度データ解析と数値実験

  文部科学省：科学研究費補助金(奨励研究(A))

  研究期間 : 1998年 -1999年 

  代表者 : 見延 庄士郎

   

  北太平洋西部の戦前において、観測手法の変遷によるバイアスが無視できないバケツまたはエンジン採水による従来の海面水温のグリッドデータの精度を、そのようなバイアスが無い採水ビンおよびBTデータに基づく海面水温のグリッドデータを作成して評価した。従来のグリッドデータの解像度は緯度経度5度であり、今回作成したデータは実効解像度が2〜3度(グリッドの間隔は0.5×0.5)である。この新たなデータによって、日本を中心とする1940年代のSSTの温度上昇の従来の推定は、過大評価であることが強く示唆された。このことは北太平洋の気候レジームシフトおよび温暖化研究において大きな意味を持ち、今後従来提案されているSSTの観測データの補正方法よりも高精度の補正方法を開発する上でその道を開くものである。また、既存データの解析から、北太平洋のレジームシフトは位相同期する50年変動と20年変動とが同期していることを明らかにした(Minobe 1999)。これらの50年変動と20年変動との同期は、北太平洋上の気圧とSSTおよびアラスカの地上気温に顕著に見られる。また50年変動は北太平洋および北極海上の冬季の経年変動の振幅変調をもたらしていることを報告した(Minobe and Mantua 1999)。数値実験ではわが国で初めてマイアミ大学等密度面座標海洋モデルを用いた研究を行い、1/3度の水平解像度で気候値に対する海洋応答を調査し、観測された風応力を与えて40年間の長期積分を行った。気候値に対する応答では、年周期のロスビー波がシャツキーライズ・ヘスライズなどの海嶺と相互作用し振幅が強化される様子を、初めて北太平洋の海洋大循環数値モデルで再現した。
• 北太平洋西部における数十年スケール変動のデータ解析

  文部科学省：科学研究費補助金(奨励研究(A))

  研究期間 : 1996年 -1996年 

  代表者 : 見延 庄士郎

   

  本研究は、50年から70年の周期を持つ変動が北太平洋および北米に存在することを、世界で初めて明らかにした。この長期変動は冬季・春季のアリューシャン低気圧の強化・弱化を伴い、アリューシャン低気圧が強い場合には、日本沿岸では親潮が通常よりも南下し、北米西部の春季気温は高いことが示された。これらの変動は、今世紀では1920年代・1940年代の気候シフトで特徴づけられるとともに、50-70年周期に統計的に有意なスペクトルピークを持つことが示された。このスペクトルの統計的な有意水準検定は、比較的あらたな手法であるMulti-Taper Methodを用いた。さらに、北米上で樹木年輪より推定される過去の気温データを解析することにより、50年〜70年スケールの変動は18世紀半ば以降継続していることが示された。この50〜70年スケール変動は親潮については顕著であるが、黒潮にはさほど影響が見られない。しかしながら、黒潮続流にも興味深い十年スケール変動が存在する。本研究では、1957年〜1992年の期間について黒潮続流の位置を144°E〜150°Eの区間で経度の関数として同定した。この区間の黒潮続流の平均緯度は1981年〜1987年の期間にその前後と比べて顕著な南下を示す。水温場の相関解析より黒潮続流の平均的な緯度の変動は、上流の黒潮流露および親潮第二分枝の勢力の強弱と関連することが示された。風応力分布との関連を解析した結果、黒潮続流の平均緯度は北太平洋上の風のcurlと弱い負の相関を持つことが判明した。一方、2つの定常蛇行の北向きの峰に当たる144°Eと150°Eの黒潮続流緯度の差は、本州東方の東西風応力と比較的高い相関を示す。黒潮続流の平均緯度と144°Eと150°Eの続流緯度の差が、異なる風応力分布パターンとの間で相関を持つことは、黒潮続流に関わるこれら二つの変動が異なるメカニズムによって定まることを示唆するものである。
• 日本海深層における数十年スケールの水温変動のGCM実験

  文部科学省：科学研究費補助金(奨励研究(A))

  研究期間 : 1995年 -1995年 

  代表者 : 見延 庄士郎, 身延 庄士郎

   

  日本海における深層水温の変動は、深層水の形成量の変動によって生じていると考えられる。そこで深層水形成の長期変動をGCMで再現する第一歩として、非静水圧3次元数値モデルを開発し、密度の圧力依存性およびコリオリ項の水平成分が、深層水形成にどのような役割を果たすのかを検討した。モデル領域は水平32km×32km・鉛直に2000mとし、水平方向には周期境界条件を適用した。モデルのグリッド幅は水平250m・鉛直100mである。初期値には0℃で一様な水温分布と2000mで0.01PSUの塩分差のある塩分成層を与え、半径800mの円内で800W/m2の熱フラックスで、海洋表面から200m深まで一様に冷却した。コリオリパラメータには緯度45°Nにおける値を設定した。この条件下で、コリオリ項の水平成分および密度の圧力依存性の各々を組み込む場合組込まない場合の、計4通りのケースについて96時間の積分を行った。その結果、1)密度の圧力依存性を考慮する場合のみ深層水が形成される。2)密度の圧力依存性とコリオリ項の水平成分を考慮する場合には、78時間で海底に達する強い対流が生ずる。3)密度の圧力依存性を考慮してもコリオリ項の水平成分を含めない場合には、強い対流が生ずる時間が(2)に比べて約6時間早くなり、また36時間で弱い対流が生ずる、という結果が得られた。これらの結果から日本海の深層水形成過程に関して、密度の圧力依存性が非常に重要であり、またコリオリ項の水平成分の有無は有意な差を与えると結論される。

教育活動情報

主要な担当授業

大学運営

学内役職歴

• 2017年4月1日 - 2019年3月31日 研究戦略室室員
• 2019年4月1日 - 2020年9月30日 研究戦略室室員
• 2017年4月1日 - 2019年3月31日 総長補佐
• 2019年4月1日 - 2020年9月30日 総長補佐

委員歴

• 2013年 - 2017年   CLIVAR   Co-Chair Climate Dynamics Panel   http://www.clivar.org/clivar-panels/climate-dynamics
• 2015年 - 2016年   PICES   member, Study Group: Climate and Ecosystem Predictability   http://meetings.pices.int/members/study-groups/SG-CEP
• 2011年 - 2015年   The North Pacific Marine Science Organization   Co-chair of working group, North Pacific Climate Variability and Change
• 2007年 - 2008年   North Pacific Marine Science Organization   Science plan writing team member
• 2006年 - 2008年   アメリカ気象学会   Associate Editor, Journal of Climate   アメリカ気象学会
• 2002年 - 2006年   日本気象学会   編集委員Journal of the meteorological society of Japan   日本気象学会

メディア報道

• ”気候変化と変動”

  報道 : 2014年02月01日

  番組・新聞雑誌 : 環境・自然を考える会
• “空に映る海流：海洋から大気へのフィードバック”

  報道 : 2012年11月20日

  発行元・放送局 : 札幌新川高校
• “山の中での海洋物理学講座Final ～数値解析でひもとく気候変動のメカニズム～”

  報道 : 2010年08月05日

  発行元・放送局 : (独)科学技術振興機構・サイエンス・パートナーシップ・プロジェクト事業，秋田県立横手高校, 秋田・札幌
• “山の中での海洋物理学講座 ～数値解析でひもとく気候変動のメカニズム～”

  報道 : 2009年08月06日

  発行元・放送局 : (独)科学技術振興機構・サイエンス・パートナーシップ・プロジェクト事業，秋田県立横手高校， 秋田・札幌
• “空に映る海流：海洋から大気へのフィードバック”

  報道 : 2008年11月07日

  番組・新聞雑誌 : 第1７回先端科学移動大学2008
• “山の中での海洋物理学講座”

  報道 : 2008年08月05日

  発行元・放送局 : (独)科学技術振興機構・サイエンス・パートナーシップ・プロジェクト事業，秋田県立横手高校, 秋田・札幌
• “気候変動の科学 エルニーニョ”

  報道 : 2004年09月

  番組・新聞雑誌 : スーパーサイエンスハイスクール・札幌北校出前授業
• “十年から百年スケールの気候変動”

  報道 : 2004年04月

  発行元・放送局 : 21世紀COE「新・自然史科学創成」総合博物館・市民セミナー
• “気候変動と海 －太平洋で起こっていること：エルニーニョやその他の現象について－”

  報道 : 2003年07月

  番組・新聞雑誌 : 2003進学わくわくライブ札幌
• “気候変動と海 ―太平洋はなにをしているか―”

  報道 : 2002年10月

  番組・新聞雑誌 : リクルート進学ナビ
• “気候の長期変動と水産資源への影響”

  報道 : 2002年07月19日

  番組・新聞雑誌 : 水産油脂協会年次講演会