Papers 【 display / non-display 】

Papers 【 display / non-display 】

• Two-Dimensional Idealized Hadley Circulation Simulation for Global High Resolution Model Development

  Ryuji Yoshida, Takanobu Yamaguchi, Graham Feingold

  Journal of Advaces in Modeling Earth Systems   14 ( 1 )   2022  [Reviewed]

  DOI

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  Language：English   Publishing type：Research paper (scientific journal)   Joint Work  

• How Significant are Low-Level Flow Patterns in Tropical Cyclone Genesis over the Western North Pacific?

  Yoshida Ryuji, Fudeyasu Hironori

  MONTHLY WEATHER REVIEW   148 ( 2 )   559 - 576   2020.2  [Reviewed]

  DOI Web of Science CiNii Research

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  Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：American Meteorological Society   Joint Work  

  The low-level flow pattern characteristics of the tropical cyclone genesis (TCG) environment over the western North Pacific (WNP) were investigated not only for the periods during which TCG occurred, but also for the periods during which no TCG occurred. The flow patterns investigated were the shear line (SL), confluence region (CR), and easterly wave (EW) patterns. Although these flow patterns are recognized as favorable environmental conditions for TCG, their general characteristics, such as the climatological horizontal distribution, have not been previously investigated and there has been no comparison of the significance of the TCG cases to the climatological mean. We examined flow patterns using flow pattern indices defined by the modified semiobjective analysis method. SL and CR were broadly distributed over the WNP east of the Philippines during the boreal summer season. There was a peak in the EW from summer to autumn and it was distributed in a band running in an east–west direction at a lower latitude. Flow pattern indices of all three flow patterns gradually intensified until the TCG date was reached. The SL and EW indices became more intense compared to the climatological mean one day before the TCG, while that of the CR did not exceed the climatological mean. TCG occurred at the eastern edge of the area with a high genesis potential index and relative humidity and a weak vertical shear over flow patterns. This determination of the general characteristics of favorable flow pattern conditions improves our understanding of the TCG process.

• DCMIP2016: the tropical cyclone test case

  Willson, J. L. and Reed, K. A. and Jablonowski, C. and Kent, J. and Lauritzen, P. H. and Nair, R. a … Show more authors

  Geoscientific Model Development   17 ( 7 )   2493 - 2507   2024.2  [Reviewed]

  DOI Web of Science

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  Language：English   Publishing type：Research paper (scientific journal)   Joint Work  

  Other Link： https://gmd.copernicus.org/articles/17/2493/2024/

• Shallow Coastal Water Responses During the Near Landfall Intensification of Tropical Cyclones in the South China Sea

  Xiang Chunyi, Fudeyasu Hironori, Shimada Udai, Yoshida Ryuji

  Scientific Online Letters on the Atmosphere   20 ( 0 )   55 - 61   2024.1  [Reviewed]

  DOI Web of Science CiNii Research

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  Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：公益社団法人 日本気象学会   Joint Work  

  <p>Shallow coastal seawater response during the passage of near-landfall intensification (NLI) tropical cyclones (TCs) and non-NLI TCs was examined using oceanic and atmospheric reanalysis data and observations. The sea surface temperature ahead of the NLI-TC track is maintained or even increases when NLI-TC is approaching the land. The magnitude of the wind stress, which plays an important role in the NLI process, is related to the zonal surface wind on the right side of the tracks. Coastal mixed layer warming can be explained by Ekman transport under sustained wind stress due to surface wind forcing. The successive deepening of the coastal ocean boundary layer and the increase in warming in the subsurface seawater temperature by an average of 0.3°C, could maintain thermal capacity in a certain degree. This shallow coastal water response could partly explain the NLI progress in the northern South China Sea, indicating the importance of coastal ocean dynamics and air-sea interactions.</p>

• Contributions of the Large-Scale Environment to the Typhoon Genesis of Faxai (2019)

  FUDEYASU Hironori, SHIMADA Udai, OIKAWA Yoshinori, EITO Hisaki, WADA Akiyoshi, YOSHIDA Ryuji, HORIN … Show more authors

  Journal of the Meteorological Society of Japan. Ser. II   advpub ( 0 )   617 - 630   2022  [Reviewed]

  DOI Web of Science CiNii Research

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  Language：English   Publishing type：Research paper (scientific journal)   Publisher：Meteorological Society of Japan   Joint Work  

  <p>This study investigated the atmospheric and oceanic contributions to the genesis of Typhoon Faxai in 2019. Our statistical analysis using the tropical cyclone genesis score (TGS) attributed the tropical disturbance that developed into Faxai (Pre-Faxai) to easterly waves (EWs). The EW score evaluated by a grid version of the TGS (Grid-EW) averaged around the occurrence of Pre-Faxai was approximately twice as large as the climatological mean, and it was the second largest value in the past 38 years. The Pre-Faxai area with high Grid-EW scores could be traced back to the eastern North Pacific (ENP) around August 25, 2019. The lower-troposphere environment characterized by high Grid-EW scores was favorable for vortex formation because it provided a containment area for moisture entrained by the developing circulation or lofted by the deep convection therein. The Pre-Faxai area with high Grid-EW scores moved westward due to the background easterly flow over the ENP and then entered the western North Pacific (WNP). The Typhoon Intensity Forecast Scheme (TIFS) showed that the important environments for its genesis were ocean conditions and the vertical wind shear. The oceanic conditions contributed to the development of Pre-Faxai as it traveled over the WNP. The enhancement of vertical wind shear and subsequent suppression of the development of Pre-Faxai were caused by the lower-troposphere easterly winds associated with high EW scores. They were also caused by upper-troposphere westerly winds associated with an upper cold low northwest of Pre-Faxai. When the vertical shear decreased with weakening of the upper cold low, Pre-Faxai reached tropical storm intensity on September 4. Therefore, TGS and TIFS detected Pre-Faxai 10 days before the typhoon arose, which indicates that monitoring environmental factors such as EW and vertical wind shear are important for disaster prevention.</p>

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Review Papers 【 display / non-display 】

Review Papers 【 display / non-display 】

• 第 6 回非静力学モデルに関する国際ワークショップ(第25回非静力学モデルに関するワークショップ)の報告

  佐藤陽祐, 稲津將, 南出将志, 柳瀬友朗, 近藤誠, 大塚成徳, 吉田龍二, 佐藤拓人, 宮本佳明, 藤 原泰, 末木健太, 高須賀大輔, 伊藤純至, 橋本明弘, 八代尚

  天気   71 ( 2 )   75 - 81   2024.2

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  Language：Japanese   Publishing type：Rapid communication, short report, research note, etc. (bulletin of university, research institution)   Joint Work  

Awards 【 display / non-display 】

Awards 【 display / non-display 】

• 優秀研究者賞

  2024.3   横浜国立大学   奨励賞

  Individual or group name of awards：吉田龍二

• 外部資金表彰

  2023.10   横浜国立大学   表彰

  Individual or group name of awards：吉田龍二

Grant-in-Aid for Scientific Research 【 display / non-display 】

Grant-in-Aid for Scientific Research 【 display / non-display 】

• 最先端の観測技術と数値実験の融合で明らかにする雷雲の内部構造

  Grant number：24934544  2024 - 2028

  文部科学省  科学研究費助成事業  Grant-in-Aid for Scientific Research(A)

  Investigator(s)：佐藤　陽祐

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  Authorship：Coinvestigator(s)  Grant type：Competitive

Other external funds procured 【 display / non-display 】

Other external funds procured 【 display / non-display 】

• 室内実験によるMicrophysicsスキームの精緻化

  Grant number：JPMJMS2282-04  2022 - 2025

  Japan Science and Technology Agency  JST委託研究「ムーンショット型研究開発事業

  Investigator(s)：吉田龍二（横浜国立大学）

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  Authorship：Coinvestigator(s) 

  雲の生成・消滅をつかさどる雲微物理過程（Microphysics）は、台風の数値シミュレーションにおいて重要な役割を担う。本研究課題は、室内実験の実権データをベースに現存のMicrophysicsスキームの精緻化・改良によって、数値モデルの湿潤過程の表現性を改善させ、台風の理解・予測・制御に関連する数値シミュレーションの高度化を目指すものである。

Presentations 【 display / non-display 】

Presentations 【 display / non-display 】

• Development of a seeding method for the typhoon weakening based on the laboratory and the numerical simulation experiments

  Ryuji Yoshida (YNU), Hironori Fudeyasu (YNU), Masataka Murakami (YNU), Yuto Kitano (YNU), Yuki Kudo (YNU), Narihiro Orikasa (MRI/JMA), Takuya Tajiri (MRI/JMA), Ayumi Iwata (MRI/JMA), Mizuo Kajino (MRI/JMA), Yoshiaki Miyamoto (Keio Univ.), Tomoki Kajikawa (Tsukuba Univ.), Shogo Saruta (Tsukuba Univ.), Shoichi Akami (Tsukuba Univ.)

  AGU 2023 Fall Meeting  2023.12 

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  Event date： 2023.12

  Language：English   Presentation type：Poster presentation  

  Venue：サンフランシスコ市  

• 高解像度数値モデルの開発プラットフォームとしての理想化ハドレー循環シミュレーション

  吉田龍二 (横浜国立大学), Takanobu Yamaguchi (NOAA/CIRES UCB), Graham Feingold (NOAA)

  日本気象学会2022年秋季大会  2022.10 

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  Event date： 2022.10

  Language：Japanese   Presentation type：Oral presentation (general)  

  Venue：北海道大学  

• Development of a method for the typhoon weakening based on the chamber and the numerical simulation experiments

  Ryuji Yoshida (YNU), Hironori Fudeyasu (YNU), Masataka Murakami (YNU), Yuto Kitano (YNU), Yuki Kudo (YNU), Narihiro Orikasa (MRI/JMA), Takuya Tajiri (MRI/JMA), Ayumi Iwata (MRI/JMA), Mizuo Kajino (MRI/JMA), Yoshiaki Miyamoto (Keio Univ.), Tomoki Kajikawa (Tsukuba Univ.), Shogo Saruta (Tsukuba Univ.), Shoichi Akami (Tsukuba Univ.)

  International Workshop of TRC  2023.11 

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  Event date： 2023.11

  Language：English   Presentation type：Oral presentation (general)  

  Venue：横浜市  

• 室内実験と数値実験に基づいたシーディングによる台風制御手法開発

  吉田龍二 (横国大), 筆保弘徳 (横国大), 村上正隆 (横国大), 北野湧斗 (横国大), 折笠成宏 (気象研), 田尻拓也 (気象研), 岩田歩 (気象研), 梶野瑞王 (気象研), 宮本佳明(慶応大), 梶川友貴 (筑波大), 去田尚悟 (筑波大), 赤見彰一 (筑波大)

  2023年度 日本気象学会 秋季大会  2023.10 

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  Event date： 2023.10

  Language：Japanese   Presentation type：Oral presentation (general)  

  Venue：仙台市  

• Ideal numerical simulations for modification of tropical cyclone from the microphysical approach in the Typhoonshot-MS program.

  Ryuji Yoshida (YNU)

  The 6th International Workshop on Nonhydrostatic Models  2023.9 

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  Event date： 2023.8 - 2023.9

  Language：English   Presentation type：Oral presentation (general)  

  Venue：札幌市  

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Past of Collaboration and Commissioned Research 【 display / non-display 】

Past of Collaboration and Commissioned Research 【 display / non-display 】

• 富士通-横浜国大台風リサーチラボ

  Offer organization: 富士通株式会社   Cooperative Research within Japan  

  Project Year： 2022  -  2024 

Charge of on-campus class subject 【 display / non-display 】

Charge of on-campus class subject 【 display / non-display 】

• 2024   Climate Science Ⅱ

  Interfaculty Graduate School of Innovative and Practical Studies

• 2024   Climate Science Ⅰ

  Interfaculty Graduate School of Innovative and Practical Studies

• 2024   Climate ScienceⅡ

  Graduate School of Environment and Information Sciences

• 2024   Climate ScienceⅠ

  Graduate School of Environment and Information Sciences

• 2024   大気科学Ⅱ

  College of Urban Sciences

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Committee Memberships 【 display / non-display 】

Committee Memberships 【 display / non-display 】

• 日本気象学会 計算科学研究連絡会

  2022 

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  Committee type：Academic society 

Social Contribution(Extension lecture) 【 display / non-display 】

Social Contribution(Extension lecture) 【 display / non-display 】

• 気象予報士会 神奈川支部 合同例会 招待講演

  Role(s)： Commentator,　Lecturer

  気象予報士会 神奈川支部  気象予報士会 神奈川支部 合同例会  2024.3