Investigating the mechanisms using water isotopes ratio and improving the predictability through satellite data assimilation of heavy rainfall associated with atmospheric rivers

• Project/Area Number: 19J01337
• Research Category: Grant-in-Aid for JSPS Fellows
• Allocation Type: Single-year Grants
• Section: 国内
• Review Section: Basic Section 22040:Hydroengineering-related
• Research Institution: The University of Tokyo
• Principal Investigator: 取出 欣也 東京大学, 生産技術研究所, 特別研究員(CPD)
• Project Period (FY): 2019-04-25 – 2024-03-31
• Project Status: Completed (Fiscal Year 2022)
• Budget Amount: ¥11,700,000 (Direct Cost: ¥9,000,000、Indirect Cost: ¥2,700,000); Fiscal Year 2021: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2020: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2019: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000)
• Keywords: 水同位体 / データ同化 / Atmospheric River / Data assimilation / Water isotope

Outline of Research at the Start

Atmospheric River （AR; 大気の川）とは、大気において帯状に水蒸気を大量輸送し、川のように見える現象を指す。本研究は、ARの関わる豪雨の予測改善のために、ARの豪雨に果たす役割を水同位体比という指標に着目して明らかにすると共に、衛星から観測データを用いてARの予測位置精度を向上させることを目的とする。加えて、それらの成果を地域気象モデル内の水同位体比の豪雨中における循環の改善に適用し、さらなる豪雨予測の向上へと繋げる。

Outline of Annual Research Achievements

本研究課題では、大気における大規模水蒸気輸送に着目し、豪雨の予測改善に向けた研究を行った。水蒸気の中に含まれる重い水同位体に着目し、最新の衛星観測を用いて気象予測の改善を目指した。まず、理想実験において水同位体比を同化することで対流圏中層において風速、比湿、温度場が10％以上改善することを示した。次に、実際の観測データを同化するため、気象モデルとの間に存在する気候/短期予測バイアスの季節性や地域性について、現地観測も用いて詳しく明らかにした。次に、衛星観測からバイアスを取り除き、衛星の観測演算子をデータ同化システムに組み込むことで実際の観測を用いた同化実験を行い、水蒸気同位体比が大気場や降水量の予測改善に繋がることを示した。また、大気において帯状に水蒸気を大量輸送する大気の川に関しても、熱帯と中緯度のそれぞれの運動による影響を明らかにし、予測精度の改善の可能性を示した。

Research Progress Status

翌年度、交付申請を辞退するため、記入しない。

Strategy for Future Research Activity

翌年度、交付申請を辞退するため、記入しない。

Research Products

• [Int'l Joint Research] University of Washington(米国)
• [Int'l Joint Research] Karlsruhe Institute of Technology(ドイツ)
• [Int'l Joint Research] University of Washington(米国)
• [Int'l Joint Research] Karlsruhe Institute of Technology(ドイツ)
• [Int'l Joint Research] University of Washington(米国)
• [Int'l Joint Research] Karlsruhe Institute of Technology(ドイツ)
• [Int'l Joint Research] University of Washington/University of California Berkeley/University of California Davis(米国)
• [Int'l Joint Research] Karlsruhe Institute of Technology(ドイツ)
• [Journal Article] What Distinguishes MJO Events Associated with Atmospheric Rivers? (2022)
  • Author(s): Toride Kinya、Hakim Gregory J.
  • Journal Title: Journal of Climate Volume: 35 Issue: 18 Pages: 6135-6149
  • DOI: 10.1175/jcli-d-21-0493.1
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] HISTORICAL ATMOSPHERIC ANALYSIS BY WEATHER CATEGORY ASSIMILATION USING GAUSSIAN TRANSFORMATION (2022)
  • Author(s): WANG Xiaoxing、TORIDE Kinya、YOSHIMURA Kei
  • Journal Title: Journal of Japan Society of Civil Engineers, Ser. B1 (Hydraulic Engineering) Volume: 78 Issue: 2 Pages: I_691-I_696
  • DOI: 10.2208/jscejhe.78.2_I_691
  • ISSN: 2185-467X
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Influence of Low‐Frequency PNA Variability on MJO Teleconnections to North American Atmospheric River Activity (2021)
  • Author(s): Toride Kinya、Hakim Gregory J.
  • Journal Title: Geophysical Research Letters Volume: 48 Issue: 13 Pages: 1-10
  • DOI: 10.1029/2021gl094078
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Improving weather forecasting by assimilation of water vapor isotopes (2021)
  • Author(s): Tada Masataka、Yoshimura Kei、Toride Kinya
  • Journal Title: Scientific Reports Volume: 11 Issue: 1 Pages: 1-9
  • DOI: 10.1038/s41598-021-97476-0
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Potential of Mid‐tropospheric Water Vapor Isotopes to Improve Large‐Scale Circulation and Weather Predictability (2021)
  • Author(s): Toride Kinya、Yoshimura Kei、Tada Masataka、Diekmann Christopher、Ertl Benjamin、Khosrawi Farahnaz、Schneider Matthias
  • Journal Title: Geophysical Research Letters Volume: 48 Issue: 5
  • DOI: 10.1029/2020gl091698
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] Reconstruction of Daily Weather in the 1810s by Diary Data Assimilation (2022)
  • Author(s): Wang, X., K. Toride, K. Yoshimura
  • Organizer: AGU Fall Meeting
  • Int'l Joint Research
• [Presentation] FTS satellite observation mission for understanding chemical and dynamical processes in the upper atmosphere (2022)
  • Author(s): Eguchi, N., K. Walker, N. Saitoh, Y. Yoshida, K. Yoshimura, K. Toride, M. Fujiwara, Y. Kawatani, Y. Yamashita, R. Nassar, D. Jones, D. Plummer, K. Strong
  • Organizer: JpGU2022
  • Int'l Joint Research
• [Presentation] Historical atmospheric analysis by weather category assimilation using gaussian transformation (2022)
  • Author(s): Wang, X., K. Toride, K. Yoshimura
  • Organizer: 第67回水工学講演会
• [Presentation] Can the assimilation of IASI water isotopologue observations improve the quality of meteorological analyses fields? (2021)
  • Author(s): Khosrawi, F., K. Toride, K. Yoshimura, C. Diekmann, B. Ertl, F. Hase, M. Schneider
  • Organizer: EGU General Assembly 2021
  • Int'l Joint Research
• [Presentation] Historical weather reconstruction by weather information assimilation using Gaussian transformation (2021)
  • Author(s): Wang, X., K. Yoshimura, K. Toride
  • Organizer: JpGU2021
  • Int'l Joint Research
• [Presentation] Water vapour isotopologue observations from space and examples for their scientific potential (2021)
  • Author(s): Schneider, M., B. Ertl, C. Diekmann, F. Khosrawi, A. N. Rohling, F. Hase, H. Bosch, T. Trent, I. L. Thurnherr, H. Sodemann, K. Toride, K. Yoshimura
  • Organizer: ESA Water Vapour CCI User workshop
  • Int'l Joint Research
• [Presentation] Can the assimilation of IASI water isotopologue observations improve the quality of meteorological analyses fields? (2021)
  • Author(s): Khosrawi, F., K. Toride, K. Yoshimura, C. Diekmann, B. Ertl, F. Hase
  • Organizer: EUMETSAT Meteorological Satellite Conference 2021
  • Int'l Joint Research
• [Presentation] , Can the assimilation of IASI water isotopologue observations improve the quality of tropical diabatic heating? (2021)
  • Author(s): Khosrawi, F., K. Toride, K. Yoshimura, C. Diekmann, B. Ertl, F. Hase
  • Organizer: Water isotopes: From Weather to Climate
  • Int'l Joint Research
• [Presentation] 水蒸気同位体比データ同化による気象予測精度の改善 (2021)
  • Author(s): 芳村圭、多田真嵩、取出欣也
  • Organizer: 日本気象学会2021年度秋季大会
• [Presentation] Impact of water vapor isotopes observation on tropospheric atmospheric circulation (2021)
  • Author(s): Yoshimura, K., K. Toride, M. Tada
  • Organizer: AGU Fall Meeting
  • Int'l Joint Research
• [Presentation] Testing isotopologues as diabatic heating proxy for atmospheric data analyses (2020)
  • Author(s): Khosrawi, F., K. Toride, K. Yoshimura, C. Diekmann, B. Ertl, M. Schneider
  • Organizer: EGU General Assembly 2020
  • Int'l Joint Research
• [Presentation] The influence of the MJO diversity on midlatitude teleconnection patterns (2020)
  • Author(s): Toride, K., G. J. Hakim
  • Organizer: AGU Fall Meeting
  • Int'l Joint Research
• [Presentation] Historical Weather Reconstruction by Cloud Cover Data Assimilation with Gaussian Transformation (2020)
  • Author(s): Wang, X., K. Yoshimura, K. Toride
  • Organizer: AGU Fall Meeting
  • Int'l Joint Research
• [Presentation] The impacts of assimilating IASI water vapor isotope on weather forecasts (2019)
  • Author(s): Kinya Toride
  • Organizer: Water Isotopes and Climate Workshop
  • Int'l Joint Research
• [Presentation] Impacts of assimilating high-resolution IASI water vapor isotopic observations on weather forecasts (2019)
  • Author(s): Kinya Toride
  • Organizer: American Geophysical Union Fall Meeting
  • Int'l Joint Research
• [Funded Workshop] American Geophysical Union Fall Meeting (2019)
• [Funded Workshop] Water Isotopes and Climate Workshop (2019)