Development of typhoon ensemble forecasting system based on the source inverse problem of potential vorticity

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H01431
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 22040:Hydroengineering-related
• Research Institution: Gifu University
• Principal Investigator: YOSHINO Jun 岐阜大学, 大学院工学研究科, 教授 (70377688)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 自然災害 / 気象学 / 水工水理学 / 防災 / 高潮 / 台風

Outline of Final Research Achievements

The information on predictability in forecasts of not only typhoon track but also storm surge and heavy rainfall should be improved to provide effective evacuation information. In this study, we created “variational data assimilation method” to estimate typhoon pressure and vorticity distributions in initial conditions of numerical prediction model and “vorticity singular vectors method” to estimate initial perturbations for ensemble predictions. In addition, we developed an ensemble forecasting system for typhoon external forces that can take into account uncertainties in the forecasts of storm surge and heavy rainfall associated with typhoons, based on our original high-resolution typhoon model.

Free Research Field

水工水理学

Academic Significance and Societal Importance of the Research Achievements

本研究により，進路のみならず高潮や大雨についても予報のばらつきを考慮に入れた情報提供が可能となった．例えば，「◯◯地方では，台風が東よりに進路を取った場合により高潮の危険性が高く，最悪のケースでは潮位偏差は3.5mとなり，潮位偏差3mを超える確率は30%となるでしょう」といったより避難への実効性のある予報文を出せるようになる．このような情報提供により，住民の災害に対する油断（正常性バイアス）と避難行動の遅れの回避に繋がり，台風常襲地帯の我が国における地域防災力の向上に貢献できると期待される．