日本地球惑星科学連合2022年大会

講演情報

[E] 口頭発表

セッション記号 M (領域外・複数領域) » M-GI 地球科学一般・情報地球科学

[M-GI29] Data assimilation: A fundamental approach in geosciences

2022年5月26日(木) 15:30 〜 17:00 104 (幕張メッセ国際会議場)

コンビーナ:中野 慎也(情報・システム研究機構 統計数理研究所)、コンビーナ:藤井 陽介(気象庁気象研究所)、三好 建正(理化学研究所)、コンビーナ:加納 将行(東北大学理学研究科)、座長:中野 慎也(情報・システム研究機構 統計数理研究所)、藤井 陽介(気象庁気象研究所)

15:45 〜 16:00

[MGI29-08] Control simulation experiment for a typhoon case with a global numerical weather prediction system

*寺崎 康児1,2三好 建正1,2,3 (1.理化学研究所計三好予測科学研究室、2.理化学研究所計算科学研究センター、3.理化学研究所 数理創造プログラム)

キーワード:データ同化、気象制御

The earth’s atmosphere is a nonlinear and chaotic system. A small difference in the initial condition makes forecast different due to the chaos, the characteristics known as the “butterfly effect”. The predictability has been improved by the development of the NWP model, data assimilation, and observations for a long time. However, severe weather such as typhoon and torrential rainfall is a threat for us. Weather modification has also been investigated, such as cloud seeding and rain enhancement. It distributes cloud condensation nuclei and enhances the cloud formation based on the microphysical processes. Alternatively, this study explores to control a typhoon by taking advantage of the chaotic dynamics.
The Observing System Simulation Experiment (OSSE) is a widely used approach in data assimilation research. We extend the OSSE to what we call the control simulation experiment (CSE) which changes the nature state to the desired direction by adding control signals determined by the ensemble forecasts. This study targets a typhoon, which generated over the Northwest Pacific and hit Japan. We perform CSEs to weaken the typhoon, i.e., making the central sea level pressure (SLP) higher. We apply the control only to the horizontal wind field at the first model vertical layer. Here, we limit the control signal only to reduce the kinetic energy because it would be difficult to increase kinetic energy in a real-world intervention. The CSE is found effective, i.e., we successfully weaken the typhoon when it reaches Japan. We will present the most recent results at the meeting.