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 A (大気水圏科学) » A-CG 大気海洋・環境科学複合領域・一般

[A-CG38] 衛星による地球環境観測

2022年5月23日(月) 09:00 〜 10:30 104 (幕張メッセ国際会議場)

コンビーナ:沖 理子(宇宙航空研究開発機構)、コンビーナ:本多 嘉明(千葉大学環境リモートセンシング研究センター)、高薮 縁(東京大学 大気海洋研究所)、コンビーナ:松永 恒雄(国立環境研究所地球環境研究センター/衛星観測センター)、座長:岡本 幸三(気象研究所)

10:15 〜 10:30

[ACG38-06] Assimilation of Sea Surface Wind by Synthetic Aperture Radar in Typhoon Cases

*幾田 泰酵1嶋田 宇大1 (1.気象庁気象研究所)

To improve the accuracy of typhoon forecasts, it is necessary to improve the accuracy of the initial condition in addition to the accuracy of the numerical weather forecast model. In this study, we investigate the impact of the accuracy of the sea surface wind in the initial conditions of the model on the typhoon forecast. An effective observation that can capture detailed sea surface winds around a typhoon is the satellite-borne synthetic aperture radar. In the typhoon case, we assimilated the sea surface wind speed observed by the synthetic aperture radar. The assimilation method used was the four-dimensional variational method using ASUCA-Var, which is operated by the Japan Meteorological Agency. Since the characteristics of observation change between strong and weak winds, the bias correction amount and the observation error variance depending on the wind speed were obtained and used in the assimilation. Additionally, the variational quality control with the Huber loss function was adopted to make effective use of the observed data in strong wind conditions. As a result of the assimilation experiment, the typhoon intensity and path were slightly improved and the wind speed prediction was improved. In my presentation, I would like to show the impact of assimilation on forecasting, including a comparison between simulations and GPM satellite observations.