JpGU-AGU Joint Meeting 2017

講演情報

[EE] ポスター発表

セッション記号 A (大気水圏科学) » A-AS 大気科学・気象学・大気環境

[A-AS12] [EE] 高性能スーパーコンピュータを用いた最新の大気科学

2017年5月20日(土) 15:30 〜 17:00 ポスター会場 (国際展示場 7ホール)

コンビーナ:瀬古 弘(気象研究所)、三好 建正(理化学研究所計算科学研究機構)、小玉 知央(独立行政法人海洋研究開発機構)、滝川 雅之(独立行政法人海洋研究開発機構)

[AAS12-P06] Impacts of dense surface observations on predicting torrential rainfalls on September 9, 2015 around Tochigi and Ibaraki prefectures

*前島 康光1三好 建正1,2 (1.理化学研究所 計算科学研究機構、2.メリーランド大学 カレッジパーク)

キーワード:Data Assimilation, Surface weather observation

To investigate the impact of dense surface observations on a severe rainfall event occurred on September 9, 2015 around Tochigi and Ibaraki prefectures, we perform a series of data assimilation (DA) experiments using the Local Ensemble Transform Kalman Filter (LETKF) with the SCALE regional NWP model. In this event, an active rainband was maintained for an extended period and caused torrential rainfalls over 500 mm/day with catastrophic flooding.
Two DA experiments were performed: the control experiment (CTRL) at 4-km resolution with only conventional observations (NCEP PREPBUFR), and the other with additional every minute surface observation data (TEST). CTRL showed general agreement with the observed rainfall patterns, although the intensity was smaller, and rainfall area was shifted westward. By contrast, TEST showed stronger rainfall intensity, better matching with the observed precipitation. Dense surface DA contributed to improve the moisture field in the lower layer, leading to intensified rainfall amount. The results suggest that the dense surface DA have a potential to improve the forecast accuracy for severe rainfall events.