日本地球惑星科学連合2018年大会

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-AS01] 高性能スーパーコンピュータを用いた最新の大気科学

2018年5月20日(日) 10:45 〜 12:15 ポスター会場 (幕張メッセ国際展示場 7ホール)

コンビーナ:瀬古 弘(気象研究所)、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、共同)、三好 建正(理化学研究所計算科学研究機構)

[AAS01-P09] Numerical simulation of a heavy rain event in Hiroshima city on 19-20 August 2014

*大泉 伝1斉藤 和雄2Duc Le1伊藤 純至2 (1.国立研究開発法人海洋研究開発機構、2.気象研究所)

キーワード:豪雨、高解像度、数値予報

In Hiroshima, heavy rainfall caused debris flows on 19-20 August 2014. The heavy rain was a line-shaped rainband caused by “back-building formation” in a relatively narrow region. To predict and mitigate this kind of disaster, an accurate numerical prediction is necessary.

In this study, we investigated important factors in a numerical weather prediction (NWP) model that impact on a performance of heavy rainfall forecast. The investigated factors were grid spacings (5 km to 250 m), planetary boundary layer (PBL) schemes, model domain sizes, lateral boundary conditions in nesting simulations, and terrain representations.

Results indicated that ultra-high-resolution (500-250 m grid spacing) experiments showed better performance than coarser-resolution experiments (5 and 2 km grid spacing) in the rainfall cases. The differences of grid spacings had a larger impact on the position of rainband. These results demonstrate that the ultra-high-resolution NWP model has the possibility to improve predictions of heavy rainfall.