日本地球惑星科学連合2019年大会

講演情報

[J] ポスター発表

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] 熱帯インド洋・太平洋におけるマルチスケール大気海洋相互作用

2019年5月28日(火) 15:30 〜 17:00 ポスター会場 (幕張メッセ国際展示場 8ホール)

コンビーナ:清木 亜矢子(海洋研究開発機構)、東塚 知己(東京大学大学院理学系研究科地球惑星科学専攻)、名倉 元樹((独) 海洋研究開発機構)、釜江 陽一(筑波大学生命環境系)

[ACG38-P02] 日本の局所的な豪雨事例に対する熱帯太平洋の海面水温の影響

*今田 由紀子1川瀬 宏明1渡部 雅浩2高薮 出1 (1.気象庁気象研究所、2.東京大学大気海洋研究所)

キーワード:豪雨、大気大循環モデル、領域気候モデル

To detect the impact of global-scale climate on regional extreme events is challenging especially for disastrous regional heavy rainfall events which are often strongly affected by local topography. Observed records are too short to obtain significant concurrent signals. General circulation models (GCMs) can represent background large-scale circulations causing regional heavy rainfall but cannot resolve the topography. On the other hand, high-resolution regional climate model can resolve orographic rainfall but cannot provide the information of key processes in larger-scale circulation. Here, we prepared a large-ensemble pair of GCM and nonhydrostatic regional model simulations covering 6800-year samples. It enables us to access local rainfall event directly and investigate cause-to-effect pathway to explain the impact of global scale climate. As an example, we cite 2-type heavy rainfall events around precipitous terrains in Japan: western Kyushu type and eastern Kyushu type. The western Kyushu type related to moisture transport is attributed to the development of the Pacific subtropical High which is often forced by an El Nino event during previous winter. On the other hand, the eastern Kyushu type is attributed to TC approach which correlates to the central Pacific El Ninos. Through this new flamework with large-ensemble pairs of global and regional simulations, we can verify various influence pathways of large-scale climate to specific regional extreme events.