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-AS06] [EE] 台風研究の新展開~過去・現在・未来

2017年5月20日(土) 10:45 〜 12:15 ポスター会場 (国際展示場 7ホール)

コンビーナ:中野 満寿男(海洋研究開発機構)、和田 章義(気象研究所台風研究部)、金田 幸恵(名古屋大学宇宙地球環境研究所)、伊藤 耕介(琉球大学)

[AAS06-P10] Interannual variations of tropical cyclone frequency over South China Sea

*Xi Lu1 (1.Sun Yat-sen University)

キーワード:tropical cyclone , interannual change, South China Sea

This study attempts to investigate the interannual changes of tropical cyclone (TC) frequency over South China Sea (SCS) in the different seasons of summer (May-August) and winter (September-December) during 1977-2012. The spectral analysis indicate that during the summer, there is a periodicity of 4-8 years between 1993-2003 and an obvious interdecadal signal while during the winter the periodicity of 2-8 yeas is dominated between 1980 and 1992. The differences of characteristic between the summer and winter is related to the role of Indian Ocean. During the winter the subtropical Indian Ocean Dipole (IOD) around 20ºS induces a cyclone circulation over the North Indian Ocean that leads to a upper-level divergence and low-level cyclone with updraft over SCS that is favorable for TC formation. The impact of subtropical IOD becomes weaker during the summer, however the colder sea surface temperature still can be found in the western part of Indian Ocean. Meanwhile western North Pacific warm pool also results in an ascending flow over the SCS and enhances MJO activity there that increases the numbers of SCS TCs.