Influence of intraseasonal oscillations in the tropical atmosphere on extreme precipitation events over the Indochina Peninsular

2015 Fiscal Year Final Research Report

• Project/Area Number: 24510264
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Natural disaster science
• Research Institution: Japan Agency for Marine-Earth Science and Technology
• Principal Investigator: WU Peiming 国立研究開発法人海洋研究開発機構, 大気海洋相互作用研究分野, 主任研究員 (00360751)
• Co-Investigator(Kenkyū-buntansha): FUKUTOMI Yoshiki 国立研究開発法人海洋研究開発機構, シームレス環境予測研究分野, 特任研究員 (30392963)
• Project Period (FY): 2012-04-01 – 2016-03-31
• Keywords: 豪雨 / 赤道域季節内変動（MJO） / インドシナ半島 / 熱帯擾乱 / アジアモンスーン

Outline of Final Research Achievements

This study examined the influence of intraseasonal oscillations in the tropical atmosphere on extreme precipitation events over the Indochina Peninsular using observation data and the Japan Meteorological Agency Climate Data Assimilation System (JCDAS) re-analysis data. The results showed that westward-propagating tropical disturbances are the main causes of heavy rain in the region. In an active phase of the Madden Julian Oscillation (MJO), lower tropospheric barotropic dynamics can provide a significant source of kinetic energy for the growth and sustenance of tropical disturbances, causing widespread heavy rain. Eastward propagation of an active phase of the MJO from the Indian Ocean affected extreme precipitation events by providing conditions that are conducive to the growth and maintenance of tropical disturbances. The results of this study suggest that an active phase of the MJO plays an important role in formation of extreme precipitation events in the Indochina Peninsular.

Free Research Field

Meteorology