Investigation of interactions between various scale phenomena in the Baiu frontal zone

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K03744
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 17020:Atmospheric and hydrospheric sciences-related
• Research Institution: Kyushu University
• Principal Investigator: Kawano Tetsuya 九州大学, 理学研究院, 助教 (30291511)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 梅雨前線帯 / スケール間相互作用 / 渦位

Outline of Final Research Achievements

To investigate interactions between various scale phenomena that exist in the Baiu frontal zone, I conducted an analysis using atmospheric reanalysis data, idealized numerical experiments, and numerical simulations with realistic conditions. I focused on the transportation of low-level water vapor in the torrential rainfall cases because the interactions may appear clearly in such cases. A mesoscale vortex associated with latent heat release from active cumulonimbus enhances the northward transportation of low-level water vapor in front of the vortex. As a result, a new mesoscale convective system occurred and developed there. In addition, the convective system modulates the ambient conditions and is maintained in the modulated environment.

Free Research Field

気象学

Academic Significance and Societal Importance of the Research Achievements

渦位(非断熱加熱によって生成・消滅する渦を表す物理量)を用いて，梅雨前線帯の多重スケール階層構造に存在するスケール間相互作用を調査した。水蒸気が豊富な梅雨前線帯において活発な積乱雲群に伴う潜熱加熱によってメソスケール渦が生成され，その低気圧性循環はメソスケール渦前面の南からの水蒸気輸送を強化する。その結果，別の場所に活発な積乱雲群が発生・発達し，新たな大雨域が形成されるというメカニズムが存在していることが示された。