Environmental Factors for the Development of Heavy Rainfall in the Eastern Part of Japan during Typhoon Hagibis (2019)

• Takemi Tetsuya

  Disaster Prevention Research Institute, Kyoto University

• Unuma Takashi

  Japan Meteorological Agency

抄録

This study investigated the environmental factors responsible for the development of heavy rainfall in eastern Japan during the passage of Typhoon Hagibis (2019) by using mesoscale gridded analysis data as well as observed data. Environmental indices for diagnosing stability and moisture conditions were examined. It was found that the whole troposphere is almost saturated and the column total water vapor content is extremely large. In the lower troposphere we identified layers of moist absolutely unstable states with the thickness deeper than 2 km. Such deep moist absolutely unstable layers as well as abundant moisture content and almost saturated troposphere set a high potential for convective development. Under these favorable environmental conditions, the fact that the heights of the absolutely unstable layers' bottom are comparable to the mountain elevations is considered to be favorable for topographic lifting of unstable, moist air, which will trigger and activate strong convection and hence heavy rainfall. In spite of a moderate amount of convective available potential energy and a nearly moist-adiabatic lapse rate, moist absolute instability, abundant moisture, and high humidity jointly play a key role to increase the potential for generating the present heavy rainfalls.

収録刊行物

• SOLA

  SOLA 16 (0), 30-36, 2020

  公益社団法人 日本気象学会

キーワード

• Atmospheric Science

詳細情報

• CRID: 1390002184876872704
• NII論文ID: 130007801483
• DOI: 10.2151/sola.2020-006
• ISSN: 13496476
• HANDLE: 2433/245863
• Web Site: https://www.jstage.jst.go.jp/article/sola/16/0/16_2020-006/_pdf
• 本文言語コード: en
• データソース種別:
  • JaLC
  • IRDB
  • Crossref
  • CiNii Articles
  • KAKEN
• 抄録ライセンスフラグ: 使用不可