Multi-scale study of heavy rainfall formation
Grant-in-Aid for Scientific Research (A)
|Allocation Type||Single-year Grants |
Natural disaster science
|Research Institution||NAGOYA UNIVERSITY |
TAKEDA Takao Institute for Hydrospheric-Atmospheric Sciences, Professor, 大気水圏科学研究所, 教授 (60022604)
SAITO Kazuo Meteorological Research Institute, JMA,Researcher, 予報研究部, 主任研究官 (70391224)
GENG Biao Institute for Hydrospheric-Atmospheric Sciences, Assistant Professor, 大気水圏科学研究所, 助手 (10293721)
TSUBOKI Kazuhisa Institute for Hydrospheric-Atmospheric Sciences, Associate Professor, 大気水圏科学研究所, 助教授 (90222140)
NAKMURA Kenji Institute for Hydrospheric-Atmospheric Sciences, Professor, 大気水圏科学研究所, 教授 (20262917)
加藤 内蔵進 名古屋大学, 大気水圏科学研究所, 助手 (90191981)
藤吉 康志 北海道大学, 低温科学研究所, 教授 (40142749)
|Project Period (FY)
1996 – 1998
Completed (Fiscal Year 1998)
|Budget Amount *help
¥34,900,000 (Direct Cost: ¥34,900,000)
Fiscal Year 1998: ¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1997: ¥14,600,000 (Direct Cost: ¥14,600,000)
Fiscal Year 1996: ¥17,900,000 (Direct Cost: ¥17,900,000)
|Keywords||Baiu front / cloud cluster / cumulonimbus / orographic effect / rainband / Doppler radar / numerical model / satellite / 豪雨の形成 / メソβ帯状積乱雲群 / ドップラーレーダー観測 / 雲の組織化 / メソα雲群 / 集中豪雨 / ドップラーレーダ観測|
On the basis of the special observation, data analyses and numerical study which were performed in this three yeas, we synthesized processes of heavy rainfall formation and its predictability. Important results are summarized as follows.
(a) A significant two-year periodical variations were found in the distribution of cloud amount over the East Asia and rainfall over Japan Islands during the Baiu season.
(b) In a cloud cluster, with a horizontal scale of several hundred kilometer, which was long-lasting and stationary owing to successive formation of cumulonimbus group at its western edge, its precipitation efficiency was high.
(c) In the situation of the sufficiently moist lower troposphere, a transverse rainband was formed and moved slowly. A mountain range occasionally caused a long-lasting and stationary rainband.
(d) Complex behavior of precipitation cells and variation of environmental flow varied the middle level dry inflow and low level moist inflow. This resulted in a selective development of a convective cell and concentration of heavy rainfall.
(e) In a moist atmosphere, precipitation enhancement occurred in two stages in the upstream of an orography. According to the size and shape of the orography and atmospheric conditions, precipitation cell developed on the lee side of mountain as well as upstream side. These orographic effects are important for the heavy rain formation.
(f) On the basis of these results, we synthesize and summarize main problems in prediction of heavy rain formation and its predictability.
Report (4 results)
Research Products (29 results)