A note on propagating rainfall episodes over the Bay of Bengal
A note on propagating rainfall episodes over the Bay of Bengal
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DOI：
10.1002/qj.246
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发表时间：
2008-04
影响因子：
8.9
通讯作者：
Changhai Liu;M. Moncrieff;J. Tuttle
中科院分区：
文献类型：
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作者：
Changhai Liu;M. Moncrieff;J. Tuttle
利用TRMM实时多卫星降水分析(MPA-RT)产品，对孟加拉湾及邻近沿海地区三个暖季(即2002-2004年的5月至9月)的降水事件进行了观测分析。降雨时段的时间-距离图(霍夫米勒图)显示，频繁的移动降水时段的寿命远远超过单个对流系统的寿命。与以前在中纬度和热带大陆上记录的那些通常有转向水平的事件不同，大多数事件向南移动，许多事件似乎没有转向水平(即它们以类似液压的方式传播)。平均而言，相干系统的纬度跨度为5度，持续时间为1天，经向传播速度约为8m S−1。这些事件大多在中午左右在沿海地区开始，在午夜左右在离岸地区开始。版权所有©2008皇家气象学会
An observational analysis of precipitation episodes over the Bay of Bengal and the adjacent coastal region is conducted using the TRMM Real‐Time Multi‐Satellite Precipitation Analysis (MPA‐RT) products for three warm seasons (i.e. May to September for 2002–2004). Time–distance diagrams (Hovmüller diagrams) of rainfall episodes reveal frequent travelling precipitation episodes having lifetimes greatly exceeding those of individual convective systems. The majority of the episodes translate southward and many do not appear to have a steering level (i.e. they propagate in a hydraulic‐like manner), unlike those previously documented over midlatitude and tropical continents which usually have a steering level. On average, the coherent systems have a latitudinal span of 5 degrees and a 1‐day duration and a meridional propagation speed of 8 m s−1, approximately. The episodes mostly initiate over the coastal land around midday and offshore around midnight. Copyright © 2008 Royal Meteorological Society