2007—2012年夏季中国青藏高原以东地区MCC的分布特征

用FY-2D和FY-2E地球静止卫星相当黑体温度资料,对2007—2012年夏季(6—8月)中国青藏高原以东地区的中尺度对流复合体(MCC)进行普查分析,并分为MCC和类MCC(偏心率在0.5~0.6之间),共计190个MCC和62个类MCC。西南和华南地区的MCC和类MCC占总数的60%,华东和华中地区占总数的27%,东北、华北和西北地区最少。两类MCC的生成源地和消散地的海陆性质相同。东北和华北地区MCC主要向东北移动,华中和华东地区MCC向东南移动。华南和西南地区的MCC移动方向具有多样性,大多为不移动类型。从月际变化来看,MCC在6月份最多,类MCC在7月份最多。MCC的日变化具有区域性特征,西南地区的MCC在22:00—23:00是形成高峰,03:00—04:00达到成熟,06:00—08:00开始消散。东北、华北、华中和华东地区的MCC形成高峰在16:00—18:00,19:00—23:00和02:00—03:00是成熟高峰,21:00—01:00消散。华南地区的MCC主要形成在23:00—03:00,11:00—14:00成熟,14:00—15:00消散。

Distribution characteristics of MCCs in eastern Tibetan Plateau in summer from 2007 to 2012

Based on the FY-2D and FY-2E geostationary satellite black body temperature(TBB) data in summer (June to August) from 2007 to 2012, the mesoscale convective complexes(MCC) in the eastern Tibetan Plateau of China were investigated and were classified into MCC and similar MCC(0.5-0.6 eccentricity).Results reveal that there were 190 MCCs and 62 similar MCCs in summer during 6 years. 60% MCCs and similar MCCs occurred in southwest China and south China, 27% in central-eastern China, but in northeast China, northwest China and north China they occurred the least. The land and sea properties of formation and dissipation regions of the two types of MCCs were similar. MCCs in northeast China and north China moved towards northeast; while in central-eastern China, mainly to southeast. Most of the MCCs in south China and southwest China moved in various directions, and most of them were almost stagnant. MCCs happened most in June while similar MCCs in July. The diurnal variation of MCC differed one from another: in southwest China, it formed at 22:00-23:00, matured in the early morning of 03:00-04:00 then dissipated in the morning of 06:00-08:00; in northeast China, north China, central and eastern China, it generated in the afternoon of 16:00-18:00, matured at night of 19:00-23:00 and in the early morning of 02:00-03:00, finally dissipated at night of 21:00-01:00; in south China, it formed around midnight of 23:00-03:00,matured around midday of 11:00-14:00 and disappeared at 14:00-15:00.