基于TRMM卫星多传感器资料揭示的亚洲季风区雷暴时空分布特征

利用16年（1998-2013）的热带降水测量任务卫星（TRMM）降水雷达和闪电成像仪等多传感器观测资料，分析了亚洲季风区内雷暴和强雷暴的空间分布、季节变化及日变化等气候特征.文中取闪电数大于1的雷达降水特征为雷暴，并将闪电频数在前10%的雷暴定义为强雷暴.结果表明：雷暴活动主要集中在陆地及近海区域，陆地与海洋上的雷暴密度之比约为4.4：1，强雷暴密度之比约为7.4：1.0-10°N纬度带内雷暴数占总雷暴的比例最大（占总数的31.7%），而强雷暴则在20°N-30°N区间最为活跃（34.5%）.雷暴与闪电密度的空间分布在低纬度区域（0-30°N）较为一致，但在中纬度地区（30°N-36°N）呈现出不同的分布特征，即从西部的青藏高原向东部的江淮流域，雷暴密度逐渐减少但闪电密度逐渐增加；而强雷暴与闪电密度的空间分布基本一致.受亚洲夏季风活动影响，低纬度地区强雷暴更容易发生在春季，强中心位于喜马拉雅山南麓东端，次中心位于中南半岛，而中纬度地区在夏季最为活跃，强中心和次中心则分别位于喜马拉雅山南麓西端和中国江淮流域.陆地上雷暴主要集中在午后至傍晚，少数区域受局地环流和气象条件的影响夜雷暴活动频繁，而海洋上雷暴更易发生在午夜至清晨.

The temporal and spatial distribution of thunderstorms in Asia Monsoon Region based on the TRMM multi-sensor database

Based on the 16-year (1998-2013) multi-sensor observation of the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) and Lightning Image Sensor (LIS), the spatial distribution, seasonal and diurnal variation of thunderstorms and intense thunderstorms in Asia Monsoon Region (AMR) have been investigated. The Radar Precipitation Features (RPFs) with flash count greater than 1 are selected as thunderstorm, and the thunderstorms with top 10% flash rate are defined as intense thunderstorms. The result shows that thunderstorms are mainly concentrated in continental and coastal areas, the land/ocean ratio of thunderstorm density is about 4.4:1, and the ratio of intense thunderstorm density is nearly 7.4:1. It is found that the largest proportion of thunderstorms of 31.7% appears in the 0-10°N band, while intense thunderstorms are most active in the 20°N-30°N band which accounts for 34.5%. The distribution of thunderstorm density is similar with that of lightning density in low-latitude region, however, different distribution patterns are seen in mid-latitude region between 25°N-36°N, i.e. the thunderstorm (lightning) density presents an increasing (decreasing) trend from the west (Tibetan Plateau) to east (Eastern China). However, the distribution of intense thunderstorms is similar with that of lightning density in all latitude. Affected by the Asia Summer Monsoon, intense thunderstorms in low-latitude region are more likely to occur in spring, when the strong and sub-center center of intense thunderstorms located at the eastern tip of the South Himalaya Front (SHF) and Indochina Peninsula. While the intense thunderstorms in mid-latitude region is most active in summer, when the strong and sub-center center transferred to the western tip of SHF and the Yangtze-Huaihe river basin, respectively. The continental thunderstorms mainly occur from afternoon to evening, and there are frequent nocturnal thunderstorms in some regions because of the affection of local circulation and meteorological conditions, while the maritime thunderstorms are more likely to occur between midnight and early morning.