基于TRMM卫星探测的南海及周边地区降水、云和潜热特征的比较研究

利用1998—2013年热带测雨卫星（TRMM）3A12资料，对南海及其周边地区降水、云和潜热的三维特征及其变化进行了对比研究，把南海及其周边地区分为四个区域:华南地区、中南半岛、马来群岛、南海。结果表明:（1）地面降水率EOF分析的第一、二模态方差贡献率分别为57.16%和8.72%，第一模态向量场均为正值，降水呈现南多北少的分布特征；第二模态向量场体现了降水变化南北反相的特征，马来群岛降水变化与其他三个区域反相。从两个模态时间系数序列看出，1998—2005年整个区域降水总体减少，区域降水北部增多南部减少；2005—2013年整个区域降水总体增多，区域降水南部增多北部减少。（2）南海及其周边地区降水夏秋季多，春冬季少，降水中心春夏季北移，秋冬季南撤，其中马来群岛夏季降水最少，冬季最多；其它三个区域都是夏季降水最多，华南和中南半岛冬季最少，南海春季最少。（3）赤道附近对流降水为主，23 °N以北区域层云降水为主，5~23 °N之间区域两种类型降水比例随季节变化，其中陆地降水比例随季节变化明显，特别是华南地区陆地夏季对流降水比例大于50%，冬季层云降水比例大于80%；海洋对流降水所占比例普遍大于50%，随季节变化小。（4）云冰、云水含量水平分布大值区与降水大值区相对应；二者随高度先增加后减少，云冰在13 km高度达到最大值，云水在2.5 km高度达到最大。春冬季，马来群岛云冰含量最大；夏秋季，南海云冰含量最大。云水含量在四个季节都以南海最大。（5）潜热加热率水平分布大值区与降水大值区相对应；随高度呈双峰分布，峰值分别出现在1~2 km高度和4 km高度处，春冬季马来群岛潜热加热率最大。 

COMPARISON STUDY ON PRECIPITATION、CLOUD AND LATENT HEAT CHARACTERISTICS OVER THE SOUTH CHINA SEA AND ITS SURROUNDING AREAS BASED ON TRMM

By using 1998—2013 the Tropical Rainfall Measurement Mission (TRMM)data 3A12, the three-dimensional structure and seasonal variability of the rainfall, cloud, and latent heat over the South China Sea (SCS) and its surrounding areas is investigated. For comparison, the SCS is sub-divided into four parts: the South China Region, Indo-China Peninsula, Malaysia; SCS. The results show that:(1) The rainfall distribution is highly non-uniform and changes from season to season. Overall, the precipitation is much more in summer and autumn while less in spring and winter. But in Malaysia, it is most in winter and lest summer. While in other three areas, it is most in summer. But the precipitations of both the SCS and Indo-China Peninsula reach their minimums in winter while the precipitation of the SCS reaches the minimum in spring. (2) EOF analysis shows that the first mode variance contribution rate is 57.16%, the precipitation in southern areas is higher than that in northern areas. The second mode variance contribution rate is 8.72%, shows that the precipitations of the south and the north change inversely. (3) The equatorial area is mainly distributed with convective precipitation. To the north of 23 °N, stratiform precipitation is dominant. Over the region between 5~23 °N, the precipitation ratio of two types varies with the seasons, which is obvious over land area, especially in South China, the proportion of convective precipitation over land area in summer is greater than 50%, and the proportion of stratiform precipitation in winter is greater than 80%; The proportion of convective precipitation over ocean area is generally greater than 50%, and its seasonal variation is smaller. (4) The horizontal distributions of cloud ice, cloud water, and latent heat are similar to the horizontal distribution of surface precipitation. The vertical distributions of cloud ice and cloud water in the four regions are different. Both cloud ice and cloud water increase first and then decrease with height. And cloud ice reaches the maximum at about 13km; cloud water reaches the maximum at about 2.5 km. In spring and winter, the maximum of cloud ice is distributed mainly in the Malaysian area. In summer and autumn, the maximum of cloud ice is distributed in the SCS. These four seasons all have a larger content of cloud water in the SCS. (5) Latent heat profiles have a similar bimodal structure: the first peak is at about 1~2 km and the second peak is at about 4 km. In spring and winter, the latent heat in Malaysia is much higher. And in summer and autumn, the latent heat in SCS is much higher.