摘要
已有研究表明:云的垂直结构(简称CVS)是一个在卫星资料反演和气候模式预测中很重要的云特征。本文通过利用美国2006年刚发射的卫星CALIPSO(Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Obser-vations)所负载的激光雷达Level2_05km的云数据,研究了东亚地区(18°N^53°N,74°E^144°E)云的垂直分布特征。结果表明:东亚地区多层云云量在夏季、秋季、冬季、春季分别为43.6%、29.6%、21.1%、33.3%,而多层云分布中双层云比例最大。云顶和云底高度除了随季节变化显著外,还有明显的区域特征。单层云、双层云以及三层云的云顶和云底高度的数据显示,三层云中最上层的云顶和云底最高,并始终高于两层云中最上层云的云顶和云底高度。平均云层厚度季节变化不明显,其值普遍在0.9~2km范围之间。而云层间距同样没有明显的季节和区域变化,其出现的概率随距离的增大而减小。其中,间距在0.35km的概率最大,占到将近50%。而间距在1.45km附近的概率大约为15%,高一点的可达到20%。
Previous studies show that the cloud vertical structure is an important factor for satellite retrieval and cli- mate simulation. Based on the Level 2_05km cloud data of lidar fixed on Cloud-Aerosol Lidar and Infrared Pathfind- er Satellite Observations （CALIPSO） launched by USA in 2006, the authors study the cloud vertical distribution o- ver East Asia （18°N- 53°N, 74°E- 144°E）. The results show that the multilayer cloud fractions in East Asia are 43.6%, 29.6%, 21.1%, and 33.3% for summer, autumn, winter, and spring, respectively. Two-layer clouds ac- count for the largest proportion in muhilayer cloud systems. The altitude of cloud layer also varies with territories apparently, besides obvious season variatiorL Analysis of the altitudes of cloud top and cloud base for single-layer cloud, two, layer clouds, three-layer clouds show that the top layer of three-layer cloud is the highest layer, the sec- ond is the top layer of two-layer cloud. Mean thickness of cloud layer and the distance between two consecutive lay- ers in a multilayer cloud system have not remarkable seasonal and regional variations. The average thickness of cloud layer ranges between 0. 9 km and 2 kin. But the occurrence probability decreases with the increasing of distance be- tween two consecutive layers. The probability that the distance between two consecutive layers is 0. 35 km is almost 50%, the probability for the distance about 1.45 km is 15%.
出处
《大气科学》
CSCD
北大核心
2009年第4期698-707,共10页
Chinese Journal of Atmospheric Sciences
基金
国家自然科学基金资助项目40575036
40633017
