内蒙古草原浅对流云特征卫星观测分析北大核心CSCD

浅对流云(Shallow Convective Cloud,SCC)对于认识和预报深对流强雷暴、辐射平衡以及气候变化有着十分重要的科学和意义。然而浅对流云水平、垂直尺度较小,并且生命尺度短,对其观测技术有限,目前针对浅对流云的观测研究仍然较少。本文采用2009~2010年CloudSat、CALIPSO(Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation satellite)和MODIS(Moderate-resolution Imaging Spectroradiometer)卫星融合产品2B-CLDCLASS-LIDAR和2B-GEOPRO对SCC进行研究,研究分析表明内蒙古草原区域SCC出现频率有明显季节变化,主要发生在夏季和秋季,其出现频率水平分布呈现西北低、东南高的趋势,与海拔梯度变化密切相关。SCC平均云底高度,8月最高,12月最低,呈现明显的冬夏差异。通过比较不同地区SCC云底高度发现,随着观测区域海拔高度增加,SCC云底高度有上升趋势。除此以外,海拔越高SCC云底高度变化幅度越大。

Characteristics of Shallow Convective Clouds over Inner Mongolia Grassland Derived from Satellite Observations

Understanding of shallow convective clouds (SCCs) is important for forecasting deep, convective thunderstorms and studying radiation balance and climate change. Because an SCC has very small horizontal and vertical lengths and a short lifetime, the ways to measure SCCs remain limited. In this paper, we use 2B-CLDCLASS-LIDAR and 2B-GEOPRO from CloudSat, CALIPSO, and MODIS (Moderate-resolution Imaging Spectroradiometer) for 2009–2010 to study SCCs. The test case shows that this method is reasonable and feasible. The analysis shows that the occurrence frequency of SCCs above Inner Mongolia grassland has obvious seasonal variations and is greatest in summer and autumn. The horizontal distribution of its occurrence frequency shows a low trend in the northwest and high trend in the southeast, which is closely related to the altitude gradient. The average cloud base height of SCCs obviously differs between winter and summer, being highest in August and lowest in December. SCCs in different regions show that their cloud base heights trend releated with altitude.