2005年雨季“三江源”地区对流云的特征分析

Statistic Analyses on Convective Cloud in Source Regions of Yellow River,Changjiang and Lancangjiang in Rainy Season of 2005

利用2005年6～9月逐日逐时FY-2C气象卫星数值云图资料，计算和分析了青藏高原三江源区域的对流云和中尺度对流系统（s—MCS）的发生频率。结果表明，该区域主要以对流云为主，对流云占总云量的80％以上，利用TBB值得出该区域对流云发生源地主要集中在两大区域，其中以32°～35°N，93°～98°E为主要多发区（称为第一高发区），以35°～37°N，91°～95°E为次多发区（称为第二高发区）；该区域对流云存在着明显的日变化，22：00（世界时，下同）～06：00（上半夜）对流云旺盛，06：～14：00（下半夜）及清晨对流云很少。最后结合地面观测资料给出了云顶亮温与地面降水的关系。

Using the daily and hourly FY--2 meteorological satellite cloud image data in June-September 2005, calculate and analysis the activities frequency of convective clouds and mesoscale convective systems （s--MCS） in source regions of Yellow River, Changjiang and Lancangjiang of the Tibetan Plateau are calculated and analyzed. The results show that, in the region main cloud are convective clouds＇, which accounted for total cloud amount more than 80 %. The sources of convective clouds in the region obtained using TBB mainly concentrated in two regions, namely 32°- 35°N, 93°-98°E was the first main high frequency area, 35°-37°N, 91°-95°E was the the second high frequency area. There is a marked diurnal variation of the convective clouds in the region. The convective cloud is well-developed at 22.00： 06.00 and a few at 06：00-14：00. Finally, combinating with ground observations data, a relationship between the cloud top temperature and precipitation is given.