从气象卫星资料揭示的青藏高原夏季对流云系的日变化

ON THE DIURNAL VARIATION OF CONVECTION OVER QINGHAI-XIZANG PLATEAU DURING SUMMER AS REVEALED FROM METEOROLOGICAL SATELLITE DATA

中文关键词:  气象卫星资料  青藏高原  对流云系  日变化

英文关键词:Data of NOAA Satelli to/USA  Qinghai-Xizang plateau  Convection cloud system  Diurnal variation of convection

中文摘要:

      文中利用日本静止气象卫星观测的1981～1994年1天8次的TBB观测值和1978～1994年NOAA卫星观测的1天2次OLR观测值研究了青藏高原地区夏季对流云系季节变化以及对流云的日变化及其东西向移动规律,并对1994年的资料进行了个例分析。结果表明,青藏高原夏季对流云有极为明显的日变化,以00～05SUTC为最弱,15～17UTC最强。在季风雨爆发后的7月中旬到8月上旬在高原中部(30～32°N,90°E)、东部(30°N,97°E)和西部(30°N,85～87°E)有3个TBB低值中心,多年月平均对流中心区云顶高度可达9.6km,而旬对流中心个别地区平均可达13km。对流云区开始发展于东部地区,随后对流云中心逐步向西移动,并于7月中下旬达到最西,此时西部地区从多年平均而言可以有短暂的强对流发展。

英文摘要:

      Using of the eight times per day TBB dataset observed by GMS/JAPAN during the year from 1981 to 1994 and the two times per day OLR dataset observed by NOAA Satellite/USA, the diurnal and seasonal variation of convective cloud system over Tibet and its zonal movement are studied. The results show that there is an obvious diurnal variation of convective cloud over Qinghai-Xizang Plateau during summer. The convection arrives its strongest hour in 15-17UTC and its weakest hour in 0-5UTC. During the period from the middle ten days of July to the first ten days of August after the onset of summer monsoon, there are three low value centers of TBB which are located over the central part (30-320°N.900°E).the eastern part (300°N. 970°E) and the western part (300°N, 85-870°E) of Tibet.The monthly climate height of cloud top can arrive to 9.6km and the ten days average height in some region can arrive to 13km. The convective cloud begins to develop in the eastern part, then moves westwards and arrives to the west part in the middle and last ten days of July. During that time, the deep convective cloud can temporally develop in the western part of Tibet. Besides. the feature of convective cloud is also analyzed for the summer.1994.