选取达坂城站为"三十里风区"代表站,根据该站观测资料选取九次春季大风过程,以乌鲁木齐站作为风区上游即山体迎风面代表站,分析大风过程中风区上游大气层结状态。研究结果表明:该地区春季大风发生时,在风区上游即天山北坡迎风面的对流层中层700-500hPa存在明显的逆温层;逆温层平均高度约4000m(610hPa),平均厚度约480m(最厚为1200m),平均强度约0.78℃/hm(最强为4.25℃/hm);冷空气越强逆温层强度越强,大风过程结束后,中高层逆温层消失。根据下坡风相关理论,结合逆温层特征可知,"三十里风区"的大风多是与冷空气翻山密切相关的地形型下坡风,加深了对该地区大风的认识。
According to meteorological observational data of Dabancheng station during 2000 to 2008,nine strong wind processes at 30km wind zone in spring were selected year by year. Background circulations of these processes were analyzed by use of reanalysis data,and the characteristics of inversion at Urumqi station during these processes were studied on behalf of the windward slope of Tianshan Mountains. The results indicated that during strong wind processes,inversions existed at the middle troposphere between 700hPa to 500hPa on windward slope of Tianshan Mountains. The average height of inversions was about 4000m( 610hPa),the average thickness was about 480m( thickest to 1200m),and the average strength was 0. 78℃ /hm( strongest to 4. 25℃ /hm). Inversions were stronger as cold airs were stronger and which became weaker and lower as cold airs were weaker. After strong wind processes,inversions disappeared at the middle troposphere and usually appeared at the low troposphere( below 700hPa). According to downslope theories and the characteristics of inversions at the middle troposphere,strong wind in 30 km wind zone mostly belonged to downslope wind. These conclusions are further deepened the understanding of gale in the region.