东疆沙尘暴天气的分析

Analysis of Sandstorm in East Xinjiang

对1961～2001年东疆6个气象站沙尘暴资料的分析表明:东疆沙尘暴高发区在平原地区,主要出现在3～7月,4月份最多。沙尘暴多出现在午后到晚上,傍晚最多,持续时间多在1.5h之内。东疆局地和区域性沙尘暴天气过程,从80年代到90年代减少明显,年平均气温的升高和降水的增多是造成这种变化的主要因素。

By using the surface observational data in weather table 1 of 6 stations in East Xinjiang from 1961 to 2001, the characteristics of sandstorm were analyzed. The results are follow: ①The sandstorm occurs most frequently in plain. Most sandstorms appear within the time from March to July, and most frequently appear in April. Sandstorms frequently occur from afternoon to night, and most frequently in the evening. The persisting time of sandstorm is mainly within 1.5 hours. ②There were 700 local sandstorms and 122 regional sandstorms occurred in East Xinjiang. The regional sandstorms were caused mainly by cold air from west and north-west directions, occurred chiefly within March to May and generally lasted one day, most frequently appears in Nomhu and Hami. The times of sandstorms weather process decreased obviously since 80’s to 90’s, the main factor of such change were the rise of annual mean temperature and increase of precipitation.