Abstract:

The spatial and temporal evolution(haracteristics of spring sandstorm in Qinghai province and the impac[of abnormal(irculation and sea temperature on sandstorm weather are analyzed. The results show that high frequency()((urring sandstorm is in Chaidamu basin, northwest of Qinghai Lake and south of Qinghai province.From 1960s[()the beginning of this(entury, the sandstorm weather has been generally decreasing, in 1960s
sandstorm()((urring in north of Qinghai province was much more than that in south, in 1970s it began[()<1e(reuse in north and increase in south, and in 1980s it began[()decrease generally, after 1990x, it presented a de(reusing tendency with fluctuation, moreover, at the beginning of 1980x, a significant fluctuation from high[()low frequency()((urred in the most part of Qinghai province. The sandstorm weather in Qinghai province has a(lose
relationship with 500 hPa height field in March -May and in previous period of December[()February, especially in March-May, as the anticyclone ridge is getting in(reusing/de(reusing and the Monggolia low trough is getting deepening/decreasing,(old air activity is getting more/less and sandstorm weather in spring()((urs more/less. An<1 this kind +f temporal(hanging tendency of sandstorm and abnormal weather situation are(onsistent with that in northern China. The sandstorm in spring in Qinghai province is(lowly(onnected with sea temperature of India Ocean, when the sea temperature in north of India Ocean has been ascending/descending in previous period of March[()August, the sandstorm weather in spring is getting less/more.

Key words:  sandstorm, decadal variation, weather condition

摘要：

主要分析了青海春季沙尘暴空间、时间演变特征及异常大气环流、海温对沙尘暴天气的影响。结果表明，青海沙尘暴高发区位于柴达木盆地、青海湖西北部、海南南部3地;2o世纪60年代至本世纪初青海沙尘暴天气总体上是减少的。过程次数2o世纪60年代青海北部较多、南部较少，70年代北部开始减少、南部回增，80年代开始整体减少，进入90年代后旱波动式减少趋势，且在80年代初大部分地区发生了一次由高向低的显著波动;青海沙尘暴天气与前期12-2月、同期3-5月500 hPa高度场相关密切，尤其是同期3-5月，当鸟拉尔山高压脊加强(减弱)，蒙占低槽加深(减弱)，冷空气话动频紧( 减少)，青海春季沙尘暴天气偏多(少)，这种沙尘暴的时间变化趋势和异常天气形势与我国北方一致。青海春季沙尘暴与前期印度洋海温关系密切，当前期3-5月、6-8月印度洋中北部海温持续偏叔低)，青海春季沙尘暴偏少(多).

关键词: 青海沙尘暴, 年代际变化, 气候背景