北京沙尘天气与源地积雪变化的关系

主要分析了北京沙尘天气变化规律及沙尘源区积雪变化与北京沙尘日数的关系,并探讨源区积雪变化影响北京沙尘天气的机制.研究表明55年来北京沙尘日数基本呈减少趋势,但1998～2000年又有所增加,沙尘暴日数也在减少,近10年北京没有出现强沙尘暴天气.而沙尘源区积雪深度和积雪面积与北京沙尘存在明显的负相关关系.冬季源区积雪减少(增加),很可能导致春季沙尘日数增加(减少),作者认为冬季积雪变化引起的土壤含水量变化是影响春季北京沙尘天气的原因之一.

The Relationship between Dust Weather in Beijing and Snow Cover in Dust Source Areas

Analysis of variation of the sand dust weather and discovery of relationship between sand dust weather in Beijing and the snow in the sand dust storm source areas and analysis of the possible reason about this relationship is presented.It is concluded that dust weather from 1951 to 1998 in Beijing decreased,whereas dust days there increased from 1998 to 2000.Dust storm days decreased too,and there are not dust storms during recent ten years in Beijing.The correlation coefficient between dust days in Beijing and the snow in source areas is negative.The increasing(decreasing) of snow leads to the low(high) frequency of dust storms occurrence during spring in Beijing.One of the possible reasons affecting the frequency of dust weather in Beijing is the variation of the soil moisture resulted from the snow melting during winter in source areas.