关键词: 典型沙尘暴年, 环流特征量, 分析, 春季, 宁夏

Abstract: The data on sandstorm occurred times, conventional meteorological observation, circulation feature, sea surface temperature etc. in nearly 40 years are used to analyze the variety law of sandstorms in Ningxia as well as their relations with influencing factors. It was found out that there is obvious difference in prophase meteorological and circulation features between the years with more and less sandstorms: the shortage of precipitation of previous summer and summer to fall, less activities of cold mass in spring and winter, smaller area and weak intensity of prophase north polar vortex, easterly located and weak of east Asia trough, El Nino distributed type of north Pacific sea surface temperature anomaly previous spring all lead to less spring sandstorm, and vice versa. According to the mechanism of sandstorm it is revealed that the modification of East Asia circulation, weak winter monsoon is the main reason of less occurrence of spring sandstorm in Ningxia on in the background of regional enhanced while degrading totally. The conceptual model of climate trend of spring sandstorm in Ningxia was setup as well.

Key words: typical sandstorm year, circulation feature, analysis, Spring, Ningxia