【摘要】 使用 195 7— 1996年 40年内蒙古中西部 74个地面测站沙尘暴观测资料 ,确定了不同范围强和特强沙尘暴标准 ,给出了强和特强沙尘暴过程的个例谱 ;对其地理分布、时间分布特征进行了详细的统计分析。结果表明 :内蒙古中西部有三个强和特强沙尘暴多发中心 ;强和特强沙尘暴年代际变化、年际变化和日变化显著 ,70年代和 6 0年代次数最多 ,强度也最强 ,80年代开始减少 ,2 0 0 0年、2 0 0 1年又趋于增加 ;在一年内强和特强沙尘暴集中出现在春季的 3～ 5月份 ;一天之中则主要出现在午后到傍晚。文中还对形成上述统计特征的气候学成因作了初步讨论。更多还原

【Abstract】 From the observation data of sandstorms over past 40 years （1957₁996） from 74 meteorological stations located in the west and middle parts of Inner Mongolia, China, 184 strong and very strong sandstorm cases with different scopes were recorded according to a given standard of intensity. Detailed statistical analysis on their characteristics of geographic distribution and temporal distribution are performed. The results show that there are three centers of strong and very strong sandstorm in the west and middle parts of Inner Mongolia. They are located in the Guaizhihu, Alashan Plateau; Zhurihe, west Xilinguole and Yikewusu, North|West Yikezhao respectively. The variations of sandstorm on decade, year and season scales are considerable. After reaching the peak in the 1960′s and the 1970′s, their times and intensity began reducing in the 1980s. However, strong and very strong sandstorms increased suddenly in 2000 and 2001 and appear mainly in March to May of spring, meanwhile in one day they appear mainly in afternoon to early evening. Furthermore, a preliminary study on the climatic causes of forming above statistical characteristics is given.更多还原