【摘要】 将 2 0 0 3年春季我国的沙尘天气与 2 0 0 0～ 2 0 0 2年以及 1 961年以来的同期状况进行比较 ,分析了 2 0 0 3年春季我国沙尘天气异常偏少的特点。结果表明 :2 0 0 3年春季我国沙尘天气的频次、强度及影响范围是近 4年来最少、最弱、最小的 ;沙尘多发期也是近 4年来出现最晚且持续时间最短的 ;2 0 0 3年的沙尘天气仅多于 1 997年 ,是 1 961年以来的次低值。此外 ,从沙尘天气的动力条件和物质条件入手 ,探讨了 2 0 0 3年春季我国沙尘天气异常偏少的形成原因 ,指出 :影响我国的冷空气势力偏弱、路径偏西、气旋偏少 ,同时北方地区 (特别是主要沙尘多发区 )降水明显偏多、干土层偏少、内蒙古中西部地区持续积雪等因素 ,共同造成了沙尘天气显著偏少、偏弱。更多还原

【Abstract】 Compared with the dusty weather in the spring of 2000～2002 and that since 1961, the characteristics of abnormal decreasing of dusty weather in China in the spring of 2003 was analyzed. The results show that the happening of dusty weather in 2003 was the weakest in the recent 4 years in terms of frequency, intensity, and area affected. The high frequency period was the shortest and appeared relatively late. The total number of dusty weather days in the spring of 2003 exceeded only that in 1997, taking the second place since 1961. In addition, the reason of abnormal decreasing of dusty weather in the spring of 2003 was explored from the dynamical condition and material condition. The results show that the number of cyclones influencing China was relatively small, the power of cold air systems was weak and their tracks were located westerly. At the same time, in the northern part of China, especially the central dust affected areas, the amount of precipitation was above the average of the recent years, the number of stations with dry soil layer was fewer, and there was lasting snow cover in the west and central part in the Inner Mongolia.更多还原