2002年春季中国沙尘天气与物理量场的相关分析

通过对2002年春季中国沙尘暴、扬沙、浮尘天气的综合分析，给出了各沙尘区沙尘天气发生的频率。并分析了沙尘天气分别与850hPa全风速、散度，500hPa全风速、散度、涡度、总能量、垂直速度，不稳定度指数Ki、Ky和Si，300～850hPa两层之间的风切变等11个物理量场的相关性。结果表明：2002年春季沙尘天气，除了具有往年的阶段性特点外，还具有明显的区域特点，即南疆区浮尘较多；河套区扬沙较多；蒙古区沙尘暴较为明显。沙尘天气与各物理量场的相关分析进一步证实，风是影响沙尘天气发生的最主要的气象要素，它与浮尘的出现有一定关系，但不是决定因素；而扬沙和沙尘暴的发生，风确是先决条件。

Correlative Analyses between Meteorological Elements and Dust-stormy Weather Occurred in China during the Spring of 2002

In this paper the frequency of dust\|stormy weathers such as dust storm, wind\|blown sand and floating dust have been presented by analyzing the data of dust\|stormy weather occurred in China during the spring of 2002. And the correlations between dust\|stormy weather and meteorological elements have been analyzed also, the meteorological elements included wind speed and divergence on 850 hPa layer; wind speed, divergence, vorticity, total energy and vertical velocity on 500 hPa layer; instable index, vertical difference of wind speed between 850 hPa layer and 300 hPa layer. In the spring of 2002,the dust\|stormy weather have obvious regional characteristics besides common periodical characteristics, namely the frequency of floating dust is higher in South Xinjiang region than in the other regions; the frequency of wind\|blown sand is the highest in Hetao area; the frequency of dust storm is the highest in Mongolia area. It has further been confirmed by correlative analyses between dust\|stormy weather and meteorological elements that wind is the most important meteorological element for formation of dust\|stormy weather. Although wind may affect the formation of floating dust, it is not a determinant factor. However wind is a determinant factor for the formation of wind\|blown sand and dust storm.