关键词: 沙尘天气, 变化趋势, 相关分析, 影响因子, 沙尘指数

Abstract: The authors study the temporal and spatial distributions of dust weathers and the trends in occurring days of dust weathers using data from 28 observational stations in the Tarim Basin during the period of 1961-2003. Five meteorological factors, which affect dust weathers, are analyzed, including air temperature, daily range of ground temperature, air pressure, average wind speed and precipitation on dust weathers with the method of linear multi-regression. Based on the analyses, the indices of dust weathers are constructed. The results show that the regions where dust weathers occur most frequently are in the Taklimakan Desert and its southern marginal zone. The temporal and spatial distributions of dust weathers are different in these regions. Dust weathers occur most frequently in spring. The days of dust weathers are closely related to daily variations of the meteorological factors. Dust-weather days have a tendency toward decrease. Interannual variations of dust-weather days have a period of about 6-9 years. According to their importance in affecting the occurrence of dust weathers, the factors are in an order of average wind speed, precipitation and daily range of ground temperature over March-September. In spring, the dominant factor is precipitation. The dominant factor is average wind speed over June-September. Indices of dust weathers are constructed to demonstrate the temporal series of dust weathers and to predict the occurrence of dust weathers.

Key words: dust weather, trend, correlation analysis, influence factor, index of dust weather