用气象要素确立的当地发生沙尘暴的可能性指数

A Descriptor for the Local Dust Storm Occurrence Probability Constituted by Meteorological Factors

摘要: 本文利用甘肃省60 个测站1954-2005 年间春季17 个气象要素处于不同大小等级时沙尘暴发生的频率，有效建立了表征和判断某日沙尘暴发生可能性的气象指数，并据此给出判断某日沙尘暴能否发生的气象判据，为预报沙尘暴和填补历史资料提供了一条新途径。分析表明：一般而言，要素与沙尘暴的关联程度越大，其对沙尘暴事件能否发生的影响强度也越大；各要素与沙尘暴的关联程度及其对后者的影响强度具有明显的区域性差异；就全省而言，所研究要素中最大风速、风速、最大风速风向、日照时数、蒸发量、相对湿度、最小相对湿度、最低气压以及水汽压与沙尘暴的关联程度最大，它们对沙尘暴的影响强度也是最大的。

Abstract: Based on the daily data sets of 17 meteorological factors during the period of 1954-2005 for 60 gauge stations distributed over Gansu Province of China and the corresponding dust storm records, the dust storm probabilities related to different classes of each factor have been calculated and analyzed. On the basis of the analysis, a meteorological descriptor quantifying the daily dust storm happening probability for each station, which is referred to as the dust storm occurrence probability index (DSOPI), has been effectively established. According to the statistical characteristics of DSOPI for each station, a feasible judging criterion for a dust storm event, which can greatly contribute to forecasting dust storms and filling up the unavailable historic dust storm records, has been determined. The average daily dust storm probability related to each factor on the dust storm day has been specially analyzed for all the stations, indicating that, generally, the more significant one factor’s influence on dust storms, the greater its contribution to them; each factor’s contribution greatly varies from place to place; among all the involved 17 factors, the maximum and mean wind speeds, the maximum-speed wind direction, the sunny hours, evaporation, the mean and smallest relative humidity, the lowest surface air pressure and the vapor pressure contribute to dust storm events in Gansu Province most greatly in order.