Climatic Characteristics of Dust Storms in the Middle and West of Northern China
The classification and regional division of temporal variation of dust storms in the middle and west of northern China have been studied by using the observation data (including the occurrence days and beginning and duration of dust storms) from 235 meteorological observation stations during 1954-2005. Based on the classified results of annual patterns, diurnal variation and duration patterns, the regional characteristics of temporal variation patterns of dust storms and their causes are analyzed. The main results are as follows: the annual variations of the number of dust storm days can be divided into four types, namely spring type, winter-spring-summer type, spring-summer type and winter-spring type, and they respectively account for 29.7%, 29.7%, 27.1% and 13.5% of the total number of stations where dust storms happened. The dust storms of three types of them (except winter-spring type) most frequently occur in spring. The diurnal variations of dust storms can be divided into three types according to the frequency distribution of the occurrence time, and there are obvious differences in the occurrence time of the peak among different types of diurnal distributions. According to the temporal statistical characteristics of dust storm duration, the duration patterns can be divided into three types: short-time type, medium type and continuous type. These above classified results of annual patterns, diurnal variation and duration patterns indicate that there are obvious regional differences in the temporal variations of dust storms. The differences are due to the match of the time in which strong wind, dust sources and thermal instability happen in different regions.
number of dust storm daysannual variationdiurnal variationdurationregional characteristic
NETL
NSTL
万方数据
维普
