关键词: 沙尘暴, 气象要素, 能见度, 地温, 对比分析

Abstract:

Based on the per minute surface meteorological element data of the twice sandstorms cases recorded by sandstorm automatic observation system of Jiuquan base station on March 28 and on July 12 of 2004, the micro meteorological element change characteristics were analyzed. The result indicated that: ①The surface humidity and barometric pressure were both quite low before sandstorms. Surface pressure increased suddenly in the beginning course of the twice sandstorms, then maintained a period of relatively steady states. But the relatively steady period was longer in the spring sandstorm case than that in winter sandstorm case. The surface pressure largely increased once again before sandstorms nearly finished.②The surface air temperature was high before sandstorms happened, but decreased quickly at the end of the course. In the spring sandstorm period, the 0 cm depth earth temperature and surface air temperature change tendencies were quite consistent. But in summer not only the 0 cm depth earth temperature but the 5 cm depth earth temperature variation was consistent with surface air temperature change tendency.③Owning to the difference of the surface characters in different seasons, the horizontal visibility of summer case was bad than the spring courses, although the horizontal wind speed of the spring occurs was obviously bigger than that of the summer sandstorms.

Key words: sandstorms, meteorological element, visibility, ground temperature, contrast analysis