一次沙尘暴过程中的沙地面微气象要素及起沙参数分析

The analysis on the micro-meteorological factors and surface parameters of sand during a sand dust storm

利用在巴丹吉林沙漠北缘拐子湖地区设立的风沙观测实验场获得的资料,分析了2010年4月7日在该地区所发生的沙尘暴过境前后气象要素的变化,计算了这次沙尘暴起沙过程中的一些参数,结果表明:在沙尘暴过境前贴地层风速风向经过了一个波动调整加速过程,在沙尘暴过境时空气处于暖干,沙地面处于高温低湿状态,同时气压和水汽压都会明显下降,所有这些都有利于地表起沙;贴地层风速最大的时段是地表起沙最为严重的时段,该地的100cm临界起沙风速大约为6.5m/s,平均粗糙度为0.0014m;地表摩阻速的平均值为0.29m/s,同200cm高度的风速呈线性相关,拟合方程为y=0.0417x+0.0175,相关系数R=0.9199。

According to the information of the field observation in the northern margin of the Badanjinlin Desert Guaizihu region, we analyzed the changes of meteorological elements that happened on April 7,2010 in the area before and after .the dust storm, and calculated some of the parameters in the sediment. The results showed that before the dust storm, the wind speed and direction underwent a process of fluctuation from an adjustment to an sand moving at 100 cm was about 6.5m/s, the average roughness was 0.0014m; Average surface friction veloci- ty was 0.29m/s. Fitting equation with wind speed at 200 cm was y = 0. 0417x ＋0. 0175, correlation coefficient R = 0.9199.