陕西一次强沙尘暴过程诊断与分析

2006年陕西共发生沙尘天气13次,其中4月11日的沙尘天气最为严重,危害最大,这也是陕西近10 a来最为严重的一次沙尘暴天气过程。这次沙尘天气带来一系列的天气演变过程,它持续时间虽然只有8~9 h,但覆盖面积大,影响范围广,全省70%~80%左右的区域都受到了影响。运用FY-2卫星红外云图及MICAPS2.0模式中的数值预报进行分析,发现红外云图呈现出异常状态,高低空形势配合较好,气压梯度、温度梯度密集,狂风突起等状况,试图揭示与解读沙尘天气在发生过程中某些气象因子的特征及其对沙尘天气的影响机理,为今后预报沙尘暴强度和发生区域提供一定的理论依据。

Diagnosis and Analysis on a Severe Sandstorm in Shaanxi

There were thirteen sand-dust weather processes in Shaanxi province in 2006, in which the process on April 11 was the most serious, and also the most serious in the last 10 years in Shan'xi. This sand-dust weather process induced a series of development of weather process; although it only lasted for eight to nine hours, it influenced most area, 70% to 80% of the whole province. In order to reveal the characteristics of some meteorological factors in the process of sand-dust weather and its mechanism, the numerical forecast in FY-2 satellite infrared cloud image and MICAPS2.0 model about this sand-dust weather process was analyzed in this study. The results showed that there was abnormal state in infrared cloud image: suitable match of high and low altitude position, abnormal denseness of pressure and temperature gradient and burst of gale. The results of this study can provide some theory basis for the forecast of the level and the occurrence region of sandstorm.