沙尘天气影响因子的对比分析

对比分析了2002年和2003年春季沙尘天气发生的大气环流及地表条件特征, 并利用具有风沙物理过程的沙尘数值模拟结果和动力诊断技术, 探讨了2002年和2003年典型沙尘天气过程和冷空气过程中大气动力条件的作用。结果表明, 沙尘天气的强度、发生范围主要是由大气的动力条件所决定的, 而沙源区地表特征的变化对沙尘天气的发生起着重要的作用, 沙尘天气的强度和影响范围主要决定于沙尘的垂直输送过程。此外, 还总结出了沙尘天气中垂直输送-水平传输-沉降过程的概念模型。

Comparative Analysis on Causing Factors of Dust Events

The dust weathers both in 2002 and 2003 are compared in their general characters of atmospheric circulations and land surface conditions. The typical events were simulated by numerical dust model with dust emission process to diagnose the dynamical processes in the duration of events. The results show that the strength and the affected area of dust events are mainly depended on the dynamic situations of atmosphere, while the occurrences of dust events are sensitive to the land surface conditions. Further, it is found that the vertical transport process of sand-dust is the controlling factor to the strength and the affected area. Based on the diagnosis a concept model was given for simulating dust transporting vertically transporting-horizontally transporting-depositing.