区域气候模式对中国沙尘天气气候特征的模拟研究

 现有的沙尘天气数值预报模式多选用中尺度天气模式单向耦合起沙模式的方式,不适合用来模拟沙尘气溶胶的长距离输送过程,也无法研究沙尘气溶胶辐射效应对气象场的反馈及气候变化的影响。利用一个耦合沙尘模式的高分辨率区域气候模式,模拟了2001年中国北方沙尘天气爆发的时空分布特征。模拟结果与站点观测结果对比发现,模式能够较好地模拟出中国北方主要的沙尘源地分布及沙尘天气爆发的季节变率。分析不同粒径沙尘颗粒的垂直分布特征发现,沙源地表土壤粒子特征、地形对起沙颗粒的大小都有影响；直径超过5 μm的大粒子是北方沙尘天气的主要成分,而影响长江以南的沙尘天气主要以1 μm以下的小粒子为主。对沙尘传输路径的模拟结果和实况观测发现,来自于不同沙源的沙尘天气其影响的范围有显著差异,模式能够较好地模拟出中国主要沙尘传输路径。

Numerical Simulations of Dust Weather in China Using a Regional Climate Model

Most recent numerical prediction models of dust storm are based on mesoscale numerical model and are nested in one-way mode within dust emission scheme.These models are not suitable to simulation of long-range transport process of dust events and feedback of dust aerosol on meteorological field.In this paper,temporal and spatial characteristics of dust weather in 2001 were simulated using a high resolution regional climate model.Simulation results show that the model has well performance on simulation of the sand source distribution and the seasonal variation of dust events.Vertical distribution of four dust grain size groups shows that both the soil particle size and the topography have significant effect on dust emission.The main components of dust in north China are macro particles exceed 5 m and in south China are particles less than 1 m.The model also has well performance on simulation of transmission paths from different sand sources and on different time scales.