New development of Tropospheric chemical transport model coupled with regional metoeorological model

发展了一个新的在线尘埃示踪模式，并将其与区域尺度气象模式相结合。区域大气模式系统(RAMS；Pielke et al.，1992)作为气象的驱动力，用于模拟区域尺度的三维气象场，包括边界层湍流、云和降水。RAMS中的微物理模块能够模拟中尺度云和降水现象，新的示踪剂模式与RAMS完全耦合，这是一种独特的方法，因为降水、云微物理、边界层湍流日循环等区域气象条件对示踪剂的湿沉积和垂直扩散有重要影响。在线示踪模式与RAMS具有相同的时间步长，使得所有的三维风场、边界层湍流、地表通量和降雨量等在线气象信息都可以直接用于各个时刻的示踪模式。然后对1998年4月发生的亚洲大陆向日本和北美输送黄沙的过程进行了模拟。将所建立的模式应用于东亚硫酸盐输送现象，模型的年度模拟结果与地面观测结果吻合较好。

A new on-line dust tracer model coupled with a regional scale meteorological model was developed. As a meteorological driver, the Regional Atmospheric Modeling System (RAMS ; Pielke et al., 1992) is used to simulate the regional scale 3-D meteorological field including boundary-layer turbulence, cloud and precipitation. Microphysics module in RAMS is capable of simulating meso-scale clouds and precipitation phenomena.A new tracer model is fully coupled with RAMS, and this is a unique approach because the regional meteorological conditions such as precipitation, cloud microphysics, diurnal cycle of boundary-layer turbulence play significant role in the wet deposition and vertical diffusion of tracers. The on-line tracer model runs with same time step as the RAMS, so that all the on-line meteorological information such as 3-D wind field, boundary-layer turbulence, surface fluxes and precipitation amount is directly used by the tracer model at every time step.Urban cloud street was first simulated and intensive evaluation was conducted. Then yellow sand transport episode from Asian continent to Japan and North America that occurred in April 1998 is simulated. Developed model was also applied over east Asian sulfate transport phenomena, and model annual simulation showed the good agreement with surface observation.