| In this paper, AREM (Advanced Regional Eta-coordinate Model) will be researched. Also, land surface model CLM which has already coupled with AREM and nonlocal boundary layer scheme of CCM3 which has already introduced in AREM will be researched together.Weather analysis is done to heavy rain occurred in Yaan during 1 June to 30 August 2004. The result show that the scale of torrential rain in Yaan is relative small, most of them belong to meso-P scale;all of them company with obvious wet and warm flow transported to torrential rain area. But in different period, moisture source place is different, in June, subtropical high location is relative east and it's influence is relative weak, main moisture come from Bay of Bengal. During last dekad July to first dekad August, subtropical high extend westward to 110~105° E, moisture is mainly come from South China Sea along with south-east or south flow in the west of subtropical high. While in middle dekad of August, moisture with high energy and high humidity is transported from east ocean to Yaan by the strong eastly jet flow in north outside of landing typhoon depression;middle-scale wind convergence in lower troposphere is existed in almost all of heavy rain case. warm and wet air in lower level is lifted upward by this convergence, then convective instability is aroused, which lead to the occurrence of torrential rain;Short wave trough between middle and high latitude in 500 hpa is one of important trigger of heavy rain in Yaan, but not all of heavy rain company with low-pressure system in 500 hpa. Also, numerical simulation of torrential rain in Yaan is conducted by AREM(Advanced Regional Eta-coordinate Model), the comparing analysis between simulated result and observational date show that, false simulated or false intensified middle-scale vortex in 850 hpa by AREM is the main reason of false prediction of torrential rain in Yaan by model.CLM(common land model) is validated by using the field experiments data over desert and cropland in naiman of neimeng province in China respectively. The results of this validated test show that CLM can effectively simulate the characteristics of radiation flux and thermal conduction of soil in both desert and cropland tests. Furthermore, the simulation of CLM can realistically reproduce the response of thermal conduction in soil to weather process which happened during the test period. But in comparing, as for the simulation of longwave radiation flux in whole test period and shortwave radiation flux in dry period, the result of desert test is better than that of the cropland test, because vegetation and soil feature of cropland is more complicated than those of desert, and to specify them exactly is unpractical, which cause the simulative difference of albedo and land surface temperature in cropland test. But for the simulation of thermal conduction, the result of cropland test is better. This indicate that CLM has a better thermal conduction simulating ability to such land surface as cropland which has big water content and is good at maintain water while has a worse ability to those dry land surface as desert.The test of CLM coupled with nonlocal boundary layer model indicated, Imposeed with atmospheric force and driven by NCEP analysis data, CLM can still describe land surface character realistically, both the simulation of soil temperature and sensible heat flux agree well with the observation. The test of added a near land surface layer in boundary layer indicated, by added with a near land surface layer, the soil temperature and sensible heat flux simulated by coupling model agree better with the observation. The sensitive test of different vertical resolution in boundary layer indicated, the simulation of wind, temperature and special humidity in atmosphere is influenced obviously by the difference of vertical resolution in boundary layer.
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