关键词: 两维数值模式, 沙漠, 绿洲

Abstract: In order simulate and research the influence of the features of the Planetary Boundary Layer (PBL) of the oasis and gobi desert and underlying surface on precipitation etc., two-dimension high resolution PBL model coupling with the BATS scheme has been used in this paper.The underlying surface is desert ,in which there are several hundred km long. Resuls shows that oasis transports little sensible heat to PBL,the peak generally is about 60 w/m²,but latent heat is larger,the peak generally is about 400 w/m². Due to the transportation of the sensible heat and latent heat over the oasis, the cold-wet air column appears in the boundary and lower air. The air column can reach a height of 650 hPa, the ground layer and temperature difference can reach 4 ℃, this case is called "oasis cold-wet effect". In the desert region, due to the latent heat transports little, the peak is about100 w/m², but sensible heat transport is largely about 400 w/m², a hot-dry air column formed, it can reach the height of 600 hPa in the boundary layer and lower air over the desert in between the oasis.The maximum ground layer temperature difference is 5℃, this case is called "desert hot-dry effect".The existernce of oasis in the desert and gobi contributes to the precipitation of oasis and the lowerreaches of the oasis. The cold-wet air transported by advection passes over the desert, it mades layer unstable and precipitation increase over desert contiguous to the fringe of the oasis.