【摘要】 建立了包含地形的二维夜间边界层模式,并用该模式对边界层低空急流超地转特征进行了数值研究。结果表明:超地转特征不仅与大气热力稳定度及自由大气波动的非线性平流有关,而且还与大气斜压性、辐射、地形等因子有关。因此,强的低空急流是波动动量水平输送、地形的动力作用、大气热力作用引起的动量垂直输送和地形热力作用的共同结果。更多还原

【Abstract】 In this paper, a two-dimensional model is established for a numerical studyon the low-level jet in the nocturnal PBL with topography involved. Results indicatethat its supergeostrophic features are related not only to the atmospheric thermal stabili-ty and the nonlinear advection of the free atmospheric undulation but alao to such factorsas atmospheric batoclinicity,radiation and topography. Thus the strong low-level jet isthe product of the concurrent effects of the momentum horizonntal transport, the dy-namic and thermal actions of topography,and the momentum vertical transport inducedby the atmospheric thermal action.更多还原