边界层内冷锋流场的动力学特征

DYNAMICAL CHARACTERISTICS OF THE STREAM FIELD OF COLD FRONT IN BOUNDARY LAYER

中文关键词:  冷锋  边界层  地转动量近似

英文关键词:Cold front  Boundary layer  Geostrophic momentum approximation

中文摘要:

      文中求解了锋面存在时地转动量近似下的大气边界层运动方程,得到了边界层内冷锋流场的一些特征,如冷锋坡度随地转涡度增加而增加,随地转风速时间倾向的增加而增加,随沿锋面传播方向的热成风分量的减少而增加。而边界层内冷锋面上下的流场与锋面坡度、地转风及其时空变化特征有关,共同特点是在冷锋面高度以下有下滑运动,而其上有一层上滑运动区。

英文摘要:

      In this paper, we have solved the motion equation of the at mospheric boundary layer under the geost rophic momentum approximation when a front exists. and obtained the characteristics of the stream field of the cold front in the boundary layer, for example, the slope of the cold front increases with the increases of geostrophic vorticity, the tendency of the geost rophic wind speed, and also increases with the decrease of the thermal wind speed along the motion direction of the front. The stream field below and above the cold front surface in the boundary layer depends on the slope of the front, the geost rophic wind speed and its temporal and spatial distributions. The common characteristics are that there exists updraft motion above the cold front surface and downdraft motion below that.