暴雨过程环境涡散场能量收支特征

The Characteristics of Budget for Divergent and Rotational Components of Kinestic Energy in Heavy Rain Processes

选取伴有低空急流和不伴有低空急流的两个暴雨过程,分别应用涡散场能量收支方程,计算雨区面积—时间平均的能量收支各项量值,给出对流层上(400—100hPa)、中(700—400hPa)、下(1000—700hPa)各层次的涡旋场和散度场动能的源汇特征。了解到两类暴雨过程的散度场动能制造、转换和输送情况是完全相同的,主要差异反映在对流层中、下层的涡旋场动能收支方面,尤其是旋转风动能制造项,两者符号相反。

From budget equations for rotational and divergent components of kinestic energy, the area-time averages of each term are computed for 1000—700, 700—400, and 400-100hPa layers to describe energetics of the lower, middle and upper troposphere for heavy rain cases with and without LLJ. The results show that the generation, conversion and transport for divergent components of kinestic enery are the same and the major differences between the cases are found in the energy budget of rotational component in lower and middle tropospheric layers. In particular, the signs of rotational generation (GR) are opposite.