1991年夏一次梅雨锋暴雨的能量研究

利用ＭＭ４模式模拟了１９９１年６月３０日００时～７月２日００时一次大暴雨过程．并将输出结果进行了能量平衡的计算。发现动能及其各收支项主要集中在高层；平均有有效位能问动能转换；散度风动能不足总动能的１％，但起着能量转换的中介作用。在暴雨时期，散度风动能、它的次网格转换、来自有效位能的转换以及其向旋转风动能的转换等均达到最大值，说明散度风动能和暴雨有更为密切的关系。

ON THE KINETIC ENERGY BUDGETS OF A HEAVY RAIN PROCESS PRODUCING MEI-YU FRONT IN THE SUMMER OF 1991

In this paper, a numerical simulation was carried out using the PSV/NCAR mesoscale model (MM4), and then the model out--put data was used to evaluate the energy and energy conversions in the period of the strongest rainfall from 00LST 30 June to 00LST 2 July 1991. The computations comfirm that the largest valuse of the kinetic energy and its budget terms appear in the upper layer of the atmosphere and the available potential energy is converted to kinetic energy on the everape. Even though the divergent kinetic energy is less than 1 % of the total kinetic energy, it plays an important role as a bridge in the energy conversions. The energy goes to the rotational kineticc energy from divergent kinetic energy in the upper layer, but conversely in the lower layer. The divergent kinetic energy, the energy transport coming from the available potential energy and sub--grid --scale energy and the energy conversion going to the rotational kinetic energy all showed the forgest values during the heavy rain period. This suggest that the divergent kinetic energy is much closely related to the heavy rain.