中尺度模式MM4对高精度水汽输送算法的敏感性试验  

The Sensitive Experiment of a Mesoscale Model MM4 to the High Accurate Water Vapor Algorithms

作　　者：郑爱军[1] 葛孝贞[1] 

机构地区：[1]南京大学大气科学系

出　　处：《大气科学》1997年第3期308-316,共9页Chinese Journal of Atmospheric Sciences

基　　金：国家"八五"攻关课题;国家自然科学基金

摘　　要：水汽输送的算法精度对中尺度模式的预报能力起有重要作用。本文在ＭＭ４的基础上用高精度的平流格式改进模式的水汽输送格式，使改进后的模式包含了对多种高精度的水汽输送格式的选择，如Ｐｒａｔｈｅｒ格式和Ｂｏｔ格式。这些格式都是正定的，在理想风场的数值实验中几乎无数值耗散，无计算频散。我们在Ｂ网格中央差格式（原ＭＭ４中的格式）、Ｕｐｓｔｒｅａｍ格式和Ｐｒａｔｈｅｒ格式等模式选择项下，对１９８２年６月的一次梅雨期暴雨过程进行了数值对比实验。结果表明：１）模式的预报能力对水汽输送格式的精度较敏感，２）高精度的水汽输送格式（Ｐｒａｔｈｅｒ格式）提高了模式对暴雨区、降水场结构、雨团活动的预报能力，较真实地模拟出了尺度较小的降水系统的活动。A mesoscale numerical weather predictive system, which is based on MM4, is developed here by coupling with some more accurate water transport algorithms. These algorithms include the Prather scheme and Bott scheme. Both schemes are positive and produce less numerical diffusion than the Leapfrog (LF) scheme does in the idealized flow tests. Here the LF scheme is a specified form of B-grid center difinite scheme used in MM4. We also simulate a heavy rain case of June 19, 1982 with the model′s water transport options of B-grid center scheme, Upstream scheme and Prather scheme, respectively. The results demonstrate that with the accurate water transport algorithms such as the Prather scheme, the model improves the precipitation prediction and gives more accurate results for the short range precipitation system.

关 键 词：水汽输送 中尺度模式 数值模式 敏感性 

分 类 号：P434.5[天文地球—大气科学及气象学]