修正的质量通量积云对流方案及其模拟试验研究Ⅰ:方案介绍及对1991年洪涝过程的模拟

文中在综合比较各类积云对流参数化方案优缺点的基础上 ,主要参考陈伯民等修正的ECMWF质量通量积云参数化方案 ,对其进行简化和修改 ,发展了一个质量通量积云对流参数化方案 ,文中表示为 MFS(Mass Flux Scheme)。MFS是一种综合型的方案 ,既考虑了大尺度水汽辐合的重要性 ,又考虑了积云中的上升运动、下沉运动、环境中的补偿下沉运动 ,以及卷入、卷出和蒸发等 ,用总体云模式来描述积云与环境的相互作用 ,同时考虑了深对流和浅对流。将 MFS植入 NCAR区域气候模式 Reg CM2中 ,对 1 991年 5～ 7月江淮地区特大降水过程的夏季风气候特征和变化进行了模拟 ,并与 NCAR Reg CM2选用 Kuo方案 ,在同样初、边值条件和其它物理过程选择下的模拟结果进行了对比分析。分析结果表明 ,植入 MFS后的模式能够模拟这次极端的降水气候事件。在某些方面 ,如地表气温 ,降水的模拟上 ,植入 MFS后的模式的模拟结果要比原模式的结果更合理

MODIFIED MASS FLUX CUMULUS PARAMETERIZATION SCHEME AND ITS SIMULATION EXPERIMENT PART I: MASS FLUX SCHEME AND ITS SIMULATION OF THE FLOODING IN 1991

Based on the existing cumulus parameterization schemes, a Mass Flux Scheme for cumulus convective parameterization, i.e. MFS, has been successfully developed by referenced the work of Chen Bomin. MFS is a comprehensive scheme. In MFS, not only the importance of the large scale moisture convergence is taken into account, but also it includes the cumulus updrafts, cumulus downdrafts, cumulus induced subsidence in the environmental air, entrainment, detrainment and evaporation. The interaction between the cumulus and the environment is described by using a one dimensional bulk model. At the same time the scheme includes the penetrative and shallow convection. The MFS has been successfully imported into the regional climate model RegCM2 developed by NCAR. The new model has been applied to simulate summer monsoon characteristics and their variations of heavy rainfall process in the Changjiang Huaihe River Basin for three months from May to July 1991. The results show that the new model can successfully simulate this rainfall process. By comparison the model outputs of RegCM2 using the Kuo scheme and the MFS, it is found that the MFS is better in the surface temperature, rainfall area, rainfall period of time and the intermission simulation.