黑风暴的沙尘形成与输送参数化及中尺度数值试验

PARAMETERIZATION OF THE FORMATION AND TRANSPORTION FOR SAND DUST OF THE BLACK STORM AND MESOSCALE NUMERICAL EXPERIMENTS

西北地区典型黑风暴和强沙尘暴都是在特定大尺度环流背景和中尺度系统相互作用下发生和发展的，而中、低空强锋区相伴的强冷锋移经沙源充足的大沙漠区是黑风暴和强沙尘暴形成和发展的必要条件。为了研究黑风暴和沙尘暴的沙尘形成、输送及沉降机制，本文提出了一种沙尘源、汇项的参数化方案和一个沙尘输送方程，进而引入已有的ＭＭ４中尺度数值模式模拟系统；应用这个改进和发展的模式模拟系统基本成功地模拟了“９３．５”黑风暴的天气系统演变及其沙尘浓度的近地层和垂直分布以及沙尘的沉降与输送。模拟结果分析表明，用包括沙尘输送方程及其沙尘源、汇项参数化方案的中尺度数值模式来研究黑风暴的沙尘形成、输送和沉降机制是一种具有应用前景的方法。

The results indicated that the typical black storm and severe sand dust storm in the Northwest Region were generated and developed under an interaction between the special large scale circulation pattern and mesoscale systems, the severe cold front with intensive front zone on mid and lower levels moved along a huge of desert with abundant sand source to be a necessary condition for a black storm and a severe sand dust storm.In order to study the mechanism on the formation and transportion as well as sedimentation for sand dust of the black storm and sand dust storm, a parameterized scheme of sand dust source and sink term and an equation of transporting sand dust were achieved and posed, while both the scheme and the equation were introudced to the mesoscale model and simulation system for MM4 which have been done. We appiled the improving and developing model and simulation system to achieve basically successful simulations for the evolution of weather systems and the distribution of the sand dust concentration in both the vertical and surface layer , as well as the sand dust sedimentation and transportion of the “93.5” black storm . The analysis of simulating results shown that it is a quite well method with applying prospects to study a mechanism of the formation and transportion as well as sedimentation of sand dust of the black storm by using mesoscale numerical model included the equation of transporting sand dust and parameterized scheme of the sand dust source and sink terms.