3.19沙尘暴爆发机制分析

【作者】 肖贤俊；

【导师】 何金海； 刘还珠；

【作者基本信息】 南京气象学院 ， 气象学， 2003， 硕士

【摘要】 沙尘暴是我国冬春季节常发生的一种灾害性天气现象，对其作深入研究有利于业务预报的进展。本文在前人的研究基础上，拟就沙尘暴的爆发机制作进一步探索。本文用国家气象中心引进的邵亚平先生的沙尘暴集成预报模式对2002年3月分发生在我国的一次特大沙尘暴作诊断分析与敏感性试验。诊断分析表明，这次沙尘暴由蒙古气旋后部冷锋锋生产生的偏西北大风引发。近地面风速的垂直切变和地面热通量的加大，都可使使边界层湍流加强扬起地面沙尘。地面锋区附近风场的强水平切变，锋面垂直环流及锋后斜压转换的作用，将地面卷起的沙尘带到高空，爆发强沙尘暴。最后本文通过动力稳定性对起沙影响的敏感性试验证明了低层大气的动力不稳定能增强起沙。更多还原

【Abstract】 The dust storm is a disaster weather phenomenon which often occurs in spring and winter in north of China. A Computational Environmental Modelling System from Dr. Yaping Shao is applied to the sand storm over China in March 2002, and the predictions are in good agreement with meteorological records and satellite images. A dynamical diagnose Based on the data from the model presents us more information than real meteorology record about the outbreak mechanism of the sand storm. It is caused by the frontogenesis of cold front connected with Meng Gu cyclone. Large amount of avaikble potential energy convert to dynamic energy in the baroclinic mesosphere. It result in frontogenesis. As the strong normal share of the wind, turbulent fluctuation is strengthened and the sands are raised up from the surface ground The wind speed in the atmosphere of the low level has a horizontal share and this pushes the sands in the atmosphere aggregate, so the visibility descend. A strong sandstorm is produced. A sensitive experiment is also performed to prove that dynamical instability of low level atmosphere would strengthen the entrainment of the sand particles in surface.更多还原