Mesoscale Convective Complexes over the Southern China Mainland
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摘要: 根据日本GMS资料和部分常规资料,对我国南方地区春末夏初的10个中尺度对流复合体(MCCs)做了分析。它们的基本特征与美国MCC相近。它们主要活动在夜间,一般在山地背风一侧斜坡上或坡底附近形成;并在对流层中低层中低纬度地区几个天气系统的迭加处获得发展;向东偏南方向移动,与700~500 hPa之间的平均气流方向大体一致,冷云罩面积约为1.4×105 km2,比美洲的(2~3×105 km2)略小;持续时间为12小时左右,比美洲的(10小时)稍长。云区形状呈椭圆形,但偏心率≥0.6。云顶最低温度一般在-86℃以下,出现在冷云罩面积达到最大之前4~6小时。Abstract: Ten mesoscale convective complexes (MCCs) over the southern China mainland during late spring and early summer were computed and analysed using GMS S-VISSR data and conventional data. The results show that they are nocturnal and initiate at slope or near slope bottom of plateau or mountains leeward, and develop at the special favorable area where several synoptic systems from low- and mid–latitude are merging or interacting with each other. They move toward east by south and tend to the mean flow in 700~500 hPa layer. The cold-cloud-shield is about 1.4×105km2, which is smaller than that of MCC in the America ((2~3)×105km2), but it lasts for about 12 hours while the American shield about 10 hours. The eccentricity of cloud shape (≥0.6) is slightly smaller than that in the America (≥0.7). The minimum temperature of cloud top is generally colder than -86℃, which appears 4~6 hours earlier than the time of the maximum cold-cloud-shield extent
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