摘要
利用1999年6月一次典型梅雨锋暴雨过程和敏感性试验的数值模拟结果分析了对流对称不稳定的发展演变和环流特征。结果表明:条件对称不稳定是大气稳定状态和条件不稳定状态之间的中间纽带,大气由稳定向不稳定或者由不稳定向稳定的演变均通过条件对称不稳定来实现;对流对称不稳定环流的形成与不稳定层的配置有关,当低层为条件不稳定而高层叠加深厚的条件对称不稳定时,对流对称不稳定环流低层出现垂直上升气流,高层出现范围较广的倾斜上升气流,对称不稳定能量释放产生中尺度云带。当低层和高层出现条件不稳定,中间呈条件对称不稳定或弱稳定度层结时,从低层到高层出现较深厚的垂直上升气流,湿重力不稳定能量的释放导致了云带的形成。
Using the results of a sensitivity numerical simulation, the evolution and circulation feature of convective-symmetric instability is studied in this paper. The conditional symmetry instability is the intermediate process between the stable and instable states of the atmosphere. The evolution of the atmosphere from the stable to unstable state or from unstable to stable state comes through two stages. The convective-symmetric instability circulation is related with the state and type of the instability. When the conditional instability lies in the lower level and conditional symmetric instability in the upper level, the circulation will have vertical updrafts in the lower level and slantwise updrafts in the upper level. The release of conditional symmetric instability gives rise to a mesoscale rain belt. When the conditional symmetric instability lies in the middle level and conditional instability in the lower and upper levels, the circulation will have updrafts through the total column of the atmosphere. The release of conditional instability gives rise to a mesoscale rain belt.
出处
《热带气象学报》
CSCD
北大核心
2006年第3期253-258,共6页
Journal of Tropical Meteorology
基金
国家自然科学基金项目(项目编号:40175012)
关键词
对流对称不稳定
发展演变
环流特征
convective-symmetric instability
evolution
circulation feature
