基于气块法的对称不稳定探究  

Research on the Symmetric Instability Based on the Parcel Method

作　　者：吴洪[1] 齐道日娜 姜晓飞 徐丽娅[2] 任志杰 章丽娜[1] Wu Hong;Chyi Dorina;Jiang Xiaofei;Xu Liya;Ren Zhijie;Zhang Lina(China Meteorological Administration Training Center,Beijing 100081,China;Hubei Sub-center of China Meteorological Administration Training Center,Wuhan 430074,China;Liaoning Sub-center of China Meteorological Administration Training Center,Shenyang 110166,China)

机构地区：[1]中国气象局气象干部培训学院,北京100081 [2]中国气象局气象干部培训学院湖北分院,武汉430074 [3]中国气象局气象干部培训学院辽宁分院,沈阳110166

出　　处：《气象与环境科学》2023年第4期68-74,共7页Meteorological and Environmental Sciences

基　　金：北京市自然科学基金项目(8212026)。

摘　　要：采用“气块法”,分析斜压大气中对称不稳定判据,结果表明:在斜压大气中,斜升气流的不稳定,不同于经典的惯性不稳定、静力不稳定。对称不稳定的必要条件是等熵面的倾斜度大于等绝对动量面的倾斜度,其判据不仅与环境大气的等熵面、等绝对动量面之间的倾斜差异分布有关,还与斜升气块的路径斜率有关;斜升气流的倾斜度小于等绝对动量面或大于等熵面的倾斜度,仍有可能发生对称不稳定。在饱和湿斜压大气中,存在关于条件对称不稳定的类似结论,但判据比对称不稳定的复杂得多。The symmetric instability criterion is derived and discussed in the baroclinic atmosphere by the parcel method.The main results show that the instability of the slantwise airflow is different from the classical static instability or the inertial instability in the baroclinic atmosphere.The necessary condition for the symmetric instability is the slope of isentropic surface is greater than the slope of constant absolute momentum surface.Its criterion is related not only to the difference in the slopes of isentropic surface and constant absolute momentum surface in the ambient atmosphere,but also to the path slope of parcel going slantwise.Symmetric instability is possible to occur when the slope of the slantwise airflow is less than that of constant absolute momentum surface,or greater than that of isentropic surface.In the saturated wet baroclinic atmosphere,there are analogous conclusions about the conditional symmetric instability,but the criteria are much more complex than those for symmetric instability.

关 键 词：对称不稳定 条件对称不稳定 气块法 判据 

分 类 号：P433[天文地球—大气科学及气象学]