斜压大气中任意频率惯性重力内波不稳定的判据  

Unstable Criterion about the Internal Inertial Gravity Wave with Any Frequency in the Baroclinic Atmosphere

作　　者：吴洪[1] 牛宁[1] 豆京华 WU Hong;NIU Ning;DOU Jinghua(China Meteorological Administration Training Center,Beijing 100081,China;Hebei Sub-center of China Meteorological Adminis-tration Training Center,Baoding 071000,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河北分院,河北保定071000

出　　处：《成都信息工程大学学报》2023年第6期728-733,共6页Journal of Chengdu University of Information Technology

基　　金：北京市自然科学基金资助项目(8212026)。

摘　　要：为分析斜压大气中任意频率惯性重力内波的稳定性,利用非静力平衡的Boussinesq近似的方程组和正交模方法,着重对波动不稳定的充分条件(即判据)进行讨论。主要结果表明:当基流随高度增大时,波动不稳定的必要条件是波动的等位相线向北倾斜;当基流随高度减小时,波动不稳定的必要条件是波动的等位相线向南倾斜。当大气为层结稳定时,波动不稳定的充分条件即判据是环境大气不但满足S^(4)-N^(2)F^(2)>0,且波动等位相面的倾斜率必须位于S^(2)-√S^(4)-N^(2)F^(2)/ N^(2)与S^(2)+√S^(4)-N^(2)F^(2)/N^(2)之间。对于层结稳定、惯性稳定的环境大气,若S^(4)>N^(2)F^(2),当环境大气的基流随高度增大时,S^(2)-√S^(4)-N^(2)F^(2)/N^(2)小于环境大气的等绝对动量面的倾斜率,S^(2)+√S^(4)-N^(2)F^(2)/N^(2)大于环境大气的等位温面的倾斜率。To analyze the stability of the internal inertial gravity wave with any frequency in the baroclinic atmosphere,this paper the sufficient condition of the instability about the wave is discussed with the emphasis on which is the unstable criterion,by the equations with Boussinesq approximation and non-hydrostatic balance and the method of normal mode.The main results show that when the basic flow increases with height,the necessary condition of the instability of the wave is that the slope of the constant phase line of the wave is slanted towards north.While the basic flow decreases with height,the necessary condition of the instability is that the wave is slant towards south.It is the sufficient condition of the instability about the internal inertial gravity wave that not only there is S^(4)-N^(2)F^(2)>0 about the atmosphere,but also the slope of the phase line of the internal inertial gravity wave is greater thanS^(2)-√S^(4)-N^(2)F^(2)/ N^(2)and less thanS^(2)+√S^(4)-N^(2)F^(2)/N^(2)in the baroclinic atmosphere when the atmosphere is the stable of stratification.If S^(4)>N^(2)F^(2) is greater than zero,theS^(2)-√S^(4)-N^(2)F^(2)/N^(2)is less than the slope of constant absolute momentum,and theS^(2)+√S^(4)-N^(2)F^(2)/N^(2)is greater than the slope of the equipotential temperature when there are the stable of stratification and inertial stable in the baroclinic atmosphere.

关 键 词：惯性重力内波 稳定性 对称不稳定 斜压大气 

分 类 号：P433[天文地球—大气科学及气象学]