估算大气重力波参数的垂直扰动廓线获取新方法  

A new method of obtaining perturbation vertical profiles in estimating the atmosphere gravity wave parameters

作　　者：程胡华[1] 钟中[1] 岑瑾[2] 邓少格[3] 

机构地区：[1]解放军理工大学气象海洋学院 [2]南京军区空军气象中心 [3]68028部队

出　　处：《物理学报》2012年第18期534-542,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:41130963;41175090)资助的课题~~

摘　　要：重力波是大气中最基本的动力过程,估算大气重力波参数是大气动力学理论研究的重要内容之一.针对常用曲线拟合方法获取大气垂直扰动廓线存在的固有缺陷,本文提出了估算大气重力波参数时垂直扰动廓线获取新方法.基于小波变换中的影响锥曲线性质,以影响锥曲线最大值作为区分背景场和扰动场的临界值,利用10阶ButterWorth高通滤波器对小于临界值的信号进行滤波得到扰动场.对实际大气过程高时空分辨率模拟纬向风和经向风垂直廓线的Morlet小波和Fourier功率谱分析表明,本文方法获得的扰动廓线中不再包含强背景场信息,且不会引入虚假波信号,克服了常用多阶曲线拟合方法的缺陷,利用该方法可以估算出合理的大气重力波参数.The gravity wave is the fundamental dynamic process in the atmosphere, and one of the important theoretical studies of atmosphere dynamics is to estimate the gravity wave parameters. Due to the inherent deficiency of the curve fitting method for the vertical perturbation profile （VPP）, a new method is proposed in obtaining the profile for estimating the reasonable gravity wave parameters. Based on the features of cone of influence in wavelet transformation and its maximum value, which is considered as the critical value for background profile and perturbation profile, the VPP is obtained with a 10th-order Butter Worth highpass filter for the signal with the magnitude less than the critical value. With the Morlet wavelet and Fourier power spectrum analyses for the numerically simulated zonal wind and meridional wind, it is found that there are neither distinct background signals nor false signal including in the VPPs, which overcomes the deficiency of curve fitting method. Therefore, the proposed method is excellent compared with the widely used curve fitting method in obtaining the VPPs, and the reasonable atmosphere gravity wave parameters could be estimated with the new method.

关 键 词：大气重力波参数 垂直扰动廓线 Morlet小波变换 Butter Worth滤波 

分 类 号：O354[理学—流体力学]