基于激光雷达实测和动力学仿真方法研究中间层顶垂直风扰动特性

Characteristics of Vertical Wind Perturbations in the Mesopause Region Based on Lidar Measurements and Dynamic Simulations

利用中国廊坊台站钠荧光多普勒激光雷达82h垂直风和水平风观测数据,统计得到中间层顶区域中存在10 m·s^(-1)量级的垂直风扰动和纬向风扰动,其中垂直风扰动远远超过平均风速为-0.015 m·s^(-1)的背景垂直风速.根据三维准单色重力波的极化关系和色散关系,对高中低三种频率重力波产生的垂直风扰动进行仿真,结果显示在满足短周期、大纬向风扰动条件下,高频重力波能够产生最大10m·s^(-1)量级的垂直风扰动,中频重力波能够产生10 m·s^(-1)以内的垂直风扰动,低频重力波能产生1m·s^(-1)以内的垂直风扰动.理论条件下准单色重力波能够产生10m·s^(-1)量级的垂直风扰动,钠激光雷达观测到的最大10m·s^(-1)量级的垂直风扰动真实存在.研究结果可对高层大气垂直风场探测、垂直风场模拟和重力波参数化提供依据.

A total of 82 h vertical wind and zonal wind profile data obtained by the Na fluorescence Doppler lidar at Langfang observatory of National Space Science Center, are used to simulate the vertical wind perturbations by using the polarization and dispersion relation of 3D quasi-monochromatic gravity wave. The observation data show that, including the measurement error, the perturbation magnitude of vertical wind and horizontal wind is about 10m·s^-1, and the perturbations of vertical wind are much larger than those of the background vertical wind. The mean background vertical wind is-0.015 m·s^-1. According to the different frequency, the gravity waves are divided into high,medium and low frequency waves. In the conditions of short period and large zonal wind perturbations, the vertical wind perturbations induced by high frequency gravity wave can reach 10m·s^-1, and the vertical wind perturbations induced by medium frequency gravity wave is less than 10m·s^-1, the vertical wind perturbations induced by low-frequency gravity waves is less than 1m·s^-1. The results indicate that the quasi-monochromatic gravity wave is capable of producing 10m·s^-1 vertical wind perturbations. In conclusion, 10m·s^-1 vertical wind perturbations measured by the Na fluorescence Doppler lidar at Langfang station agree with theoretical results. The study can provide theoretical basis for measuring and simulating of vertical wind, and gravity wave parameterizations.