基于北京流星雷达的MLT区域大气风场研究

Research on atmospheric wind field in MLT region based on Beijing meteor radar

摘要:

探测和研究大气风场是认知中高层大气结构的最重要的手段之一，其中流星雷达是一种非常好的观测大气风场的手段。为了更好地了解中纬中间层-低热层(MLT)区域大气风场的特征，本文利用2016年北京流星雷达反演的风场数据进行研究。首先研究了大气平均风场随时间和高度的变化特征，得出1~3月北京上空MLT区域的纬向风均以西风为主，经向风南风与北风交替显著，但仍以北风为主导的结论。继而对于90 km处的大气潮汐波进行研究，通过Lomb-Scargle功率谱方法和谐波拟合得出了大气潮汐随时间的变动规律，即中纬地区大气水平风场受到的潮汐波影响以半日潮汐为主、周日潮汐次之。

Abstract:

Detecting and studying the atmospheric wind field is one of the most important means of understanding the structure of the middle and upper atmosphere, among which meteor radar is a very good means of observing the atmospheric wind field. In order to better understand the characteristics of the atmospheric wind field in the mid-latitude Mesosphere and Lower Thermosphere(MLT) region, this paper uses the 2016 Beijing Meteor Radar inverted wind field data for research. Firstly, the change characteristics of the atmospheric mean wind field with time and height are studied, it is concluded that the zonal wind in the MLT area over Beijing from January to March is dominated by west wind, and for the meridional wind, south wind and north wind alternate significantly, but the north wind is still dominant. And then the atmospheric tidal wave at 90 km is studied. The law of atmospheric tide changes with time is obtained through the Lomb-Scargle power spectrum method and harmonic fitting. We found that the influence of tidal waves on the atmospheric horizontal wind field in the mid-latitude is mainly the half-day tide, followed by the day tide.