临近空间大气扰动风场的探测与分析

目的深入了解掌握临近空间大气风场的扰动状态,给临近空间飞行器的精确入轨、有效运行提供可靠的环境信息。方法用昆明站(25.6°N,103.8°E)临近空间观测平台中的MF雷达开展临近空间大气风场扰动观测。基于谐波拟合方法得到昆明地区2008年8月至2010年8月期间的周日和半日潮汐分量及背景风场,分析昆明地区临近空间80~100 km之间潮汐波动的变化特征。结果周日潮汐振幅具有明显的年变化和半年变化,最大值均出现在10月份和3月份的86~92 km高度范围内,同时第一年度的潮汐幅度明显强于第二年度,类似准两年变化。纬向半日潮汐的变化特征不是非常明显,而经向半日潮汐在88~94 km之间具有年变化,在其他高度处则出现多个峰值。结论潮汐相位的变化结果表明潮汐的下行传播,潮汐振幅的高度变化符合先增大后减小的特征,呈现胞状结构。

Wind-oscillation Measurement and Study in Near Space

Objective To understand variations of oscillation wind and provide exact environmental status for precision entering and running of aerocraft in near space. Methods The experiments on wind field turbulence were performed at Kunming station (25.6°N, 103.8°E) with Medium frequency radar (MF radar) in the near space observation platform. Based on data on diurnal and semidiurnal tide component and background wind field from Kunming from August 2008 to August 2010 with harmonic fitting method, characteristics of tide fluctuation in 80~100 km of near space in Kunming were analyzed. Results The variations periods of diurnal tide behaved annually and semiannually, although the amplitude of tidal in the first year was larger than that in the second year, which may be thought as quasi-biennial oscillation. The maximum values always occurred in October and March at 86~92 km. But the zonal semidiurnal tidal component has no this feature, at least not obviously. The case became complicated in meridional semidiurnal tidal that annual variation only dominated at 88~94 km region; and several peak values occurred at other height. Conclusion Changes of tide phase show the downward transmission of tide. The height change of tide meets the feature of increasing with height and then decreasing. It shows a cystiform structure.