摘要
利用德国 SOUSY VHF雷达在中间层高度上 6天的观测数据 ,研究了夏季极区中间层大气潮汐和水平风的变化特征。动态谱分析表明 ,半日潮是极区夏季中间层高度上占支配地位的波动 ;周日潮通常较弱 ,偶尔也会增长到与半日潮相当的强度 ;1 /8cph频率附近偶尔出现较强的谱峰 ,但持续时间更短。潮汐谱峰对应的频率一般与其定义值有偏离 ,说明它们经常处在被扰动的状态。在相差 2 .7km的两个高度上纬向和经向平均风的时间变化各自显示出较强的相似性 ,但是两者的时间变化倾向完全不同 ,反映了平均风变化的各向异性。每种潮汐在纬向和经向风中的谱峰对应的频率一般不相同 ,其水平扰动速度矢量端点随时间变化的轨迹一般也不再是闭合的椭圆 ,但仍保持顺时针方向旋转的特征。
Data obtained from the mobile SOUSY VHF radar at and φya /Norway (69°N,16°E) during the MAC/SINE campaign in summer l987 have been used to study the variability of tides and mean wind in the polar mesosphere. It is shown that the spectral peak corresponding to the semidiurnal tide dominates and persists almost uninterruptedly in time. The spectral peak corresponding to the diurnal tide is usually secondary and interrupted in time. Occasionally it enhances to an intensity comparable to that of the semidiurnal tide. The terdiurnal tide rarely presents a prominent spectral peak. The frequency corresponding to each tidal component often shows a deviation from its definition value. This likely represents a temporary or disturbed state. The time variations in either of the zonal and meridional mean winds for two heights with 2.7km distance show a considerable similarity, but their respective variation trends are different, indicating an anisotropy in the variability of the horizontal mean wind. Since the frequency values of each tidal component in the zonal and meridional winds are different, the hodograph of its wind vector with respect to time is no longer a close ellipse, but still has a clockwise rotation.
出处
《电波科学学报》
EI
CSCD
2000年第4期415-422,共8页
Chinese Journal of Radio Science
基金
国家杰出青年科学基金!4 96 2 5 40 7)
国家基金委"九五"重大项目!(4 9990 45 0 )
