摘要：
利用Andes(30.3.S,70.7.W)流星雷达2010年1月1日～2014年3月21日的观测数据,研究了中间层和低热层(mesosphere and lower thermosphere,MET)区域水平背景风场、周日潮汐以及周日潮汐与行星波之间的相互作用;并与模式结果进行了比较.多年观测结果表明,在80～ 100 km高度,月平均经向风场在5～8月份是南向风,在10 ～2月份是北向风,其变化范围在-11 ～13 m·s-1间,明显比HWM-07模式计算的月平均值-4～6 m·s-1范围大;观测的月平均纬向风场全年主要以东向风为主,只有少数月份的少数高度为西向风,风速范围为-14 ～32 m·s-1,比模式计算的月平均值-20～37 m·s-1变化范围略小.观测和GSWM-00模式给出的周日潮汐月平均振幅时空分布都呈现双峰结构,观测的最大峰值出现在3月份,经向和纬向分量月平均振幅峰值分别为51 m·s-1和44 m·s-1,次峰出现在9月份,经向和纬向分量月平均振幅次峰值分别为40～37 m·s-1.模式计算的经向和纬向月平均振幅峰值约为观测值的2倍,且峰值出现的时间也比观测值晚1～2个月.这些研究结果表明,模式对南半球月平均风场和周日潮汐的描述,与实际观测值间存在明显差异,还需要加强对南半球的观测研究,来不断提高和完善目前的模式.此外,我们的研究显示,在MLT区域,由于周日潮汐和行星波都比较强,周日潮汐能与不同周期的行星波相互作用,产生新的谱成分,从而导致潮汐发生短期变化.%Based on the data measured by meteor radar at Andes (30.3° S,70.7°W)from 1 Jan 2010 to 21 march 2014,horizontal background wind,diurnal tide and interactions between diurnal tide and planetary waves in the mesosphere and lower thermosphere(MLT) are studied and compared with the results of models.The observations show that at 80 ～ 100 km,the monthly mean meridional wind is southward from May to August and northward from October to February,and its value is in the range of-11 ～ 13 m· s-1,which is obviously larger than that of -4 ～6 m· s-1 derived from HWM-07.The observed monthly meanzonal wind usually is eastward all the year,except only few months at several altitudes,and its variational range of about-14 ～ 32 m· s-1 is slightly smaller than that of-20 ～ 37 m· s-1 from HWM-07.Both the observations and GSWM-00 show that the diurnal tide exhibits two peaks in the time-height section of its monthly mean amplitudes.The maximum values of the monthly meanmeridional and zonal amplitudes observed by meteor radar are about 51 m· s-1 and 44 m· s-1 in March,respectively,and the second maxima are about 40 ～ 37 m· s-1 in September,respectively.The peak values of the monthly mean meridional and zonal amplitudes from GSWM-00 are almost twice as large as those from meteor radar,with 1 ～ 2 month lag.The results indicate that more observational investigations in the Southern Hemisphere are required to improve the models since there are some differences inthe background wind field and the diurnal tide between the models and the observations.Besides,our analysis shows that owing to their large amplitudes,the diurnal tide and planetary waves with different periods can nonlinearly interact to generate the new spectral components in the MLT,which leads to a short-term tidal variability.
