The quasi 2-day wave observed in the polar mesosphere
The quasi 2-day wave observed in the polar mesosphere
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极地中间层观测到的准2日波
DOI：
10.1029/2002jd002440
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发表时间：
2003
影响因子：
--
通讯作者：
R. Fujii
中科院分区：
文献类型：
--
作者：
S. Nozawa;S. Imaida;A. Brekke;C. Hall;A. Manson;C. Meek;S. Oyama;K. Dobashi;R. Fujii
我们利用1998年11月1日至2001年12月8日在特罗姆瑟（69.6°N, 19.2°E）获得的约37个月的中频雷达资料，研究了70 ~ 91 km高度的极地中间层准2日波（Q2DW）的特征。冬季（11 - 2月）的Q2DW活度高于夏季（5 - 8月）。振幅最大值冬季为~ 25 m s−1，夏季为~ 15 m s−1。在70到82公里之间，振幅在3年中接近冬至时达到最大值。在高度区域，经向振幅与纬向振幅的平均比值为~ 1.1-1.2。因此，对任何组件都没有明显的偏好。最大振幅周期的变化也进行了研究，45.2和54.9小时的周期比48.0和51.2小时的周期更频繁。但没有发现明显的季节变化趋势。此外，振幅以4-10天的速率调制。利用位于特罗姆瑟的中频雷达和EISCAT超高频雷达的同步观测数据，我们研究了1999年7月1日至9日期间Q2DW是否能够穿透到低层热层。经向和纬向分量均为~ 25 m s - 1， Q2DW的振幅在95 km高度达到最大值，周期为51.2 h。Q2DW在95 km以上减弱，但在经向分量中存在至108 km高度。在85 ~ 95 km的经向分量中，Q2DW和半日潮是周期分量中最强的。
[1] Using MF radar data obtained at Tromso (69.6°N, 19.2°E) for ∼37 months between 1 November 1998 and 8 December 2001, we have examined characteristics of the quasi 2-day wave (Q2DW) in the polar mesosphere in the height range from 70 to 91 km. The activity of the Q2DW is higher in winter months (November–February) than in summer months (May–August) over this height region. The maximum values of the amplitude are ∼25 m s−1 in winter and ∼15 m s−1 in summer. Between 70 and 82 km, the amplitude appears to maximize near winter solstice over the 3 years. The average ratio of meridional to zonal amplitudes is ∼1.1–1.2 over the height region. Thus, there is no significant preference towards either components. The variations of the periods of maximum amplitude are also examined, and periods with 45.2 and 54.9 hours occur more frequently than those with 48.0 and 51.2 hours. However, no clear seasonal trend of the variation of the period is found. In addition, the amplitude is modulated at 4–10 day rate. With simultaneous observational data from the MF radar and the EISCAT UHF radar colocated in Tromso, we have examined whether or not the Q2DW was able to penetrate to the lower thermosphere for the period of 1–9 July 1999. It is found that the amplitude of the Q2DW with period of 51.2 hours maximized at 95 km height with values of ∼25 m s−1 in both meridional and zonal components. The Q2DW was attenuated above 95 km, but it appears to survive up to 108 km height in the meridional component. Between 85 and 95 km for the meridional component during this 8-day interval, the Q2DW and semidiurnal tide were the strongest among the periodic components.