The quasi 2‐day wave observed in the polar mesosphere: Comparison of the characteristics observed at Tromsø and Poker Flat
The quasi 2‐day wave observed in the polar mesosphere: Comparison of the characteristics observed at Tromsø and Poker Flat
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极地中间层观测到的准2日波：特罗姆瑟和扑克平地观测到的特征比较
DOI：
10.1029/2002jd003221
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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：
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作者：
S. Nozawa;H. Iwahashi;A. Brekke;C. Hall;C. Meek;A. Manson;S. Oyama;Y. Murayama;R. Fujii
[1]利用1998年11月1日至2002年11月7日104年的风场资料，对特罗姆瑟（69.6°N，19.2°E）和扑克坪（65.2°，147.6°W）在70、76、82和88 km四个高度观测到的准2日波（Q2 DW）进行了比较。Q2 DW的特征，如季节变化、最大振幅周期的出现、纬向振幅与纬向振幅的比值、相位高度剖面的形状以及在扑克平原发现的4-10天速率的振幅调制，与Nozawa等人[2003]在特罗姆瑟发现的特征非常相似。两个地点的纬向分量和纬向分量的Q2 DW活动冬季高于夏季。长期变化（即，季节性变化）的Q2 DW被发现是类似的两个网站之间，而短期变化（即，在几天内）彼此不能很好地同步。两个部位之间的Q2 DW振幅比主要在0.5和2之间变化，并且对任何一个部位都没有明显的偏好。研究了两个站点的Q2 DW的相位差，发现在冬季76、82和88 km处以及夏季88 km处，类同相事件比类异相事件更频繁。这可以解释为，在极地上层中层，Q2 DW的纬向波数似乎是2或4，而不是3。这些结果表明，观测到的Q2 DW具有与Rossby重力波模式一致的特征，但Q2 DW的振幅和相位受本地源的影响很大。文中还讨论了观测到的Q2 DW是一个东移波的可能性。
[1] A comparison of the quasi 2-day wave (Q2DW) observed at Tromso (69.6°N, 19.2°E) and Poker Flat (65.2°, 147.6°W) is presented at four heights of 70, 76, 82, and 88 km using wind data taken for ∼4 years, from 1 November 1998 to 7 November 2002. The characteristics of the Q2DW such as seasonal variation, occurrence of period of maximum amplitude, ratio of meridional to zonal amplitudes, shape of altitude profile of phase, and modulation of amplitude at a 4–10 days rate found at Poker Flat are very similar to those found at Tromso reported by Nozawa et al. [2003]. The activity of the Q2DW is higher in winter than in summer for meridional and zonal components at the two sites. Long-term variation (i.e., seasonal variation) of the Q2DW is found to be similar between the two sites, while short-term variations (i.e., over several days) do not synchronize well with each other. The ratio of amplitudes of the Q2DW between the two sites varies mainly between 0.5 and 2, and there is no significant preference toward either site. Phase differences of Q2DWs between the two sites are examined, and it is found that in-phase-like events are more frequently seen than out-of-phase-like events at 76, 82, and 88 km in winter and at 88 km in summer. This can be interpreted to mean that the zonal wave number of the Q2DW appears to be 2 or 4 more often than 3 in the polar upper mesosphere. These results suggest that observed Q2DWs have features consistent with the Rossby gravity wave mode, but the amplitude and phase of the Q2DW are affected significantly by local sources. A possibility that the observed Q2DW is an eastward moving wave is also discussed.