Quasi‐biennial modulation of the semidiurnal tide in the upper mesosphere above Halley, Antarctica
Quasi‐biennial modulation of the semidiurnal tide in the upper mesosphere above Halley, Antarctica
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南极洲哈雷上层中层半日潮的准两年一次调制
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
M. Jarvis
中科院分区：
文献类型：
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作者：
R. Hibbins;P. Espy;M. Jarvis
我们提出了一个长期档案的水平风数据的分析来自流星风观测SuperDARN雷达在哈雷，南极洲（76°S，27°W）。观测到纬向风的12小时分量与气候平均值之间的系统性差异，显示了中层上部高纬半日潮准两年调制的证据。当赤道平流层10 hPa以上准两年振荡为西风时，观测到的潮汐振幅增强。当纬向波数1（S = 1）非迁移分量主导半日风场时，这种增强在夏季潮汐振幅中最大，并且与夏季中层上部行星波活动的增强一致。这些观测结果有力地支持了这样的假设，即在高纬度观测到的半日潮的S = 1分量是由于迁移的S = 2半日潮和准定常的S = 1行星波之间的非线性相互作用。
We present an analysis of a long‐term archive of horizontal wind data derived from meteor wind observations from a SuperDARN radar at Halley, Antarctica (76°S, 27°W). Systematic differences between the 12‐hour component in the meridional wind and the climatological mean are observed showing evidence of a quasi‐biennial modulation of the high‐latitude semidiurnal tide in the upper mesosphere. The amplitude of the observed tides is enhanced when the equatorial stratospheric quasi‐biennial oscillation above 10 hPa is westerly. This enhancement is greatest in the summertime tidal amplitudes when the zonal wavenumber one (S = 1) non‐migrating component dominates the semidiurnal wind field, and is coincident with an enhancement of the summertime planetary wave activity in the upper mesosphere. These observations strongly support the hypothesis that the S = 1 component of the semidiurnal tide observed at high latitudes is due to a non‐linear interaction between the migrating S = 2 semidiurnal tide and quasi‐stationary S = 1 planetary waves.