The influence of nonmigrating tides on the longitudinal variation of the equatorial electrojet
The influence of nonmigrating tides on the longitudinal variation of the equatorial electrojet
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DOI：
10.1029/2008ja013064
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发表时间：
2008-08
影响因子：
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通讯作者：
H. Lühr;M. Rother;K. Häusler;P. Alken;S. Maus
中科院分区：
文献类型：
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作者：
H. Lühr;M. Rother;K. Häusler;P. Alken;S. Maus
[1]由Orsted、CHAMP和SAC-C卫星测量得到的赤道电喷流EEJM-1的气候模式为详细研究海流强度的纵向变化提供了机会。这项研究特别强调了非迁移潮的影响。我们发现，波数为-3的日向东传播模DE3的影响尤为强烈。在极轨卫星观测中，DE3潮汐信号呈现出一个四峰的纵向结构。我们在分析中特别强调将DE3的贡献与其他对卫星数据中的波数-4结构作出贡献的来源分开。EEJ中的DE3信号的幅度不仅在春分季节达到峰值，而且在6月至日前后也很强。当观察EEJ强度的调制时，在4月至9月的几个月中，DE3约占25%。因此，它是纵向变化的主要原因。在12月至月期间，DE3的影响可以忽略不计。在去掉DE3影响后的冬至季节，出现了次三峰的经向型。然而，从现有的数据来看，尚不清楚这种模式是否与任何潮汐驱动因素有关。
[1] The climatological model of the equatorial electrojet, EEJM-1, derived from Orsted, CHAMP and SAC-C satellite measurements provides the opportunity to investigate the longitudinal variation of the current strength in detail. Special emphasis is put in this study on the effect of nonmigrating tides. We have found that the influence of the diurnal eastward-propagating mode with wavenumber-3, DE3, is particularly strong. In polar orbiting satellite observations the DE3 tidal signal appears as a four-peaked longitudinal structure. We have put special emphasis in our analysis to isolate the DE3 contribution from other sources contributing to the wavenumber-4 structure in satellite data. The amplitude of the DE3 signature in the EEJ not only peaks during equinox seasons, but is also strong around the June solstice. When looking at the modulation of the EEJ intensity the DE3 accounts for about 25% during the months of April through September. It is thus the dominant cause for longitudinal variations. During December solstice months the influence of DE3 is negligible. A secondary three-peaked longitudinal pattern emerges during solstice seasons when the DE3 influence is removed. From the data available it is, however, not clear whether this pattern is related to any tidal drivers.