Nonmigrating tidal signatures in the magnitude and the inter-hemispheric asymmetry of the equatorial ionization anomaly
Nonmigrating tidal signatures in the magnitude and the inter-hemispheric asymmetry of the equatorial ionization anomaly
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DOI：
10.1088/1742-6596/446/1/012019
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
C. Xiong;H. Lühr
中科院分区：
文献类型：
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作者：
C. Xiong;H. Lühr
基于 CHAMP 和 GRACE 卫星九年的观测，本研究对赤道电离异常 (EIA) 的潮汐特征和半球间不对称性进行了研究。 EIA震级参数在8月和12月左右分别显示纵向波数4和3（WN4/WN3）模式，而对于不同的EIA参数，各种潮汐参数的贡献是不同的。对于波峰波谷比 (CTR)，在 8 月左右的几个月内，对 WN4 贡献的主要非迁移潮汐分量是 DE3，而在 12 月至日左右的几个月中，静止行星波 SPW3 在对 WN3 的贡献中与 DE2 的作用相当。对于 EIA 磁通管的顶点高度指数 (ApexHC)，静止行星波 SPW4/SPW3 超过 DE3/DE2 的振幅，DE3/DE2 在引起纵向 WN4/WN3 模式中起主导作用。在 12 月至日前后的几个月中，SW3 潮汐在 CTR 和 ApexHC 中都很突出。 SW3 显示出对太阳通量水平的强烈依赖性，而几乎不依赖于磁活动。对于 EIA 半球间不对称，只能看到 WN1 和 WN2 纵向图案。在六月至日期间，这种模式可以用静止行星波 SPW1 和 SPW2 来解释。相反，12 月至日前后的月份纵向特征表现出一些当地时间的演变，特别是日间非迁移潮 D0 起主导作用。
Based on nine years of observations from the satellites CHAMP and GRACE the tidal signatures in the magnitude and the inter-hemisphere asymmetry of the equatorial ionization anomaly (EIA) have been investigated in this study. The EIA magnitude parameters show longitudinal wavenumber 4 and 3 (WN4/WN3) patterns during the months around August and December, respectively, while for different EIA parameters the contributions of the various tidal parameters are different. For the crest-to-trough ratio (CTR) the dominating nonmigrating tidal component contributing to WN4 is DE3 during the months around August, while during the months around December solstice the stationary planetary wave, SPW3, takes a comparable role to DE2 in contributing to WN3. For the apex height index (ApexHC) of the EIA fluxtube the stationary planetary waves, SPW4/SPW3, exceed the amplitudes of DE3/DE2 taking the leading role in causing the longitudinal WN4/WN3 patterns. During the months around December solstice the SW3 tide is prominent in both CTR and ApexHC. SW3 shows a strong dependence on the sola flux level, while it is hardly dependent on magnetic activity. For the EIA interhemispheric asymmetry only WN1 and WN2 longitudinal patterns can be seen. During June solstice months the pattern can be explained by stationary planetary waves SPW1 and SPW2. Conversely, around December solstice months longitudinal features exhibit some local time evolution, in particular the diurnal nonmigrating tide D0 takes the leading role.