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：
10.5194/angeo-31-1115-2013
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发表时间：
2013-06
影响因子：
1.9
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
抽象的。根据CHAMP和GRACE卫星9年的观测资料，研究了赤道电离异常(EIA)的量级和半球间不对称性的潮汐特征。环评震级参数在8月和12月前后分别表现为纵向波数4和3(WN4/WN3)型，但对于不同的环评参数，各潮汐参数的贡献是不同的。对于峰谷比(CTR)，在8月前后对WN4贡献最大的非移动潮汐分量是DE3，而在12月至前后的月份中，定常行星波SPW3对WN3的贡献与DE2相当。对于EIA通量管的顶点高度指数(ApexHC)，定常行星波SPW4/SPW3超过了DE3/DE2的振幅，在产生纵向WN4/WN3型中起主导作用。在12月至前后的几个月里，CTR和ApexHC都出现了SW3潮。SW3对太阳通量水平有很强的依赖性，而对磁活动的依赖性很小。对于环评的半球间不对称性，只能看到WN1和WN2型纵向分布。在六月至日期间，这种模式可以用静止的行星波SPW1和SPW2来解释。相反，在12月至月前后，经向特征表现出一定的局地时间演变，特别是日非迁移潮D0起主导作用。
Abstract. 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 solar flux level, while it is hardly dependent on magnetic activity. For the EIA inter-hemispheric 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.