Solar dependence of equatorial F-region irregularities observed by COSMIC radio occultations
Solar dependence of equatorial F-region irregularities observed by COSMIC radio occultations
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COSMIC 射电掩星观测到的赤道 F 区不规则性的太阳依赖性
DOI：
10.1029/2018ja025936
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Tian Mao
中科院分区：
文献类型：
--
作者：
Tao Yu;Yasunobu Miyoshi;Chunliang Xia;Xiaomin Zuo;Xiangxiang Yan;Na Yang;Yangyi Sun;Xinan Yue;Tian Mao
采用改进的掩星反演方法，利用COSMIC卫星观测的大量S4指数剖面资料，研究了2007 - 2017年全球赤道区不规则性（EFIs）的太阳周期变化。这些完整的太阳活动周期数据表明，太阳活动对EFI的发生率和高度的影响是显著和复杂的。随着太阳活动的增加，在更高的高度（大于500 km），EFI的发生率增加。高海拔EFIs的平均高度和高度标准差（σh）对太阳活动的依赖性不明显。另一方面，在整个高度（150 - 800 km）上，EFI的发生率与太阳活动没有明显的关系。的 全高度的σ霍夫电场强度随太阳活动的增加而增加。此外，EFI的发生率对太阳活动的依赖性在春分点最强，冬季较弱，夏季最弱。电场和相应的季节变化可以解释EFI的发生和高度随太阳活动的变化，并且低空EFI似乎与大气重力波相关的种子有关。
With an improved method for retrieving the equatorialFregion irregularities (EFIs) from radio occultation measurements, a huge amount of S4 index profiles from Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) satellites is employed to study the solar cycle variation of global EFIs during the period of 2007 to 2017. This full solar cycle data show that impacts of the solar activity on the occurrence rates and heights of EFIs are notable and complex. The occurrence rates of EFIs at higher altitude (greater than 500 km) increase with increasing the solar activity. The mean heights ( ) and heights standard deviation (σh) of EFIs at higher altitudes do not show clearly the solar activity dependence. On the other hand, the occurrence rates of EFIs at entire altitudes (from 150 to 800 km) do not have clear relation with the solar activity. The and σhof EFIs at entire altitudes increase with increasing the solar activity. Moreover, the dependence of the occurrence rates of EFIs on the solar activity are the strongest in the equinoxes, weaker in winter and weakest in summer. The electric fields and corresponding seasonal variation can account for the EFIs occurrence and height variation versus solar activities, and the EFIs at low altitudes seem to be related to theseedassociated with atmospheric gravity wave.