Abstract In this study we use the CHAMP wind observations from 2002 to 2004 to investigate features of mid-latitude thermospheric winds at low and high geomagnetic activity levels. The winds are observed between the geomagnetic latitudes 40o-50o north or south within an altitude range of 370 to 450 Km and averaged longitudinally. The low geomagnetic activity level wind generally leads eastward in both hemispheres for all the seasons. Maximum westward speeds going above 100 m/s are observed at all levels of geomagnetic activity. Most investigations on F-region parameters assume the equinoxes are fundamentally the same. A first time separation of Equinox season using CHAMP winds reveals equinoctial asymmetric behavior of the wind speed at the two levels considered. Interhemispheric asymmetry is clearly evident in the solstice seasons with local winds considered in each of the hemispheres. This is consistent with asymmetry in the amount of solar illumination received in each of the hemispheres and differences in the magnetic field strength at magnetically conjugate regions.

中文翻译：

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中纬度高热层纬向风的不对称行为和地磁依赖性

摘要 在这项研究中，我们使用 2002 年至 2004 年的 CHAMP 风观测来研究低地磁活动水平和高地磁活动水平下中纬度热层风的特征。在 370 至 450 公里的高度范围内，在地磁纬度 40 度至 50 度之间观察到风，并进行纵向平均。低地磁活动水平风在所有季节通常在两个半球都向东引导。在所有地磁活动水平上都观察到超过 100 m/s 的最大向西速度。大多数关于 F 区域参数的研究都假设分点基本相同。首次使用 CHAMP 风分离春分季节揭示了所考虑的两个级别的风速的春分不对称行为。在冬至季节，半球间的不对称性很明显，每个半球都考虑了局部风。这与每个半球接收到的太阳光照量的不对称性和磁性共轭区域磁场强度的差异是一致的。