The seasonal behavior of high‐latitude thermospheric winds and ion velocities observed over one solar cycle
The seasonal behavior of high‐latitude thermospheric winds and ion velocities observed over one solar cycle
复制标题
DOI：
10.1029/96ja00360
复制
发表时间：
1996-07
影响因子：
--
通讯作者：
A. Aruliah;A. D. Farmer;D. Rees;U. Brändström
中科院分区：
文献类型：
--
作者：
A. Aruliah;A. D. Farmer;D. Rees;U. Brändström
在基律纳观测到的夜间热层风的季节性变化被发现明显依赖于太阳活动。特别令人感兴趣的是，尽管太阳辐射水平相似，但3月和9月的春分风之间存在很大差异。九月的春分风更像是十二月的冬至。三月春分的平均风向比九月大70%。热层或电离层模型模拟都没有预测到分点不对称的存在，它们假设分点基本上是相同的，并使用关于至点对称的强迫函数。在EISCAT测量的平均离子速度是在3月春分比9月在太阳极大，而匡威的是真实的在太阳极小。相比之下，三月春分夜间热层风是较大的太阳最大和太阳最小。此外，不对称性在太阳活动极大期更大。
The seasonal variation of nighttime thermospheric winds observed at Kiruna has been found to be significantly dependent on solar activity. Of particular interest is the observation that there is a large difference between the March and September equinox winds, despite similar levels of solar insolation. The September equinox winds are more December solstice-like. The average March equinox meridional winds are up to 70% larger than for September. The existence of an equinoctial asymmetry has not been predicted by either thermospheric or ionospheric model simulations, which assume that the equinoxes are fundamentally the same, and use forcing functions which are symmetric about the solstices. The average ion velocities measured at EISCAT are larger during the March equinox than the September at solar maximum, while the converse is true at solar minimum. In contrast, the March equinox nighttime thermospheric winds are larger for both solar maximum and solar minimum. Furthermore, the asymmetry is greater at solar maximum.