A Modeling Study of the Responses of Mesosphere and Lower Thermosphere Winds to Geomagnetic Storms at Middle Latitudes
A Modeling Study of the Responses of Mesosphere and Lower Thermosphere Winds to Geomagnetic Storms at Middle Latitudes
复制标题
中纬度地区中层和低热层风对地磁暴响应的模拟研究
DOI：
10.1029/2019ja026533
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Jianyong Lu
中科院分区：
文献类型：
--
作者：
Jingyuan Li;Wenbin Wang;Jianyong Lu
对2002年4月17日风暴期间中纬度地区的热层电离层、中层电动力学环流模式（TIMEGCM）模拟结果进行了诊断分析，探讨了风暴期间中纬度地区中层和低热层风场变化的原因。在风暴的早期阶段，中纬度上层热层风的变化较大，且发生得早于MLT风的变化。水平风的变化引起向下的垂直风的变化，并将其传递到MLT区域。绝热加热和热平流与向下的垂直风导致MLT温度升高。由这些温度变化和科里奥利力产生的压力梯度然后在夜间驱动强烈的向赤道纬向风变化，这些风向低纬度扩展。动量平流很小。随着风暴的发展，增强的MLT温度产生向上的垂直风。这些向上的风导致温度下降，从而改变了MLT的水平风模式，并在高纬度地区造成向极风扰动。
Thermosphere Ionosphere Mesosphere Electrodynamics General Circulation Model (TIMEGCM) simulations are diagnostically analyzed to investigate the causes of mesosphere and lower thermosphere (MLT) wind changes at middle latitudes during the 17 April 2002 storm. In the early phase of the storm, middle‐latitude upper thermospheric wind changes are greater and occur earlier than MLT wind changes. The horizontal wind changes cause downward vertical wind changes, which are transmitted to the MLT region. Adiabatic heating and heat advection associated with downward vertical winds cause MLT temperature increases. The pressure gradient produced by these temperature changes and the Coriolis force then drive strong equatorward meridional wind changes at night, which expand toward lower latitudes. Momentum advection is minor. As the storm evolves, the enhanced MLT temperatures produce upward vertical winds. These upward winds then lead to a decreased temperature, which alters the MLT horizontal wind pattern and causes poleward wind disturbances at higher latitudes.