Astafyeva E, Zakharenkova I, Huba J D, Doornbos E, van den IJssel J
Department of Planetology and Space Sciences, Institut de Physique du Globe de Paris, Paris Sorbonne Cité, University of Paris Diderot Paris France.
Plasma Physics Division, Naval Research Laboratory Washington DC USA.
J Geophys Res Space Phys. 2017 Nov;122(11):11716-11742. doi: 10.1002/2017JA024174. Epub 2017 Nov 20.
By using data from multiple instruments, we investigate ionospheric/thermospheric behavior during the period from 21 to 23 June 2015, when three interplanetary shocks (IS) of different intensities arrived at Earth. The first IS was registered at 16:45 UT on 21 June and caused ~50 nT increase in the SYM-H index. The second IS arrived at 5:45 UT on 22 June and induced an enhancement of the auroral/substorm activity that led to rapid increase of thermospheric neutral mass density and ionospheric vertical total electron content at high latitudes. Several hours later, topside electron content and electron density increased at low latitudes on the nightside. The third and much larger IS arrived at 18:30 UT on 22 June and initiated a major geomagnetic storm that lasted for many hours. The storm provoked significant effects in the thermosphere and ionosphere on both dayside and nightside. In the thermosphere, the dayside neutral mass density exceeded the quiet time levels by 300-500%, with stronger effects in the summer hemisphere. In the ionosphere, both positive and negative storm effects were observed on both dayside and nightside. We compared the ionospheric observations with simulations by the coupled Sami3 is Also a Model of the Ionosphere/Rice Convection Model (SAMI3/RCM) model. We find rather good agreement between the data and the model for the first phase of the storm, when the prompt penetration electric field (PPEF) was the principal driver. At the end of the storm main phase, when the ionospheric effects were, most likely, driven by a combination of PPEF and thermospheric winds, the modeling results agree less with the observations.
通过使用来自多种仪器的数据，我们研究了2015年6月21日至23日期间的电离层/热层行为，在此期间有三次不同强度的行星际激波（IS）抵达地球。第一次激波于协调世界时6月21日16:45被记录到，导致SYM-H指数增加了约50纳特斯拉。第二次激波于协调世界时6月22日5:45抵达，引发了极光/亚暴活动增强，导致高纬度热层中性质量密度和电离层垂直总电子含量迅速增加。数小时后，夜侧低纬度地区的电离层顶部电子含量和电子密度增加。第三次且强度大得多的激波于协调世界时6月22日18:30抵达，引发了一场持续数小时的 major 地磁风暴。这场风暴在白天和夜间的热层和电离层中都引发了显著影响。在热层中，白天的中性质量密度比平静时水平高出300 - 500%，在夏季半球影响更强。在电离层中，白天和夜间都观测到了正负两种风暴效应。我们将电离层观测数据与耦合的Sami3电离层模型/赖斯对流模型（SAMI3/RCM）模型的模拟结果进行了比较。我们发现，在风暴的第一阶段，当即时穿透电场（PPEF）是主要驱动因素时，数据与模型之间的一致性相当好。在风暴主阶段末期，当电离层效应很可能是由PPEF和热层风共同驱动时，模拟结果与观测结果的一致性较差。
