Storm-time Magnetosphere-Ionosphere-Thermosphere coupling processes revealed by distributed observations and numerical simulation

Abstract:

Geomagnetic storm represents the largest form of geomagnetic disturbances and is caused by two major interplanetary disturbance structures, i.e., interplanetary coronal mass ejection (ICME) and Corotating Interaction Region/High- speed stream (CIR/HSS). The ionospheric and thermospheric responses to the geomagnetic storms are of long-standing interest. One prominent phenomenon generated during storms is the ionospheric storm associated with strong disturbances in the plasma density and total electron content (TEC). The negative storm is generally believed to be due to thermospheric composition change. In contrast, the positive storm has been associated with a few different mechanisms, including neutral composition change, equatorward winds, eastward electric fields, and advection of high-density plasma. The key question is their relative importance under different interplanetary drivers. We use a systems science approach that can take into account the coupling among the different regions in the near-Earth space system and take advantage of the synergies between advanced numerical models, i.e., Space Weather Modeling Framework (SWMF), and distributed arrays of observations and images. Multi-instruments, such as GNSS receivers, AMPERE, GUVI, and ground-based radars, are analyzed to obtain insights into the nature of storm-time MIT coupling processes.