Unraveling the Ionospheric Storm-Enhanced Density Formation, Interhemispheric Asymmetry and Role in Plasmaspheric Refilling Using GITM-SAMI3

Ionospheric density variations affect the propagation of radio waves, such as the Global Navigation Satellite System (GNSS) and over-the-horizon radar signals. Those effects are more prominent during active geomagnetic conditions under which important high-density structures develop. Storm-enhanced densities (SEDs) are one of those structures that mainly observed in the mid-latitudes and subauroral regions. Their formations are the outcome of complex interactions among diffusion, electric fields and neutral wind transport as well as thermospheric composition. In addition, the SED phenomenon can also be interhemispheric asymmetric (IHA) related to various factors, such as Universal Time (UT), seasons, and energy depositions. Besides their space weather impacts, SEDs extend to high altitude and connect with the plasmasphere as a potential source for plasmasphere density, further affecting plasmaspheric dynamics and wave-particle interactions there.

Our goal is to study the SED generation mechanisms and IHA under different storm conditions as well as the SED impacts on the plasmasphere by using the new coupled GITM-SAMI3 model. GITM is a 3D thermosphere-ionosphere spherical model providing realistic simulation with flexible resolution. SAMI3 is another comprehensive, physics-based global thermosphere-ionosphere-plasmasphere model. The coupled model overcomes the altitudinal limitation of GITM and provides the self-consistently calculated thermospheric information from GITM to SAMI3, which is expected to produce more realistic results of the SED and its interaction with the plasmasphere.