| Name: Souvik Roy |
| Affiliation: University of California Los Angeles |
| Conference ID: ASI2026_1039 |
| Title: Role of Polar Outflows in the Storm-Time Magnetosphere: Results from Multifluid MHD Simulations |
| Abstract Type: Poster |
| Abstract Category: Sun, Solar System, Exoplanets, and Astrobiology |
| Author(s) and Co-Author(s) with Affiliation: Souvik Roy(University of California, Los Angeles - 90095, USA), Kareem Sorathia(Johns Hopkins University Applied Physics Laboratory, Laurel - 20723, USA), Anthony Sciola(Johns Hopkins University Applied Physics Laboratory, Laurel - 20723, USA), Savvas Raptis(Johns Hopkins University Applied Physics Laboratory, Laurel - 20723, USA), Roger Varney(University of California, Los Angeles - 90095, USA) |
| Abstract: Ionospheric outflows are an important internal source of plasma for the magnetosphere, especially during geomagnetic storms, and they can strongly influence the storm-time plasmasheet. However, the relative roles of ionospheric plasma and solar wind plasma, and the pathways through which these different populations enter and populate the plasmasheet, are still not fully understood. Addressing this problem requires self-consistent global modeling together with physically meaningful diagnostics. In this study, we use the Multiscale Atmosphere–Geospace Environment (MAGE) framework with the multifluid GAMERA global MHD model to simulate a coupled geospace system under storm conditions. The storm is driven by an idealized ICME flux rope at four differenent seasons throughout a year. The model includes separate ionospheric outflow sources from the northern and southern hemispheres and explicitly tracks their transport into the magnetosphere. To examine the plasmasheet response, we develop a physics-based diagnostic that identifies the plasmasheet region using magnetic topology along with plasma properties such as plasma beta and density. This approach allows us to isolate the plasmasheet and quantify its composition in a consistent manner throughout the storm. We focus on how outflowing ion populations originating from different sources contribute to the density and composition of the plasmasheet, and how these contributions change with dipole tilt and storm phase. The results show that ionospheric and solar wind plasma interact in a highly dynamic way, with their relative importance varying over the course of the storm. These findings provide new insight into the role of ionospheric outflows in shaping the structure and evolution of the storm-time magnetospheric plasma environment. |
