The proposal is designed to determine the influence of storm-time neutral winds on subauroral polarization streams (SAPS) flows in the magnetosphere-ionosphere-thermosphere (MIT) coupling system. SAPS…

This is a $403,176.52 grant awarded by NASA to the University of Colorado for a study on the influence of storm-time neutral winds on Subauroral Polarization Streams (SAPS) in the magnetosphere-ionosphere-thermosphere (MIT) coupling system. The research aims to identify, separate, and quantify the feedback effect of neutral wind-generated electric fields on SAPS electric fields, ring current pressures, and region 2 field-aligned currents in the subauroral ionosphere-inner magnetosphere. The study will combine observational data from NASA's THEMIS and Van Allen Probes missions with a physics-based coupled MIT model to address three key science questions related to SAPS penetration, neutral wind feedback, and impacts on region 2 currents and the plasmapause. This grant is part of NASA's Heliophysics program and is not associated with any set-aside designation.

The proposal is designed to determine the influence of storm-time neutral winds on subauroral polarization streams (SAPS) flows in the magnetosphere-ionosphere-thermosphere (MIT) coupling system. SAPS are fast sunward plasma flows and were observed recently by the NASA themis and van allen probes (VAP). Central objectives: the proposed study will identify, separate out, and quantify the feedback effect of the neutral wind-generated electric field onto the SAPS electric field, ring current pressures, and region 2 field-aligned currents (R2 facs) in the subauroral ionosphere-inner magnetosphere interaction processes. The proposed research will target specifically the following three science questions: Q1. When and where do SAPS penetrate equatorward of the R2 FAC, including into the plasmasphere? Is this penetration associated with disturbed neutral winds? Q2. How does the storm time neutral wind feedback on the SAPS electric field in this MIT coupling system, and what is its relative contribution? Q3. How does the wind-generated electric field impact the R2 facs via the ring current pressure distribution and impact the plasmapause location? Methods/techniques: these science questions will be addressed by combining and synthesizing resources from NASA themis, VAP, other components of our current expanded observation capabilities, and the state of the art physics based coupled MIT model (CTIPRCM) that has been developed in the PI's group by a previous NASA LWS grant. Perceived significance: the proposed study of MIT coupling effects on inner magnetospheric dynamics will advance the science goal of the heliophysics decadal survey: 2. Determine the dynamics and coupling of earth S magnetosphere, ionosphere, and atmosphere and their response to solar and terrestrial inputs. In particular, the science questions addressed in our proposal will improve the scientific understanding of the thermospheric influence on dynamical features in the MI coupling associated with SAPS.