Analysis of Mesoscale Neutral Wind Structures in the High-Latitude F-Region During Geomagnetic Storms

Neutral winds in the high-latitude F-region play a fundamental role in ionosphere–thermosphere (IT) coupling during geomagnetic storms by redistributing energy and momentum through ion-neutral interactions. However, the spatial and temporal evolution of mesoscale neutral wind structures remains poorly understood because most previous observations relied on single-point measurements. In this study, we investigate mesoscale horizontal and vertical neutral wind structures using tristatic observations from Scanning Doppler Imagers (SDIs) in Alaska combined with Poker Flat Incoherent Scatter Radar (PFISR), Super Dual Auroral Radar Network (SuperDARN), and all-sky imagers (ASIs). Using storm-time events (SYM-H < -30 nT), we examine the spatial gradients, divergence, and vorticity of reconstructed winds and compare them with auroral morphology, plasma convection, Joule heating, and ion-neutral coupling time scales. Storm-to-storm comparisons further show that similar geomagnetic storms can produce substantially different neutral wind structures, highlighting the importance of localized heating and mesoscale ionospheric dynamics in controlling thermospheric responses.