A Numerical Study of the Equatorial Wind Jet Response to the X2.2 Solar Flare on 6 September 2017

Abstract

Using paired Thermosphere–Ionosphere–Electrodynamics General Circulation Model (TIEGCM) simulations, we investigated the response of the equatorial thermospheric zonal wind jet to the X2.2 solar flare that peaked at 09:10 UT on 6 September 2017. The simulations show enhanced morning‐side westward and evening‐side eastward winds. The westward wind disturbances during the X2.2 flare reached their largest magnitude at 11:49 UT, 2 h 39 min after the flare peak at 09:10 UT. At this time, the morning‐side and evening‐side zonal wind differences are −18.83 and 26.96 m/s, respectively. At the magnetic equator, the neutral‐temperature and electron‐density differences reach maxima of 97.30K and 3.00 × 10 ¹¹  m ⁻³ , respectively. The time‐integrated pressure‐gradient term is westward in the morning sector and eastward in the evening sector. Vertical viscosity opposes the morning westward response, whereas ion drag opposes the evening eastward response. In the evening sector, the viscosity difference is eastward and reinforces the pressure‐gradient forcing.