Impacts of Thunderstorm‐Generated Gravity Waves on the Ionosphere‐Thermosphere Using TIEGCM‐NG/MAGIC Simulations and Comparisons With GNSS TEC, ICON, and COSMIC‐2 Observations

We use the TIEGCM‐NG nudged by MAGIC gravity waves to study the impacts of a severe thunderstorm system, with a hundred tornado touchdowns, on the ionospheric and thermospheric disturbances. The generated waves induce a distinct concentric ring pattern on GNSS TIDs with horizontal scales of 150–400 km and phase speeds of 150–300 m/s, which is well simulated by the model. The waves show substantial vertical evolution in period, initially dominated by 0.5 hr at 200 km, shifting to 0.25 hr and with more higher‐frequency waves appearing at higher altitudes (∼400 km). The TADs reach amplitudes of 100 m/s, 60 m/s, 80 K, and 10% in horizontal winds, vertical wind, temperature, and relative neutral density, respectively. Significantly perturbations in electron density cause dramatic changes in its nighttime structure around 200 km and near the EIA crest. The concentric TIDs are also simulated in ion drifts and mapped from the Tornado region to the conjugate hemisphere likely due to neutral wind‐induced electric field perturbations. The waves manage to impact the ionosphere at altitudes of ICON and COSMIC‐2, which pass through the region of interest on a total of 8 separate orbits. In situ ion density observations from these spacecrafts reveal periodic fluctuations that frequently show good agreement with the TIEGCM‐NG simulation. The O+ fraction observations from ICON indicate that the density fluctuations are the result of vertical transport of the ions in this region, which could result from either direct forcing by neutral winds or electrodynamic coupling. Plain Language Summary The ubiquitous gravity waves (GWs) are often generated in the lower atmosphere of the Earth by activities associated with terrestrial weather and play an important role in transporting energy and momentum to the upper atmosphere. Transient fluctuations and coupling to plasma motions induced by GWs can cause significant disturbances to ionospheric scintillation, satellite orbits, and space infrastructure. In this work, we couple a neutral wave model to an ionosphere‐thermosphere model through a nudging technique, to simulate the lifecycle of a group of GW packets generated by a severe thunderstorm system over the US continent. The simulated wave characteristics match multi‐layer observations including those in the stratosphere (AIRS), F‐region (GNSS TEC), and topside of the ionosphere (COSMIC‐2, ICON), indicating the profound effect of vertical wave coupling. The waves not only cause sig