Ionospheric Variability during the 2020–2021 SSW: COSMIC-2 Observations and WACCM-X Simulations

Variability in the ionosphere during 2020–2021 sudden stratospheric warming (SSW) is investigated using a combination of Constellation Observing System for Meteorology, Ionosphere, and Climate-2 (COSMIC-2) observations Whole Atmosphere Community Climate Model with thermosphere–ionosphere eXtension (WACCM-X) simulations. The unprecedented spatial–temporal sampling low latitude afforded by COSMIC-2 enables investigating short-term (<5 days) variability SSW event. reveal reduction diurnal zonal mean total electron content (ITEC) reduced amplitude variation SSW. Enhanced ITEC amplitudes semidiurnal solar lunar migrating tides westward propagating tide wavenumber 3 are also observed. WACCM-X simulations demonstrate that these variations driven stratosphere–mesosphere results show impact on state, diurnal, ionosphere, as well capabilities mission to observe meteorological lower atmosphere.