Poststorm Thermospheric NO Overcooling?. Issue 1 (14th January 2020) - Mikhailov, Andrey V.
Key Points: The existing F 2 ‐layer storm mechanism is sufficient to explain the observed poststorm decrease in neutral gas density Storm‐induced atomic oxygen variation is the controlling process There is no need to attract a new "poststorm NO overcooling" concept Abstract: A mechanism of the neutral gas density decrease at middle latitudes during the recovery storm phase is discussed. The recently proposed method to retrieve thermospheric parameters from ionospheric observations is used for the analysis of equinoctial, summer, and winter severe magnetic storms. CHAllenging Minisatellite Payload and Swarm neutral gas density observations are used for a comparison. It is shown that storm‐induced atomic oxygen variation is the controlling process. Well‐known F 2 ‐layer storm morphology and the poststorm decrease of neutral gas density reflect the same storm‐induced variations of atomic oxygen abundance in the upper atmosphere. There is no need to attract a new "poststorm NO overcooling" concept to explain the decrease of neutral gas density.