Comment on “Evidence of Potential Thermospheric Overcooling During the May 2024 Geomagnetic Superstorm” by Kumar Ranjan et al.

Abstract The post‐storm neutral density ρ decrease (when it takes place) cannot be prescribed to a decrease in neutral temperature because this contradicts the observed negative foF 2 deviations normally observed during the recovery storm phase. Neutral temperature decrease also contradicts empirical (based on observations) thermospheric models such as MSISE00. The post‐storm neutral density decrease is due to a decrease in the atomic oxygen abundance during the recovery storm phase. The increase in atomic oxygen along with elevated storm‐time neutral temperature prevents the post‐storm neutral density decrease in winter. The observed rarity of the post‐storm ρ decrease is due to the interplay between the storm‐time decrease in atomic oxygen abundance and the increase in neutral temperature. The two processes work simultaneously in opposite directions during magnetic storms, compensating each other to a great extent. Therefore, the post‐storm neutral density decrease is not related to the NO overcooling but can be explained in the framework of the F 2 ‐layer storm mechanism.