Comment on acp-2022-534

Abstract

Based on the global COSMIC occultation data, the latitudinal dependence of the geomagnetic and solar activity effect on the sporadic-E (Es) layer is investigated. Statistical results demonstrate that the relationship between Es layer occurrence rate and geomagnetic activity shows no correlation in low geomagnetic latitudes, a negative correlation in middle geomagnetic latitudes, and a positive correlation in high geomagnetic latitudes. The decrease in Es layer occurrence rate during geomagnetic activity in middle geomagnetic latitudes may be due to the descending meteor rate caused by the atmospheric density change during the geomagnetic storm. While the increase in Es layer occurrence rate in high geomagnetic latitudes is mostly related to the ionospheric electric field change driven by the international magnetic field (IMF) embedded within the solar wind. Solar activity effect on the Es layer also presents latitudinal dependence, with negative correlation in low and middle geomagnetic latitudes and positive correlation in high geomagnetic latitudes. The negative correlation may be owing to the negative correlation between meteor rate and solar activity revealed by many previous studies. The positive correlation in high geomagnetic latitudes is mostly related to the enhanced IMF during solar maximum.