Study of the Mid‐Latitude Airglow Responses to Geomagnetic Storms Based on Long‐Term Observations in Japan With the TIMED Satellite and Ionosondes

Abstract Variations in nighttime airglow at mid‐latitudes during geomagnetic disturbances reflect the propagation of atmospheric and plasma disturbances from polar heating as well as local chemical processes. However, their detailed mechanisms remain unclear. In this study, we analyzed the responses of six nighttime airglow emissions to geomagnetic storms using data from airglow temperature photometers at three locations in Japan (Rikubetsu (43.5°N, 143.8°E), Shigaraki (34.8°N, 136.1°E), and Sata (31.0°N, 130.7°E)) over a long‐term period from January 2004 to October 2023. The emissions include the OH Meinel band, O 2 atmospheric band, O (557.7 nm), Na (589.3 nm) from the mesopause region, and O (630.0 and 777.4 nm) from the thermosphere. The main results show an increase in the intensity of the 557.7‐nm emission 2 days after geomagnetic storms in the mesopause region and an increase in the 630.0‐nm emission 1 day after storms in the thermosphere. Similar responses were observed in the O 2 atmospheric band (mesopause region) and the 777.4‐nm emission (thermosphere) to those of 557.7‐nm and 630.0‐nm emissions, respectively. No significant changes were found in the rotational temperatures of OH and O 2 . The SABER instrument onboard the TIMED satellite observed a post‐storm increase in the atomic oxygen mixing ratio at altitudes of 90–100 km. We suggest that this atomic oxygen increase contributed to the enhanced 557.7‐nm emission in the mesopause region. Ionosondes over Japan observed rise of ionospheric altitudes and enhancements of foF2 1 day after storms. We discuss their possible relation to the observed thermospheric 630.0‐nm emission enhancements.