Responses of Mesosphere Temperature to the Geomagnetic Storms on 8 and 15 September 2003.

The impact of geomagnetic storms on the mesosphere temperature has been controversial and lacks direct observational evidence. The intricate chemical and physical processes in the mesosphere, combined with the scarcity of observations, pose challenges to achieving a thorough comprehension of storm‐induced turbulences in this region. Currently, some investigations have characterized temperature responses during geomagnetic storms and the focus has largely been on changes above mesopause (∼90 km). In this work, the responses of temperature in the mesosphere (75–95 km) to the storms on September 8 and 15, 2003 and its causes are studied using observations from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument onboard the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite. It is found that (a) temperature responses for the moderate storm on September 15 manifest as increases within the latitude range of 80°S to 65°S, with peak values decreasing from approximately 15 K to around 7 K as latitude decreases, while for the minor strom of September 8 temperature changes only occur at ∼80°S with peaks of 7 K and −10 K, (b) the temperature responses can be transmitted down to 76–81 km, depending on the latitude and storm magnitude, and (c) there are significant fluctuations in both ozone (exceed 45%) and atomic oxygen (exceed 90%) after storm onset, highly correlated with temperature temporal and spatial variations. We suggest that the increases in ozone caused by the increases in atomic oxygen concentrations are the major contributor to rising temperature. Plain Language Summary: Geomagnetic storms may have a non‐negligible effect on the atmospheric circulation, neutral temperature, winds, and composition of the mesosphere and lower thermosphere. However, there is a lack of understanding of the perturbations and its chemical and physical processes in the mesosphere during geomagnetic storms. In this paper, we analyze temperature, ozone, and atomic oxygen observations acquired from the SABER instrument aboard the TIMED satellite. Our work demonstrate that variations in mesosphere temperature occur at high latitudes and are correlated with the magnitude of the storm. Additionally, significant disturbances in ozone and atomic oxygen are observed from 80°S to 65°S latitude. We propose that the variations in mesosphere temperature at high latitudes are dominated to changes in ozone caused by the heightened concentrations of atomic oxygen. Key Points: Temperatures of the mesosphere observed by SABER have remarkable responses to the geomagnetic storms of 8 and 15 September 2003The mesosphere temperature variations occur at high latitudes and can be conveyed to 76–81 km, depending on the latitude and storm magnitudeOzone variations are responsible for the mesosphere temperature variations at high latitudes during storms [ABSTRACT FROM AUTHOR]