Nitric Oxide cooling emission during geomagnetic storm: Case studies

The Nitric Oxide (NO) emission at 5.3 µm is the dominating thermospheric coolant in the altitude above ∼135 km. It effectively regulates the thermospheric temperature during space weather events. We studied the diurnal response of the Nitric Oxide at 5.3 µm emission to the geomagnetic storms of different intensities by using the NO emission data from the Sounding of Atmosphere using Broadband Emission Radiometry (SABER) instrument onboard NASA’s Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED) satellite. We selected eight CME-driven geomagnetic storms with |SYM-H| index ranging from 0 to 500 nT. One of the storms that occurred during 19-22 November 2003 is investigated in details. Other events are used for comparison. The NO flux and the NO power during different phases of the geomagnetic storms are calculated with 24 hours-time bins from the storm’s onset. The NO cooling and the cooling power are always higher during the daytime. Although the NO cooling flux and the cooling power increase with the storm intensity, they are not always higher during the stronger storms.