Spatial and Temporal Variation Patterns of NO 5.3 µm Infrared Radiation during Two Consecutive Auroral Disturbances

Abstract

The variation in key parameters of the solar–terrestrial space during two consecutive auroral disturbances (the magnetic storm index, Dst index = −422 nT) that occurred during the 18–23 November 2003 period was analyzed in this paper, as well as the spatiotemporal characteristics of NO 5.3 μm radiation with an altitude around the location of 55°N 160°W. The altitude was divided into four regions (50–100 km, 100–150 km, 150–200 km, and 200–250 km), and it was found that the greatest amplification occurs at the altitude of 200–250 km. However, the radiance reached a maximum of 3.38 × 10−3 W/m2/sr at the altitude of 123 km during the aurora event, which was approximately 10 times higher than the usual value during “quiet periods”. Based on these findings, the spatiotemporal variations in NO 5.3 μm radiance within the range of latitude 51°S–83°N and longitude of 60°W–160°W were analyzed at 120 km, revealing an asymmetry between the northern and southern hemispheres during the recovery period. Additionally, the recovery was also influenced by the superposition of a second auroral event. The data used in this study were obtained from the OMNI database and the SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) infrared radiometer onboard the TIMED (Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics) satellite. Finally, the correlation of NO 5.3 μm radiance at 120 km with temperature, solar wind speed, auroral electrojet index (AE index), and Dst index were analyzed. It was found that only the Dst index had a good correlation with the radiance value. Furthermore, the correlation between the Dst index and radiance at different altitudes was also analyzed, and the highest correlation was found at 170 km.