Simulation of the Impact of Instantaneous Solar UV Radiation Enhancements on the Middle Atmosphere via UV Radiation Reconstruction

This study reconstructed the ultraviolet (UV) radiation band ranging from 0.01 to 399.5 nm with a 5-minute time resolution during the solar minimum conditions on October 18, 2006. The aim was to examine the impact of solar flare events on the middle atmosphere. Instead of utilizing daytime scale data, a 5-minute resolution of 0.01–399.5 nm UV radiation was employed to observe how the middle atmosphere responds to sudden enhancements in solar UV radiation. The findings suggest minor temperature increases of 0.05 K in low latitudes, observed in both the lower thermosphere and the stratosphere. The UV radiation enhancement resulted in a 0.6% ozone increase in the stratosphere, causing subtle temperature elevations. Ozone increased by 4% at 80 km, with a -2% change at 60–70 km and a -6% change in the low thermosphere. Above 60 km, atmospheric density experienced a 0.05% increase, reaching up to 0.15% at 80–90 km. Thus, the response of the middle atmosphere's temperature and density to instantaneous UV radiation enhancements can be captured through UV radiation reconstruction. The simulation results were comparatively weaker than those of the previous study.