Seasonal variations of the atmospheric temperature structure at South Pole

Abstract

Fe/Rayleigh lidar measurements are combined with the high‐altitude balloonsonde data and used to characterize the seasonal variations of atmospheric temperature at South Pole from the surface (2.835 km) to 110 km altitude. Twelve‐month oscillations, associated with solar UV absorption by ozone, dominate the seasonal variations of temperature throughout the stratosphere and lower mesosphere from 10 to 60 km. In the mesopause region between 70 and 100 km, 12‐ and 6‐month oscillations dominate the seasonal variations with the warmest temperatures occurring near the spring and fall equinoxes. During the month of March, temperature near 80 km is more than 25 K warmer than MSIS‐00. The spring and fall temperature maxima in the mesopause region appear to be associated with the combined effects of the annual variations in adiabatic heating and cooling and the annual variations in solar heating, which are 180° out of phase. During the month of June, the stratopause and mesopause temperatures are about 20–30 K colder than the model predictions. The seasonal temperature variations are the largest near 85 km altitude, where they are approximately 85 K peak to peak.