Fe/Rayleigh lidar measurements and balloon observations
made recently at the geographic South Pole are used to
characterize the monthly mean winter temperature profiles
from the surface to about 110 km. The measured
temperatures during mid-winter in both the stratopause and
mesopause regions are 20–30 K colder than current model
predictions. These differences are caused by weaker than
expected compressional heating associated with subsidence
over the polar cap. The measured mesopause temperature
responds much more rapidly to changes in sunlight than
model predictions, which suggests that IR heating by CO2
absorption may also be important to the thermal balance in
the mesopause region.Ope