Mean vertical profiles of temperature and absolute humidity from a 12-year radiosounding data set at Terra Nova Bay (Antarctica)

A set of 1330 radiosoundings was performed at the Italian station of Terra Nova Bay in Antarctica during 12 measurement campaigns from 1987 to 1998. These measurements were separately analyzed for the various 10-day periods from mid-October to mid-February, to determine the mean vertical profiles of air pressure and temperature in the troposphere and lower stratosphere, and those of moisture parameters in the troposphere. The temperature data were corrected for the errors due to radiation and heat exchange processes and for the lag errors of the sensor. Due to temperature dependence and other dry bias effects, the humidity errors were also taken into account. The tropospheric temperature was found to present average values of its vertical gradient varying between −5.4 and −6.3 K/km, while its minimum height associated with the tropopause gradually lowered from 13.7 to 7.9 km. Total water vapor content increased correspondingly from 0.12 to 0.36 g cm−2 during the first two months and decreased to 0.26 g cm−2 in the following period. Stratospheric temperature was observed to increase during the first 2 months by about 15 K in the region below the 24-km height and to appreciably decrease at upper levels, maintaining almost stable features during the subsequent months.