Investigation of tropopause characteristics in the polar zone with the use of radio sounding data at Barrow station

Characteristics of the thermal tropopause are computed and analyzed on the base of 18-year series (1990–2007) of radio sounding data at Barrow station. The seasonal and interannual variability of tropopause height and temperature values, as well as of the relative humidity and wind speed at this level are investigated. Investigation of the tropopause “contrast” value, which defines the tropopause as the separating layer, is carried out. It is shown that during the period under review the tropopause has become stronger pronounced, mainly due to the temperature lapse rate increase in the lower stratosphere.