Summary
Arctic and Antarctic tropopause is formed under extreme climate conditions, both in troposphere and stratosphere. In the troposphere, distribution of orography, ice sheet and stationary atmospheric centres of action is distinct. This results in individual patterns of the tropopause anomalies due to troposphere temperature and pressure influence. In the stratosphere, the polar regions differ not only by the air temperatures, but also by the spatial distribution of intense ozone losses which influence the air cooling in the lowermost stratosphere, the cold point/tropopause elevation as well as the tropopause sharpness decrease. We analyze climatology of the tropopause in polar and high-latitude regions by NCEPNCAR reanalysis data of the 1979-2008 period. The role of the troposphere and stratosphere in the observed polar tropopause anomaly distribution and tendencies is compared using corresponding temperature fields and their long-term changes. Important result is asymmetrically elevated Antarctic tropopause (12-14 km) in winter-spring period, when Arctic anomalies show typically very low tropopause, about 8-9 km. By location, the tropopause anomalies correspond to cold anomalies in stratosphere and troposphere, respectively. This distinction suggests the dominant contribution of the stratosphere (troposphere) on the Antarctic (Arctic) tropopause anomaly occurrence in austral (boreal) winter and spring. The decadal tendencies in behaviour of the tropopause anomalies are compared and the effects of the regional climate changes are discussed.