Possible descent across the ‘Tropopause’ in Antarctic winter
Descent of air from stratosphere to troposphere in Antarctic winter is proposed to be feasible, because of forcing from above by subsidence plus wave-breaking, together with suction from below to resupply the katabatic winds which flow down the slopes of the Antarctic Plateau in the boundary layer. In Antarctic winter, there is no real tropopause to prevent such descent, hence the quotes in the title: the temperature profile is often that of a radiative equilibrium atmosphere. Such descent would be important because the dryness and low precipitation over the Antarctic Plateau would be less altered during global warming, because there would be an alternative fractionation pathway for H2O18 and HDO in Antarctic ice-cores, and because the ozone budget in the unpolluted troposphere of the southern hemisphere would be significantly different. Each of these features could have a major impact on climate or on the study of climate.