WATER-VAPOR TEMPERATURE FEEDBACK IN THE FORMATION OF CONTINENTAL ARCTIC AIR - ITS IMPLICATION FOR CLIMATE

The ecology of the Arctic is sensitive to climate change. Recent analyses of temperature in the lower Arctic troposphere for the last 40 years has shown no trace of the expected arctic-wide greenhouse warming. Most climate models predict warming over sea ice regions during winter. In this paper, we discuss the interpretation of climate model results in terms of these new observational analyses. In particular, the observed spring time warming trend agrees with expected effects related to black carbonaceous aerosols. A possible process involving sulfate is tested for climate sensitivity. The rate of air mass transformation from maritime to continental polar air depends on the water vapor removal rate through condensation and precipitation. In turn, the removal of atmospheric water vapor reduces the greenhouse effect and enhances the cooling rate of the surface. Initially, this greenhouse cooling can dominate the warming trend from the increased levels of radiatively active trace gases. This work is an attempt to discuss a physical process leading to changes that potentially have significance for the ecology of the Arctic.