Webinar | The Arctic Climate System by Prof. Manfred Wendisch

Webinar on the Arctic climate system by Prof. Manfred Wendisch

In the last 20 to 30 years, a new Arctic has developed right before our eyes in response to global warming. Truly substantial and rapid changes of Arctic climate parameters have been observed; they continue to proceed at an unexpected speed and vehemence. One prominent example of these ongoing climate changes is the dramatic decline of sea ice in the Arctic Ocean, which seems mainly be determined by atmospheric near-surface warming. Overall, the Arctic sea-ice cover observed at the end of summer has halved in the past 40 years. Another apparent sign of the current climate changes in the Arctic is the accelerated increase of the Arctic near-surface air temperature. Both and further obvious climate changes result from the elevated sensitivity of the Arctic climate system to global warming, compared to that at lower latitudes, which amplifies the impact of a variety of evolving local and remote processes and feedback mechanisms. The enhanced efficiency of these interlinked mechanisms is promoted by Arctic-specific characteristics (e.g., low sun, polar day and night, high surface albedo), and particular atmospheric circumstances (e.g., pronounced near-surface temperature inversions, frequent and persistent low-level clouds, widespread moisture inversions). Especially, mixed-phase clouds play a decisive role in feedback processes in the Arctic. The mechanisms behind the enhanced response of the Arctic climate system to global warming are generally referred to as Arctic amplification. The presentation will give a general overview of possible reasons for Arctic Amplification and discuss new findings in this area.