Recorded presentation7B.1
Recently Intensified Arctic Atmosphere-Ice-Ocean Interaction and Accelerated Sea Ice Reduction
Xiangdong Zhang, University of Alaska, Fairbanks, AK
Substantial changes have been manifested in the Arctic climate system in recent decades. In conjunction with the general global warming forcing, many of these regional changes have been demonstrated to be tightly associated with variability of and changes in atmospheric and oceanic circulations and their interactions. The polarity of the Arctic/North Atlantic Oscillation (AO/NAO) toward its positive phase causes a spread of warm surface air temperature into the Arctic Ocean and strengthens the North Atlantic warm water intrusion through Fram Strait, which has predominantly accounted for the observed Arctic sea ice decrease. However, the AO/NAO has shifted back to the neutral and even slight negative phase in the most recent years, while Arctic sea ice declining has continued and even accelerated markedly, leading to an Arctic climate paradox. In this study, we detected drastic changes in atmospheric and oceanic circulations, resulting in an intensification of Arctic atmosphere-ice-ocean interactions. This intensified interactions significantly amplified Arctic warming and accelerated sea ice reduction, including the extreme sea ice loss in 2007. The identification of the new atmospheric and oceanic circulation changes may shed light on recent argument about a tipping point of Arctic climate change.
Session 7B, High-latitude air-sea interaction
Tuesday, 13 January 2009, 3:30 PM-5:15 PM, Room 128B
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