An interesting new paper on Arctic sea ice has just been published. According to the conclusions of “Influence of high-latitude atmospheric circulation changes on summertime Arctic sea ice“:
Although positive feedbacks between sea ice and the Arctic circulation exist, we find that these are small during summer. Instead, circulation variations over the Arctic have been a significant factor in driving sea-ice variability since 1979, and have had a non-trivial contribution to the total surface temperature trend over Greenland and northeastern Canada39 . The potentially large contribution of internal variability to sea-ice loss over the next 40 years reinforces the importance of natural contributions to sea-ice trends over the past several decades. The similarity of high-latitude circulation variability associated with sea-ice loss to the teleconnections with the tropical Pacific suggests a contribution of sea-ice losses from SST trends across the tropical Pacific Ocean. Decadal trends in the hemispheric circulation are an important driver of Arctic climate change, and therefore a significant source of uncertainty in projections of sea ice. Better understanding of these teleconnections and their representation in global models under increasing greenhouse gases may help increase predictability on seasonal to decadal timescales.