Mar 18, 2016

Future Arctic sea ice loss reduces severity of cold air outbreaks in midlatitudes

Ayarzagüena, Blanca, Screen, James A.
Geophysical Research Letters
  • States previous studies on the effects of Arctic sea ice loss on cold air outbreaks (CAOs) in midlatitudes have defined CAOs relative to the present-day climate, but changes in CAOs, defined in such a way, may reflect changes in mean climate and not in weather variability, and society is more sensitive to the latter
  • This study revisits the above topic but applies changing temperature thresholds relating to climate conditions of the time
  • States CAOs do not change in frequency or duration in response to projected sea ice loss
  • States CAOs do, however, become less severe, mainly due to advection of warmed polar air, since the dynamics associated with the occurrence of CAOs are largely not affected
  • Finds CAOs weaken even in midlatitude regions where the winter mean temperature decreases in response to Arctic sea ice loss
  • States the results are robustly simulated by two atmospheric models prescribed with differing future sea ice states and in transient runs where external forcings are included