Mar 18, 2016

Suppressed midlatitude summer atmospheric warming by Arctic sea ice loss during 1979–2012

Wu, Qigang, Cheng, Luyao, Chan, Duo, Yao, Yonghong, Hu, Haibo, Yao, Ying
Geophysical Research Letters
  • States that rapid Arctic warming, sea ice decline, and weakening summer circulation have coincided with an increasing number of extreme heat waves and other destructive weather events in the Northern Hemisphere (NH) midlatitudes in summer, since the 1980s
  • States there is uncertainty about whether such high-impact events are related to Arctic warming and/or ice loss
  • Uses model simulations to attribute effects of sea ice loss and other factors on observed summer climate trends during 1979–2012
  • Finds that ongoing greenhouse gas buildup and the resulting sea surface temperature warming outside the Arctic explains nearly all land warming and a significant portion of observed weakening zonal winds in the NH midlatitudes
  • The research also finds, however, that sea ice loss creates a negative feedback by inducing a negative Arctic Oscillation (AO) type circulation with significant summer surface and tropospheric cooling trends over large portions of the NH midlatitudes; this has the potential to reducing the warming and might reduce the probability of regional severe hot summers