Climate response associated with the Southern Annular Mode in the surroundings of Antarctic Peninsula:: A multimodel ensemble analysis -: art. no. L16713

This paper is an attempt to extract an average picture of the response of the Southern Annular Mode (SAM) to increasing greenhouse gases (GHG) forcing from a multimodel ensemble of simulations conducted in the framework of the IPCC 4th assessment experiments. Our analysis confirms that the climate change signal in the mid-to high southern latitudes projects strongly into the positive phase ( PP) of the SAM. Over the present climate time slice ( 1970 - 1999), multimodel ensemble mean reproduce the regional warming around the Antarctic Peninsula (AP) associated with the SAM. When increasing GHG ( future time slice, 2070 - 2099), warming in the neighborhoods of the AP and decreasing sea-ice volume in the sea-ice edge region in the Amundsen and Weddell Seas intensifies, suggesting that recent observed sea-ice trends around AP could be associated to anthropogenic forcings. Changes in surface temperature and sea-ice are consistent with anomalous atmospheric heat transport associated with circulation anomalies.