caa a22 4500 605471789 CHVBK 20210128100334.0 cr unu---uuuuu 210128e20150901xx s 000 0 eng 10.1007/s00382-014-2368-1 doi (NATIONALLICENCE)springer-10.1007/s00382-014-2368-1 Role of sea surface temperature, Arctic sea ice and Siberian snow in forcing the atmospheric circulation in winter of 2012-2013 [Elektronische Daten] [Yannick Peings, Gudrun Magnusdottir] During the 2012-2013 winter, the negative phase of the North Atlantic Oscillation (NAO) predominated, resulting in a cold winter over Europe and northern Asia punctuated by episodes of frigid weather. This climate anomaly is part of a recent trend towards negative values of the NAO index that has occurred over recent winters. The negative trend of the NAO may be related to atmospheric internal variability butit may also be partly forced by slowly varying components of the climate system. In the present study, we investigate the influence of surface conditions on the atmospheric circulation for the 2012-2013 winter using an atmospheric global climate model. In particular, the role of low Arctic sea ice concentration, warm tropical/North Atlantic sea surface temperature and positive Siberian snow cover anomalies are isolated by prescribing them in a set of different numerical experiments. Our simulations suggest that each of these surface forcings favored a negative NAO during the 2012-2013 winter. In our model, the combined NAO response to tropical/North Atlantic SST, Arctic sea ice and Siberian snow anomalies accounts for about 30% of the observed NAO anomaly. Different physical mechanisms are explored to elucidate the atmospheric responses and are shown to involve both tropical and extratropical processes. Springer-Verlag Berlin Heidelberg, 2014 Climate variability nationallicence North Atlantic Oscillation nationallicence Ocean-atmosphere interactions nationallicence Arctic sea ice nationallicence Siberian snow nationallicence 2012-2013 winter nationallicence Peings Yannick Department of Earth System Science, University of California, Irvine, 92697-3100, Irvine, CA, USA aut Magnusdottir Gudrun Department of Earth System Science, University of California, Irvine, 92697-3100, Irvine, CA, USA aut Climate Dynamics Springer Berlin Heidelberg 45/5-6(2015-09-01), 1181-1206 0930-7575 45:5-6<1181 2015 45 382 https://doi.org/10.1007/s00382-014-2368-1 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00382-014-2368-1 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Peings Yannick Department of Earth System Science, University of California, Irvine, 92697-3100, Irvine, CA, USA aut NATIONALLICENCE 700 1- Magnusdottir Gudrun Department of Earth System Science, University of California, Irvine, 92697-3100, Irvine, CA, USA aut NATIONALLICENCE 773 0- Climate Dynamics Springer Berlin Heidelberg 45/5-6(2015-09-01), 1181-1206 0930-7575 45:5-6<1181 2015 45 382