CR 70:19-27 (2016)  -  DOI: https://doi.org/10.3354/cr01412

ABSTRACT: Focusing on the extremely cold winter of 2013-2014 over North America, we used both reanalysis datasets and an atmospheric general circulation model (AGCM) to examine the relationship between changes in the Arctic Ocean during the summer and atmospheric circulations over North America during the subsequent winter. In the reanalysis datasets, air temperatures over North America were extremely cold during the winter of 2013-2014, while summer sea surface temperatures (SST) over the Barents Sea in 2013 were anomalously warm. This relationship is not limited to 2013–2014; we found that the interannual variability of SST over the Barents Sea is significantly correlated with the atmospheric circulations and air temperatures over North America during the winter. Also, positive SST anomalies over the Barents Sea during summer persist through autumn and winter. These results indicate that variations in Barents Sea SST have a memory longer than a season, and hence are important for the interseasonal link from summer to winter, which is likely related to the atmosphere and temperature anomalies in the following winter. AGCM experiments driven by the observed SST and sea ice concentration successfully reproduced the warmer temperature over the Barents Sea from summer to winter. The winter large-scale atmospheric anomalies in the experiments were similar to observed atmospheric anomalies in the winter of 2013-2014. Finally, both our observational analysis and the model experiments suggest that the summer to autumn Barents Sea SST, rather than Arctic sea ice anomalies, may hold a key to predicting the winter atmospheric circulation and the winter air temperature over North America.

KEY WORDS: Arctic Ocean · Summer SST · North America · Winter air temperature · Cold winter · Extreme climate event · Interannual variation