The recent Atlantic cold anomaly: Causes, consequences, and related phenomena

• Published in: Annual Review of Marine Science
• Main Authors: Josey, Simon A., Hirschi, Joel J.M., Sinha, Bablu, Duchez, Aurélie, Grist, Jeremy P., Marsh, Robert
• Format: Review
• Language: English
• Published: 2018
• Subjects: Pacific; North Atlantic; North Atlantic oscillation
• Online Access: https://eprints.soton.ac.uk/417539/

Cold ocean temperature anomalies have been observed in the mid- to high-latitude North Atlantic on interannual to centennial timescales. Most notably, a large region of persistently low surface temperatures accompanied by a sharp reduction in ocean heat content was evident in the subpolar gyre from the winter of 2013-2014 to 2016, and the presence of this feature at a time of pervasive warming elsewhere has stimulated considerable debate. Here, we review the role of air-sea interaction and ocean processes in generating this cold anomaly and place it in a longer-term context. We also discuss the potential impacts of surface temperature anomalies for the atmosphere, including the North Atlantic Oscillation and European heat waves; contrast the behavior of the Atlantic with the extreme warm surface event that occurred in the North Pacific over a similar timescale; and consider the possibility that these events represent a response to a change in atmospheric planetary wave forcing.