The Arctic is responding more rapidly to global warming than most other areas on our planet. Northward flowing Atlantic Water is the major means of heat advection towards the Arctic and strongly affects the sea ice distribution. Records of its natural variability are critical for the understanding of feedback mechanisms and the future of the Arctic climate system, but continuous historical records reach back only ~150 years. Here, we present a multidecadal scale record of ocean temperature variations during the last 2000 years, derived from marine sediments off Western Svalbard (79°N). We find that early-21st-century temperatures of Atlantic Water entering the Arctic Ocean are unprecedented over the past 2000 years and are presumably linked to the Arctic Amplification of global warming.

Data included in the frame of a joint ICSTI/PANGAEA IPY effort, see http://doi.pangaea.de/10.1594/PANGAEA.150150

Supplement to: Spielhagen, Robert F; Werner, Kirstin; Sørensen, Steffen Aagaard; Zamelczyk, Katarzyna; Kandiano, Evgenia S; Budéus, Gereon; Husum, Katrine; Marchitto, Thomas M; Hald, Morten (2011): Enhanced modern heat transfer to the Arctic by warm Atlantic water. Science, 331(6016), 450-453