Subtropical Arctic Ocean temperatures during the Palaeocene/Eocene thermal maximum
Date of Original Version
The Palaeocene/Eocene thermal maximum, ∼55 million years ago, was a brief period of widespread, extreme climatic warming, that was associated with massive atmospheric greenhouse gas input. Although aspects of the resulting environmental changes are well documented at low latitudes, no data were available to quantify simultaneous changes in the Arctic region. Here we identify the Palaeocene/Eocene thermal maximum in a marine sedimentary sequence obtained during the Arctic Coring Expedition. We show that sea surface temperatures near the North Pole increased from ∼18°C to over 23°C during this event. Such warm values imply the absence of ice and thus exclude the influence of ice-albedo feedbacks on this Arctic warming. At the same time, sea level rose while anoxic and euxinic conditions developed in the ocean's bottom waters and photic zone, respectively. Increasing temperature and sea level match expectations based on palaeoclimate model simulations, but the absolute polar temperatures that we derive before, during and after the event are more than 10°C warmer than those model-predicted. This suggests that higher-than-modern greenhouse gas concentrations must have operated in conjunction with other feedback mechanisms-perhaps polar stratospheric clouds or hurricane-induced ocean mixing-to amplify early Palaeogene polar temperatures. © 2006 Nature Publishing Group.
Publication Title, e.g., Journal
Sluijs, Appy, Stefan Schouten, Mark Pagani, Martijn Woltering, Henk Brinkhuis, Jaap S. Damsté, Gerald R. Dickens, Matthew Huber, Gert J. Reichart, Ruediger Stein, Jens Matthiessen, Lucas J. Lourens, Nikolai Pedentchouk, Jan Backman, Kathryn Moran, Steve Clemens, Thomas Cronin, Frédérique Eynaud, Jérôme Gattacceca, Martin Jakobsson, Ric Jordan, Michael Kaminski, John King, Nalân Koc, Nahysa C. Martinez, David McInroy, Theodore C. Moore, Matthew O'Regan, Jonaotaro Onodera, Heiko Pälike, Brice Rea, Domenico Rio, Tatsuhiko Sakamoto, David C. Smith, Kristen E. St John, and Itsuki Suto. "Subtropical Arctic Ocean temperatures during the Palaeocene/Eocene thermal maximum." Nature 441, 7093 (2006). doi: 10.1038/nature04668.