Title
Pronounced zonal heterogeneity in Eocene southern high-latitude sea surface temperatures
Author
Douglas, P.M.J.
Affek, H.P.
Ivany, L.C.
Houben, A.J.P.
Sijp, W.P.
Sluijs, A.
Schouten, S.
Pagani, M.
Publication year
2014
Abstract
Paleoclimate studies suggest that increased global warmth during the Eocene epoch was greatly amplified at high latitudes, a state that climate models cannot fully reproduce. However, proxy estimates of Eocene near-Antarctic sea surface temperatures (SSTs) have produced widely divergent results at similar latitudes, with SSTs above 20 °C in the southwest Pacific contrasting with SSTs between 5 and 15 °C in the South Atlantic. Validation of this zonal temperature difference has been impeded by uncertainties inherent to the individual paleotemperature proxies applied at these sites. Here, we present multiproxy data from Seymour Island, near the Antarctic Peninsula, that provides well-constrained evidence for annual SSTs of 10-17 °C (1σ SD) during the middle and late Eocene. Comparison of the same paleotemperature proxy at Seymour Island and at the East Tasman Plateau indicate the presence of a large and consistent middle-to-late Eocene SST gradient of ~7 °C between these two sites located at similar paleolatitudes. Intermediate- complexity climate model simulations suggest that enhanced oceanic heat transport in the South Pacific, driven by deep-water formation in the Ross Sea, was largely responsible for the observed SST gradient. These results indicate that very warm SSTs, in excess of 18 °C, did not extend uniformly across the Eocene southern high latitudes, and suggest that thermohaline circulation may partially control the distribution of high-latitude ocean temperatures in greenhouse climates. The pronounced zonal SST heterogeneity evident in the Eocene cautions against inferring past meridional temperature gradients using spatially limited data within given latitudinal bands.
Subject
Earth / Environmental
PG - Petroleum Geosciences
ELSS - Earth, Life and Social Sciences
Geological Survey Netherlands
Geosciences
Energy / Geological Survey Netherlands
Climate modeling
Clumped isotopes
High-latitude climate
Organic geochemistry
Paleooceanography
Calcium carbonate
Strontium
Antarctica
Benthic foraminifera
Eocene
Geochemistry
Latitude
Nonhuman
Paleoclimate
sea surface temperature
Sediment
Simulation
Thermohaline circulation
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http://resolver.tudelft.nl/uuid:163ff425-cac9-4304-b3c7-d5b8c0be3e1e
DOI
https://doi.org/10.1073/pnas.1321441111
TNO identifier
503267
Publisher
National Academy of Sciences
ISSN
1091-6490
Source
Proceedings of the National Academy of Sciences of the United States of America, 111 (18), 6582-6587
Document type
article