Mid-Pliocene equatorial Pacific sea surface temperature reconstruction: a multi-proxy perspective
The Mid-Pliocene is the most recent interval of sustained global warmth, which can be used to examine conditions predicted for the near future. An accurate spatial representation of the low-latitude Mid-Pliocene Pacific surface ocean is necessary to understand past climate change in the light of forecasts of future change. Mid-Pliocene sea surface temperature (SST) anomalies show a strong contrast between the western equatorial Pacific (WEP) and eastern equatorial Pacific (EEP) regardless of proxy (faunal, alkenone and Mg/Ca). All WEP sites show small differences from modern mean annual temperature, but all EEP sites show significant positive deviation from present-day temperatures by as much as 4.4°C. Our reconstruction reflects SSTs similar to modern in the WEP, warmer than modern in the EEP and eastward extension of the WEP warm pool. The east-west equatorial Pacific SST gradient is decreased, but the pole to equator gradient does not change appreciably. We find it improbable that increased greenhouse gases (GHG) alone would cause such a heterogeneous warming and more likely that the cause of Mid-Pliocene warmth is a combination of several forcings including both increased meridional heat transport and increased GHG.
Citation Information
Publication Year | 2009 |
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Title | Mid-Pliocene equatorial Pacific sea surface temperature reconstruction: a multi-proxy perspective |
DOI | 10.1098/rsta.2008.0206 |
Authors | Harry J. Dowsett, Marci M. Robinson |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences |
Index ID | 70003482 |
Record Source | USGS Publications Warehouse |
USGS Organization | Eastern Geology and Paleoclimate Science Center |