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Repeated Near‐Collapse of the Pliocene Sea Surface Temperature Gradient in the North Atlantic
Author(s) -
Naafs B. D. A.,
Voelker A. H. L.,
Karas C.,
Andersen N.,
Sierro F. J.
Publication year - 2020
Publication title -
paleoceanography and paleoclimatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.927
H-Index - 127
eISSN - 2572-4525
pISSN - 2572-4517
DOI - 10.1029/2020pa003905
Subject(s) - sea surface temperature , geology , benthic zone , middle latitudes , oceanography , pleistocene , climatology , gulf stream , deglaciation , period (music) , holocene climatic optimum , north atlantic oscillation , paleontology , climate change , holocene , physics , acoustics
Sea surface temperature (SST) is used to infer past changes in the state of the climate system. Here we use a combination of newly generated and published organic paleothermometer records, together with novel high‐resolution benthic foraminiferal δ 18 O stratigraphy, from four sites in the midlatitude North Atlantic (41–58°N) to reconstruct the long‐term evolution of the latitudinal SST gradient during the Pliocene and early Pleistocene (4.0 to 2.4 Myr), the last time atmospheric CO 2 reached concentrations above 400 ppmv. We demonstrate that the latitudinal SST gradient in the North Atlantic nearly collapsed twice during this period. We conclude that the latitudinal SST gradient in the midlatitude North Atlantic has two end‐members: a maximum as existing at present and a minimum that existed during certain periods of the (late) Pliocene. Our results suggest that the 400‐ppmv Pliocene world was more dynamic than currently thought.