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Enhanced circulation during a warm period
Author(s) -
Ravelo Ana Christina,
Andreasen Dyke H.
Publication year - 2000
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/1999gl007000
Subject(s) - ocean gyre , thermohaline circulation , north atlantic deep water , shutdown of thermohaline circulation , oceanography , geology , ocean current , boundary current , climatology , context (archaeology) , atlantic multidecadal oscillation , tropical atlantic , benthic zone , atlantic equatorial mode , subtropics , sea surface temperature , paleontology , fishery , biology
The Early Pliocene is the most recent interval in which equilibrium oceanic conditions can be studied in the context of global warmth relative to today. To characterize thermohaline circulation during this warm period (4.4–3.1 Ma) we combined new benthic foraminiferal isotopic data from the southeast Atlantic with published data, and reconstructed Pacific and Atlantic Ocean nutrient distributions. The data indicate enhanced ventilation of the deep Atlantic and intermediate Pacific during the Early Pliocene. Enhanced ventilation implies that delivery of surface water to high latitudes in western boundary currents of North Pacific and Atlantic subtropical gyres was probably also enhanced. Future modeling of this warm period needs to reconcile reduced meridional surface temperature gradients with enhanced subtropical gyre and thermohaline circulation.