Open AccessNumerical evidence for thermohaline circulation reversals during the Maastrichtian
Author(s) -
Pucéat Emmanuelle,
Donnadieu Yannick,
Ramstein Gilles,
Fluteau Frédéric,
Guillocheau François
Publication year - 2005
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1029/2005gc000998
Subject(s) - thermohaline circulation , geology , oceanography , arctic , climatology , inflow , ocean current , shutdown of thermohaline circulation , the arctic , north atlantic deep water
The sensitivity of the Maastrichtian thermohaline circulation to the opening/closing of marine communications between the Arctic and North Pacific oceans is investigated through a set of numerical experiments using the model CLIMBER‐2 (Earth Model of Intermediate Complexity). We show here that the opening or closing of an Arctic‐Pacific marine gateway induces transitions between different equilibrium states of the thermohaline circulation. Sensitivity tests of the inferred modes of thermohaline circulation to atmospheric CO 2 level changes have also been explored. An abrupt switch in deep convection from high northern to high southern latitudes, a change consistent with isotopic evidences, is reproduced by our simulations. The switch is caused by a combination of increased atmospheric CO 2 concentration and inflow in the North Pacific of low‐salinity Arctic waters when the Arctic‐Pacific marine gateway is opened. The state of the gateway (open/closed) may have changed rapidly through variations in sea level that have been inferred for the Maastrichtian period.