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Carbonate Dissolution Enhanced by Ocean Stagnation and Respiration at the Onset of the Paleocene‐Eocene Thermal Maximum
Author(s) -
Ilyina Tatiana,
Heinze Mathias
Publication year - 2019
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 - 10.1029/2018gl080761
Subject(s) - carbonate , geology , carbon cycle , dissolution , oceanography , thermohaline circulation , climate change , ocean current , climatology , earth science , ecosystem , chemistry , ecology , organic chemistry , biology
The Paleocene‐Eocene Thermal Maximum was a transient, carbon‐induced global warming event, considered the closest analog to ongoing climate change. Impacts of a decrease in deepwater formation during the onset of the Paleocene‐Eocene Thermal Maximum suggested by proxy data on the carbon cycle are not yet fully understood. Using an Earth System Model, we find that changes in overturning circulation are key to reproduce the deoxygenation and carbonate dissolution record. Weakening of the Southern Ocean deepwater formation and enhancement of ocean stratification driven by warming cause an asymmetry in carbonate dissolution between the Atlantic and Pacific basins suggested by proxy data. Reduced ventilation results in accumulation of remineralization products (CO 2 and nutrients) in intermediate waters, thereby lowering O 2 and increasing CO 2 . As a result, carbonate dissolution is triggered throughout the water column, while the ocean surface remains supersaturated. Our findings contribute to understanding of the long‐term response of the carbon cycle to climate change.