The Impact of Orbital Precession on Air-Sea CO$_{2}$ Exchange in the Southern Ocean | CU Experts

Orbital precession has been linked to glacial cycles and the atmospheric; carbon dioxide (CO2) concentration, yet the direct impact of precession; on the carbon cycle is not well understood. We analyze output from an; Earth system model configured under different orbital parameters to; isolate the impact of precession on air-sea CO2 flux in the Southern; Ocean – a component of the global carbon cycle that is thought to play; a key role on past atmospheric CO2 variations. Here, we demonstrate that; periods of high precession are coincident with anomalous CO2 outgassing; from the Southern Ocean. Under high precession, we find a poleward shift; in the southern westerly winds, enhanced Southern Ocean meridional; overturning, and an increase in the surface ocean partial pressure of; CO2 along the core of the Antarctic Circumpolar Current. These results; suggest that orbital precession may have played an important role in; driving changes in atmospheric CO2

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