Wind Driven Changes in Southern Ocean Residual Circulation, Ocean Carbon Reservoirs and Atmospheric CO2 Seminar
For more information regarding this seminar, please email Aurelie Duchez at aurelie.duchez@noc.ac.uk .
Event details
Physical Oceanography and Climate Seminars.
The Southern Ocean residual overturning circulation is thought to play an important role in the global carbon cycle for both past and future changes in climate, but the short duration of direct observations and ambiguity of the paleoceanographic record makes interpretation of the mechanism(s) involved difficult.
The effect of idealized wind-driven circulation changes in the Southern Ocean on atmospheric CO2 and the ocean carbon inventory is investigated using a suite of coarse-resolution, global ocean circulation and biogeochemistry experiments leading to changes in atmospheric pCO2 of ~20uatm. To further investigate these changes in pCO2, the components of a carbon partitioning framework are diagnosed. The ocean carbon inventory in our model varies through contrasting changes in the saturated, disequilibrium and biogenic (soft-tissue and carbonate) reservoirs, each varying by O(10--100) PgC.
Our experiments suggest that wind-induced changes in the model carbon inventory are dominated by the response of the global pycnocline, although there is an additional abyssal response when the peak westerly winds change their latitude. Given the caveats of parameterized eddy activity and only modest changes in surface buoyancy forcing, these results represent a large proportion of the change in glacial-interglacial CO2 that can be currently generated by altered circulation in a variety of models.
Speaker information
Dr Jon Lauderdale, University of Liverpool. I am a physical oceanographer and ocean biogeochemical modeller intrigued by the mechanisms through which the ocean can alter Earth's climate and atmospheric CO2 concentration both in the past and under future anthropogenic changes. I mostly use global coarse resolution numerical models of ocean circulation coupled to simplified biogeochemistry routines, but I also exploit composite tracers to reveal how different components of carbon and nutrient cycles operate.