EOL/CGD Seminar: Atmospheric perspectives on Southern Ocean Carbon cycling

Britton Stephens

Earth Observing Laboratory,
National Center for Atmospheric Research

It has been suggested that increases in circumpolar winds over the Southern Ocean are leading to greater upwelling of deep water and reduced efficiency of anthropogenic CO2 uptake around Antarctica.  Both points are controversial, but it is clear that the Southern Ocean will play an important role in future trends in atmospheric CO2 and climate.  Models used to project Southern Ocean carbon cycling, including CESM, are sensitive to a delicate balance of physical, biological, and anthropogenic forcing in this region.  I will present various atmospheric observations that can provide insight into Southern Ocean carbon fluxes and tests for model representations of their controlling processes.  These include long-term records of spatial gradients in atmospheric CO2 concentration across the Southern Ocean, observations of seasonal cycles in atmospheric O2 and CO2 at high southern latitude stations, and measurements of O2 and CO2 from the global airborne HIPPO campaigns.  Observations of atmospheric O2 are valuable in resolving ocean carbon processes because air-sea O2 fluxes respond in the same direction as CO2 for solubility forcing, in the opposite direction for biological forcing, and do not respond to anthropogenic forcing.  I will also describe a recently funded project to make continuous shipboard observations of atmospheric O2 and CO2 in the Drake Passage.

Friday, 25 February 2011, 3:30 PM

Refreshments 3:15 PM

NCAR-Foothills Laboratory

3450 Mitchell Lane

Bldg 2 Auditorium (Rm1022)

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Tuesday, February 22, 2011
Friday, February 25, 2011