Project: The seasonal dynamics of CO2, primary production, and DMS in the Western Antarctic Peninsula: Measurements of pools and processes using mass spectrometry

Description from NSF award abstract:
The Southern Ocean plays a key role in marine biogeochemistry and global climate. Along the Western Antarctic Peninsula (WAP), winter air temperatures have increased by more than 5 ºC over the past five decades, and sea ice duration and extent have decreased substantially, leading to dramatic ecological perturbations. The sensitivity of primary production and climate-active gas cycling to on-going changes in the physical and chemical environment of the WAP is the key to understanding potential biogeochemical climate feedbacks in this region. The objective of this project is to characterize and understand the seasonal dynamics of primary production and climate-active gases carbon dioxide (CO2) and dimethylsulfide (DMS) in the WAP. The project will examine (1) the relationships among seasonal changes in pCO2, temperature and light with respect to gross primary production, net primary production, and net community production; (2) the extent to which changes in surface water pCO2 and temperature drive ecological shifts in the dominant phytoplankton species assemblage composition, and alter key processes in the DMS cycle. The research will employ membrane inlet mass spectrometry to monitor dissolved gases in ambient seawater at the Palmer Station LTER site and conduct physiological/biochemical assays with tracer compounds. The research will provide unprecedented information on the temporal evolution of primary production and dissolved gas concentrations in the WAP in relation to surface hydrography and sea ice cover. Field studies will be supported by laboratory experiments with model species subjected to detailed studies of carbon metabolism. This project will contribute significantly to the understanding of seasonal biogeochemical dynamics in a region that is particularly sensitive to ongoing climate perturbations and important for the global air-sea exchange of CO2.

Related publications:
Young, J.N., Goldman, J., Kranz, S., Tortell, P.D., Morel, F.M.M. (2015) Slow carboxylation of Rubisco constrains the rate of carbon fixation during Antarctic phytoplankton blooms. New Phytologist 205 (1): 172-181. DOI: 10.1111/nph.13021

Goldman, J., Kranz, S., Young, J.N., Tortell, P.D., Bender, M., Morel, F.M.M. (2015) Gross and net production during the spring bloom along the Western Antarctic Peninsula New Phytologist 205 (1): 182-191. DOI: 10.1111/nph.13125

Kranz, S., Young, J.N., Goldman, J., Tortell, P.D., Bender, M., Morel, F.M.M. (2015) Low temperature reduces the energetic requirement for the CO₂ concentrating mechanism in diatoms. New Phytologist 205 (1): 192-201. DOI: 10.1111/nph.12976

Tortell, P.D., Asher, E.C., Dacey, J.W.H. Kranz, S., Young, J.N., Goldman, J. Ducklow, H., Grzymski, J. Stanley, R., Morel, F.M.M. (2014) Metabolic balance of coastal Antarctic waters revealed by autonomous high frequency pCO₂ and dO₂ /Ar measurements Geophysical Research Letters DOI: 10.1002/2014GL061266