2002-2003 Science Planning Summary

Oceans & Climate

Dr. Bernhard Lettau
Program Manager


NSF/OPP 00-03609
Station: RV Laurence M Gould
RPSC POC: Bob Kluckhohn
Research Site(s): Science of opportunity on cruises

Mesoscale, seasonal, and inter-annual variability of surface water carbon dioxide in the Drake Passage
Dr. Taro Takahashi
Columbia University
Lamont-Doherty Earth Observatory

Deploying Team Members: Colm Sweeney
Research Objectives: The Southern Ocean provides an important component of the global carbon budget. Cold surface temperatures with consequent low vertical stability, ice formation, and high winds produce a very active environment where the atmospheric and oceanic reservoirs readily exchange gaseous carbon. The Drake Passage is the narrowest point through which the Antarctic Circumpolar Current and its associated fronts must pass. This so-called chokepoint is an efficient site for measuring the latitudinal gradients of gas exchange.

Working from the R/V Laurence M. Gould, project team members will use equipment designed to measure both dissolved carbon dioxide (pCO2) and occasional total carbon dioxide in the surface waters during transects of the Drake Passage. This work extends similar measurements made aboard R/V Nathaniel B. Palmer, and complements other data collected on surface temperatures and currents. These several data sets, supplemented by satellite imagery, will enable scientists to make estimates of the net production and carbon export by the biological community, as well as the basic targets -- a quantitative description of the sources of pCO2 variability and a calculation of CO2 fluxes between the ocean and the atmosphere.

Field Season Overview:
One project team member will deploy to perform routine maintenance on the system. Contractor support staff on the USAP research vessels maintain and operate the pCO2 system and send data to the principal investigators each week. The data from this equipment compliments the data from other underway systems on the vessels (acoustic Doppler current profiler (ADCP), expendable bathythermograph (XBT), thermosalinograph (TSG), and weather systems) to give a more complete picture of environmental conditions across the Drake Passage.