National Oceanic and Atmospheric Administration
Global Monitoring Division (GMD)
Supporting Stations: ARSV Laurence M. Gould
Research Locations: Drake Passage
The Antarctic Circumpolar Current is the strongest wind-driven ocean current on the planet. Encircling the entire continent, it has a natural “chokepoint” at the Drake Passage between South America and the Antarctic Peninsula. Since 1994, this project has collected data during all Drake Passage crossings, first on the R/V Polar Duke, then the ARSV Laurence M. Gould. The installed equipment measures underway surface partial pressure of carbon dioxide (pCO2) and takes discrete samples of other parameters of interest to studying the carbon system, e.g., total carbon dioxide (TCO2) and isotopic (13C/12C and 14C/12C) ratios in surface TCO2. During selected southbound Drake Passage transects of O-260-L (Sprintall), this group also obtains direct measurements from seawater samples and collects physical hydrographic data using eXpendable BathyThermograph (XBT) and eXpendable Conductivity, Temperature, Depth (XCTD) probes. Since 2012, this group has also conducted underway measurements of atmospheric oxygen and nitrogen. The measurement set provides an opportunity to increase understanding of the major processes that control spatial, seasonal, and inter-annual variability of dissolved carbon dioxide in the waters of the Drake Passage as well as biogeochemical fluxes in the Southern Ocean.
Field Season Overview:
Project participants deploy to one or two port calls per year to maintain and upgrade equipment. Onboard support staffers and technicians monitor the equipment, turn it on and off to avoid data collection in other nations’ Exclusive Economic Zones (EEZ), and perform maintenance as needed. During Janet Sprintall’s O-260 Drake Passage transects, contract technicians collect water samples for this project. At the end of each cruise the data is distributed to the project PIs and collaborators as well as the onboard science parties.
Deploying Team Members:
Britton Stephens (Co-PI)