Atlantic Ocean Carbon Experiment (acex): Implementation of Eddy Covariance Implementation of Eddy Covariance CO2 Flux Measurements on the SW Atlantic Ocean and Results from the Second Cruise
Abstract
The project observational and numerical study of heat, momentum and CO2 fluxes at the ocean-atmosphere interface in the South Atlantic Ocean - Atlantic Ocean Carbon Experiment (ACEx) combines observational and modeling approaches to characterize heat, momentum and CO2 fluxes at the ocean-atmosphere interface in the South Atlantic Ocean. This project is part of an innovative initiative aimed at providing a better understanding of the chemical, physical and dynamic processes of ocean-atmosphere interaction in micro and meso-scales at the South Atlantic Ocean, as well as fluxes across this interface. The ACEx project has performed three cruises so far, collecting measurements with CTDs and XBTs, launching radiosondes, and deploying a micro-meteorological tower to make in situ measurements of heat, momentum and CO2 fluxes. Our successful deployment of this tower represents the first use of a CO2 flux measurement system using eddy covariance technique in the Southwestern Atlantic Ocean. In this work, we present results from the second ACEx cruise, in which the crew onboard the Hydro-oceanographic Vessel Cruzeiro do Sul took measurements at 31 stations between Paranaguá (PR) and Chuí (RS). In addition to physical data, this cruise collected phytoplankton and nutrient data, allowing carbonic gas fluxes to be analyzed and compared with both physical and biological forcings. The highest chlorophyll concentrations were found in water derived from the La Plata River, which showed low salinity waters close to the surface. The influence of these waters was observed mainly at the southernmost stations of the cruise, coincident with increases on the CO2 fluxes that had remained slightly negative until then. This suggests that the biological forcings might have a significant impact on the gas fluxes in this area, through both respiration and the consumption of organic matter. We are currently working to apply circulation and biogeochemical models to evaluate the importance of each forcing in the absorption and release of carbonic gas in the area.
- Publication:
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AGU Spring Meeting Abstracts
- Pub Date:
- May 2013
- Bibcode:
- 2013AGUSMOS24A..07S
- Keywords:
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- 0312 ATMOSPHERIC COMPOSITION AND STRUCTURE / Air/sea constituent fluxes;
- 4594 OCEANOGRAPHY: PHYSICAL / Instruments and techniques;
- 3307 ATMOSPHERIC PROCESSES / Boundary layer processes;
- 4504 OCEANOGRAPHY: PHYSICAL / Air/sea interactions