Selected CFC and HCFC Tracers Observed During the Gulf of Mexico East Coast Carbon (GOMECC) Cruise

While the coastal ocean is small in area, it is the bridge between the terrestrial environment and the deep ocean. Research on the role of this region in the cycling of carbon and the air-sea flux of CO2 has been increasing. In order to understand the biogeochemical cycling involved in this region, it is necessary to examine the potential movement of water masses onto or off of the continental shelf. The recent observation of acidic water upwelling onto the shelf on the west coast of the US is evidence of the potentially significant interaction between shelf waters and deeper open ocean waters [Feely et al., 2008]. During the Gulf of Mexico and East Coast Carbon (GOMECC) cruise in 2007, we measured depth profiles and saturation anomalies of the tracers: CFC-11, CFC-12, CFC-113, HCFC-22, and HCFC-142b. This cruise was the first comprehensive survey of inorganic carbon, nutrients and other biogeochemical parameters along the Gulf of Mexico and East coasts of the US. We are using the tracer data to examine the circulation of water masses between the shelf region and the open ocean. We will present the results from the depth profile and saturation anomaly measurements of these tracers. Feely, R.A., C.L. Sabine, J.M. Hernandez-Ayon, D. Ianson, and B. Hales (2008) Science, 320(5882), doi: 10.1126/science.1155676, 1490-1492.