St. Petersburg Coastal and Marine Science Center
Enhancement of Satellite Maps of Carbon Fluxes and Saturation State
Currently global warming and ocean acidification models attempt to predict changes in the geochemistry of pelagic (deep open ocean) waters in response to increasing concentrations of atmospheric CO2. These models do not apply to coastal systems due to the extreme variability. The dynamic nature of coastal marine systems is driven by high rates of biological and geochemical processes over brief spatial and temporal scales, relative to pelagic waters. High variability in coastal waters is due to respiration processes of benthic communities, high inputs of fresh water from streams and groundwater sources, high inputs of organic carbon and nutrients from surface and groundwater, temperature and salinity fluctuations, and increased pCO2 concentrations in air forced seaward from land. Field data, collected in the nearshore, can be used to improve current ocean acidification models. The USGS is partnering with NOAA to enhance regional models and the application of satellite imagery to the monitoring and understanding of ocean acidification on the Florida Shelf.
Satellite data provide a synoptic view of carbon fluxes and carbonate saturation states on the Florida Shelf, although are limited to how far inshore they are useful. Field data can provide the spatial resolution of the variability lacking from satellite data, but are limited in temporal and spatial coverage. A combination of the approaches may provide a more accurate indication of temporal and spatial variability of carbon fluxes and ocean saturation of carbonate.
The degree to which seawater is supersaturated with respect to the carbonate minerals (e.g., aragonite) is an important parameter to help document the potential effects of ocean acidification on calcification rate. As ocean acidification continues, the surface ocean aragonite values will decline and will be deleterious to many of the marine calcifiers which precipitate calcium carbonate to build their skeletons. The data developed will provide the baseline for understanding the variability of the nearshore carbon fluxes and carbonate saturation states on the Florida Shelf.
The partnership between USGS and NOAA is developing a regionally specific algorithm coupled to satellite and modeled data sets to generate Florida Shelf fields of air and sea surface pCO2, pCO2 flux, alkalinity, and sea-surface aragonite saturation state. The USGS field campaign will provide regional coverage of the west Florida shelf of carbonate parameters. A robust, and regionally specific algorithm for sea surface alkalinity will enhance the current pCO2 algorithm, originally developed only for the Caribbean. Field data will also be used to link to data collected by the Gordon Gunter cruises to fill-in data gaps. Daily fields of carbon dioxide partial pressure (pCO2,sw) will be calculated by NOAA National Environmental Satellite, Data, and Information Service (NESDIS) through the application of modeled and remotely sensed environmental parameters. The coarse-scale model will be enhanced by the USGS field data and extended to the nearshore zone, for which previously no data existed for calibration of the model.