Home Page | Help | Contact | Log In | Search | Follow us: Official 2012 OSM Twitter Feed Official OSM 2012 Facebook Page

Easley, R. A., University of South Florida, St. Petersburg, FL, USA, reasley@mail.usf.edu
Patsavas, M. C., University of South Florida, St. Petersburg, FL, USA, mpatsava@mail.usf.edu
Liu, X. ., University of South Florida, St. Petersburg, FL, USA, liu@marine.usf.edu
Ding, X. ., University of South Florida, St. Petersburg, FL, USA, xding@marine.usf.edu
Yang, B. ., University of South Florida, St. Petersburg, FL, USA, boyang@mail.usf.edu
Kaltenbacher, E. A., SRI International, St. Petersburg, FL, USA, eric.kaltenbacher@sri.com
Adornato, L. A., SRI International, St. Petersburg, FL, USA, lori.adornato@sri.com
Byrne, R. H., University of South Florida, St. Petersburg, FL, USA, byrne@marine.usf.edu
Greeley, D. ., Pacific Marine Environmental Laboratory/National Oceanic and Atmospheric Administration, Seattle, WA, USA, dana.greeley@noaa.gov
Feely, R. A., Pacific Marine Environmental Laboratory/National Oceanic and Atmospheric Administration, Seattle, WA, ,

EMPIRICAL OPTIMIZATION OF THE SPECTROPHOTOMETRIC MEASUREMENT OF CARBONATE ION IN SEAWATER USING FIELD OBSERVATIONS

Increasing input of anthropogenic carbon dioxide into the oceans is reducing seawater pH and depressing the saturation states of calcium carbonate polymorphs creating a need for frequent direct measurements of oceanic carbonate ion concentrations. To simplify the procedures required for determining carbonate saturation states, a method has been developed for direct spectrophotometric determinations of carbonate ion concentrations in seawater. The measurement protocol involves direct analysis of the ultraviolet absorbance of Pb (II) in seawater. The method utilizes three salinity-dependent, molecularly-based fitting parameters along with formation constants for lead carbonate species from an ensemble of lead chloride species. Empirical models of the fitting parameters were optimized to reduce errors between calculated carbonate ion concentrations and carbonate ion concentrations determined from spectrophotometric measurements of Pb (II) absorbance spectra. Field data collected during a cruise on R/V Wecoma (September 2011) were used to revise fitting parameters. Internal consistency calculations using measurements of pH, alkalinity, and DIC were used to examine the accuracy of the field measurements. This presentation highlights improvements to increase method sensitivity and reproducibility over a range of oceanic conditions.

Poster presentation

Session #:148
Date: 2/22/2012
Time: 17:00 - 18:00
Location: Poster/Exhibit Hall

Presentation is given by student: Yes

PosterID: A0334