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Liu, X. ., University of South Florida, St. Petersburg, USA, liu@marine.usf.edu
Byrne, R. H., University of South Florida, St. Petersburg, USA, byrne@marine.usf.edu
Yates, K. K., USGS, St. Petersburg, USA, kyates@usgs.gov
Kaltenbacker, E. A., SRI, St. Petersburg, USA, eric.kaltenbacher@SRI.com
Adornato, L. ., SRI, St. Petersburg, USA, Lori.Adornato@sri.com

IN-SITU SPECTROPHOTOMETRIC MEASUREMENT OF DISSOLVED INORGANIC CARBON IN A BIOFOULING-PRONE REGION

An automated spectrophotometric procedure for in situ DIC analysis is described. Based on use of a Teflon AF liquid core waveguide (LCW) as both the optical cell and equilibration membrane, an acidified seawater sample outside the LCW is equilibrated with an inner LCW solution that has a known alkalinity. DIC is then calculated from measured pH within the LCW and the known alkalinity within the LCW. The instrument was tested within a high productivity area of Florida Bay, with a once per minute sampling rate. DIC measurement results show that the method is capable of accurate measurements with high temporal resolution sampling. Furthermore, the measurement chemistry, combing acidified external seawater samples with a clean, synthetic internal solution, provides a biofouling-resistant protocol for long term monitoring of DIC in natural waters. When combined with spectrophotometric pH and pCO2 on the same platform, the DIC measurement procedure allows full characterization of the marine CO2 system with high spatial and temporal resolution.

Session #:148
Date: 2/21/2012
Time: 14:15
Location: Room 151

Presentation is given by student: No