In situ measurement of dissolved inorganic carbon speciation in natural waters, pH, pC02, TA, & TC02, Honolulu, Hawaii, February 16-18, 2005: workshop proceedings

The Alliance for Coastal Technology (ACT) convened a workshop on the in situ measurement ofdissolved inorganic carbon species in natural waters in Honolulu, Hawaii, on February 16, 17, and18, 2005. The workshop was designed to summarize existing technologies for measuring theabundance and speciation of dissolved inorganic carbon and to make strategic recommendationsfor future development and application of these technologies to coastal research and management.The workshop was not focused on any specific technology, however, most of the attention of theworkshop was on in situ pC02 sensors given their recent development and use on moorings forthe measurement of global carbon fluxes. In addition, the problems and limitations arising fromthe long-term deployment of systems designed for the measurement of pH, total dissolvedinorganic carbon (DIC), and total alkalinity (TA) were discussed. Participants includedresearchers involved in carbon biogeochemistry, industry representatives, and coastal resourcemanagers. The primary questions asked during the workshop were:I. What are the major impediments to transform presently used shipboard pC02 measurementsystems for use on cost-eficient moorings?2. What are the major technical hurdles for the in situ measurement of TA and DIC?3. What specific information do we need to coordinate efforts for proof of concept' testing ofexisting and new technologies, inter-calibration of those technologies, better softwaredevelopment, and more precise knowledge quantzjjing the geochemistry of dissolvedinoeanic carbon species in order to develop an observing system for dissolved inorganiccarbon?Based on the discussion resulting from these three questions, the following statements weremade:Statement No. 1Cost-effective, self-contained technologies for making long-term, accurate measurements of thepartial pressure of C02 gas in water already exist and at present are ready for deployment onmoorings in coastal observing systems.Statement No. 2Cost-effective, self-contained systems for the measurement of pH, TA, and DIC are still neededto both fully define the carbonate chemistry of coastal waters and the fluxes of carbon betweenmajor biogeochemical compartments (e.g., air-sea, shelf-slope, water column-sediment, etc.). (pdf contains 23 pages)

NOAA

Alliance for Coastal Technologies, CBL/UMCES