Developments in marine pCO2 measurement technology; towards sustained in situ observations
TrAC - Trends in Analytical Chemistry
Open access under a Creative Commons license: https://creativecommons.org/licenses/by/4.0/
The oceanic uptake of anthropogenic CO2 causes pronounced changes to the marine carbonate system. High quality pCO2 measurements with good temporal and spatial coverage are required to monitor the oceanic uptake, identify regions with pronounced carbonate system changes, and observe the effectiveness of CO2 emission mitigation strategies. There are currently several instruments available, but many are unsuitable for autonomous deployments on in situ platforms such as gliders, moorings and Argo floats. We assess currently available technology on its suitability for in situ deployment, with a focus on optode technology developments. Optodes for pCO2 measurements provide a promising new technological approach, and were successfully calibrated over the range of 280–480 μatm applying modified time-domain dual lifetime referencing. A laboratory precision of 0.8 μatm (n = 10) and a response time (τ90) of 165 s were achieved, and with further development pCO2 optodes may become as widely used as their oxygen counterparts.
This research was supported by the Analytical Chemistry Trust Fund which has been established by the Royal Society for Chemistry and the Natural Environment Research Council; grant number NE/I019638/1.
This is the final version of the article. Available from Elsevier via the DOI in this record.
Vol. 88, pp. 53 - 61