%0 conference paper
%@ 
%A Macovei, V.,Voynova, Y.,Becker, M.,Triest, J.,Petersen, W.

%D 2021
%J Advances in operational oceanography : expanding Europe's ocean observing and forecasting capacity : Proceedings of the 9th EuroGOOS International Conference
%N 
%P 30-33 
%R doi:10.13155/83160
%T An instrument intercomparison exercise in the Skagerrak allows extending the FerryBox pCO2 observational coverage across the Central and Southern North Sea
%U https://doi.org/10.13155/83160
 
%X The  partial  pressure  of  carbon  dioxide  (pCO2)  in  surface  seawater  is  an  important,biogeochemical variable, influencing the direction of air–sea carbon dioxide exchange.,Large-scale observations of pCO2 are facilitated by Ships-of-Opportunity (SOOP-CO2),equipped with underway measuring instruments that are becoming more autonomous.,Here we performed a comparison between a FerryBox-integrated membrane-based,sensor and a showerhead equilibration sensor installed on two SOOP-CO2 between,2013 and 2018. We identified time- and space-adequate crossovers in the Skagerrak,Strait, where the two ship routes often crossed. We found a mean total difference of,1.5 ± 10.6 μatm and a root mean square error of 11 μatm. The pCO2 values recorded,by the two instruments showed a strong linear correlation with a coefficient of 0.91,and a slope of 1.07 (± 0.14), despite the dynamic nature of the environment and,the difficulty of comparing measurements from two different vessels. We showed,the strength of having a sensor-based network with a high spatial coverage that can,be  cross-checked  against  conventional  SOOP-CO2  methods.  Validating  membrane-based sensors and using the expanded coverage and higher frequency measurements,they provide can enable a thorough characterization of pCO2 variability in both open,oceans and dynamic coastal seas.