Method

• Main Authors: Prepared N. Metzl, C. Brunet
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Indian; Southern Ocean; North Atlantic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.505.1493; http://www.obs-vlfr.fr/cd_rom_dmtt/ANTARES/A3/a3_min33_surf_fCO2_metzl_meth.pdf

The sea surface fugacity of CO2 (fCO2) was measured onboard the reasearch vessel Marion-Dufresne (IPEV) during the French JGOFS/ANTARES-3 by C. Brunet and C. Grosbois (LBCM, Paris) in the frame of the project MINERVE-33. The fCO2 measurements technique has been described for other MINERVE cruises conducted during years 1990-1995 in the Indian and Southern Ocean (Poisson et al.,1993; Metzl et al. 1995, 1999). This instrumentation was also used by our group during the international at-sea intercomparison of fCO2 systems conducted in 1996 in the North-Atlantic (Kortzinger et al., 2000). In short, sea surface water is continuously equilibrated using a "thin film " type equilibrator thermostated with surface seawater. The CO2 in the dried gas is measured with a non-dispersive infrared analyser (NDIR, Siemens Ultramat 5F). Standard gases for calibration (269.9, 349.7, 489.6 ppm) and atmospheric CO2 are measured every 7 hours. To correct measurements to in situ data, we used polynomials given by Weiss and Price (1980) for vapour pressure and by Copin-Montégut (1988, 1989) for temperature. On average, the temperature in the thermostated equilibrium cell was 1.00°C warmer than SST during MINERVE-33 cruise. Based on different cruises analysis, the oceanic fCO2 data are accurate