Fig 2. Seawater pCO2 calculated from CT and AT, compared with three other methods: 1) spectrophotometric pHT and AT (n = 25), 2) electrode pHNBS and AT (n = 25), and 3) the direct measurement of seawater CO2 with a NDIR CO2 equilibrator (n = 23); a) for pCO2 data and b) for the difference in pCO2 compared to pCO2 derived from CT and AT (delta pCO2).
