Norwegian Sea net community production estimated from O<sub>2</sub> and prototype CO<sub>2</sub> optode measurements on a Seaglider

Abstract. We report on a pilot study using CO2 optode deployed Seaglider in the Norwegian Sea from March to October 2014. The measurements required drift and lag correction situ calibration discrete water samples collected vicinity. found that signal correlated better with concentration of CO2, c(CO2), than its partial pressure, p(CO2). Using calibrated c(CO2) regional parameterisation total alkalinity (AT) as function temperature salinity, we calculated dissolved inorganic carbon content, c(DIC), which had standard deviation 11 µmol kg?1 compared measurements. glider was also equipped an oxygen (O2) optode. O2 corrected c(O2) climatology for deep samples. data enabled calculation DIC- O2-based net community production, N(DIC) N(O2). To derive N, DIC inventory changes over time were combined estimates air–sea gas exchange, diapycnal mixing entrainment deeper waters. Glider-based observations captured two periods increased Chl late spring (May) second one summer (June). For May period, = (21±5) mmol m?2 d?1, N(O2) (94±16) d?1 (uncalibrated) peak craw(Chl a) 3 mg m?3. During June maximum 4 m?3, associated (85±5) (126±25) d?1. high-resolution dataset allowed quantification N before, during after inventory. After remineralisation material produced period decreased (-3±5) (0±2) survey area source sink most summer. deployment different surface waters influenced by Atlantic Current (NwAC) Coastal (NCC). NCC characterised lower c(DIC) NwAC, well but higher N(DIC). Our results show potential simultaneously capture time- depth-resolved variability concentrations.