Carbon chemistry observations in tropical coastal waters

The dataset reports field observations of the carbon composition of seawater at a coral reef lagoon and a mangrove tidal creek in Nusa Penida, Indonesia. Observations include high temporal resolution time series of radon, CO2, and ancillary parameters. Time series observations of radon (30 min intervals) and carbon dioxide (1 min) were performed using automated analysers powered with 12 V batteries. The calibrated radon (RAD-7 Durridge Company) and CO2 (Licor 840) analysers measure gas concentrations in a closed air loop in equilibrium with a stream of flowing water pumped at >3 L per minute into a shower head gas exchanger (Webb et al., 2016 and references therein). Water depths, salinity and temperature were measured using a conductivity-temperature-depth (CTD diver, Van Essen Instruments®) or a Hydrolab sonde (MS5) at time steps ranging from 5 to 30 min. Wind speeds were determined from local meteorological stations. Total alkalinity and dissolved inorganic carbon samples were immediately filtered using combusted 0.7 mm GF/F disposable filters and analysed using a VINDTA 3C (Versatile INstrument for the Determination of Total inorganic carbon and titration Alkalinity). The VINDTA measured TA via Gran titration with a Metrohm Titrino and DIC after sample CO2 extraction with phosphoric acid followed by coulometric titration (McMahon et al., 2018 and references therein).  

References

McMahon, A., Santos, I.R., Schulz, K.G., Cyronak, T. and Maher, D.T.  2018.  Determining coral reef calcification and primary production using automated alkalinity, pH and pCO2 measurements at high temporal resolution. Estuarine, Coastal and Shelf Science 209, 80-88.

Webb, J.R., Maher, D.T. and Santos, I.R.  2016.  Automated, in situ measurements of dissolved CO2, CH4, and δ13C values using cavity enhanced laser absorption spectrometry: Comparing response times of air-water equilibrators. Limnology and Oceanography: Methods 14(5), 323-337.