Derivation of seawater pCO2 from net community production identifies the South Atlantic Ocean as a CO2 source

Ford, Daniel J.; Tilstone, Gavin H.; Shutler, Jamie D.; Kitidis, Vassilis

doi:https://doi.org/10.5194/bg-19-93-2022

Articles | Volume 19, issue 1

https://doi.org/10.5194/bg-19-93-2022

© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/bg-19-93-2022

© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 19, issue 1

Research article

|

06 Jan 2022

Research article |

| 06 Jan 2022

Derivation of seawater pCO₂ from net community production identifies the South Atlantic Ocean as a CO₂ source

Daniel J. Ford, Gavin H. Tilstone, Jamie D. Shutler, and Vassilis Kitidis

Data sets

Interpolated Global surface ocean carbon dioxide partial pressure and ocean-atmosphere fluxes 1992–2018, corrected for surface temperature deviations A. J. Watson, U. Schuster, J. D. Shutler, T. Holding, I. G. C. Ashton, P. Landschützer, D. K. Woolf, and L. Goddijn-Murphy https://doi.org/10.1594/PANGAEA.922985

Interpolated surface ocean carbon dioxide partial pressure for the South Atlantic Ocean (2002–2018) using different biological parameters D. Ford, G. H. Tilstone, J. D. Shutler, and V. Kitidis https://doi.org/10.1594/PANGAEA.935936

MODIS-Aqua Level 3 Mapped Chlorophyll Data Version R2018.0 NASA OBPG https://doi.org/10.5067/AQUA/MODIS/L3M/CHL/2018

MODIS-Aqua Level 3 Mapped Photosynthetically Available Radiation Data Version R2018.0 NASA OBPG https://doi.org/10.5067/AQUA/MODIS/L3M/PAR/2018

MODIS Aqua Level 3 SST Thermal IR Daily 4km Daytime v2014.0 NASA OBPG https://doi.org/10.5067/MODSA-1D4D4

Copernicus Marine Modelling Service global ocean physics reanalysis product (GLORYS12V1) CMEMS https://doi.org/10.48670/moi-00021

ERA5 monthly averaged data on single levels from 1979 to present H. Hersbach, B. Bell, P. Berrisford, G. Biavati, A. Horányi, J. Muñoz Sabater, J. Nicolas, C. Peubey, R. Radu, I. Rozum, D. Schepers, A. Simmons, C. Soci, D. Dee, and J.-N. Thépaut https://doi.org/10.24381/cds.f17050d7

Short summary

This study identifies the most accurate biological proxy for the estimation of seawater pCO₂ fields, which are key to assessing the ocean carbon sink. Our analysis shows that the net community production (NCP), the balance between photosynthesis and respiration, was more accurate than chlorophyll a within a neural network scheme. The improved pCO₂ estimates, based on NCP, identified the South Atlantic Ocean as a net CO₂ source, compared to a CO₂ sink using chlorophyll a.