The seasonal and interannual variations of carbon dioxide flux in the tropical Atlantic were investigated from 1994-2023 based on 30 years of sea surface carbon dioxide fugacity (fCO2ssw) data available in the latest version of the Surface Ocean CO2 Atlas (SOCATv24). Using monthly mean global atmospheric CO2 at Mauna Loa, CO2 exchange between the ocean and atmosphere was calculated. The long-term trend across the tropical Atlantic investigated here showed the influence of sea surface temperature, salinity, and ocean surface CO2 content on this region’s interannual variability of CO2 flux. Correlation statistics revealed that ocean surface CO2 content has the greatest influence, where 20 years of data show significant correlations (r-value ≥ 0.5), and ocean surface temperature has the lowest effect. This study showed salinity as the main factor controlling CO2 uptake demonstrating a significantly positive correlation for eleven of the studied years, and a negative correlation for nine years. Thus, higher salinity decreases and increases CO2 uptake for the different years respectively. This finding highlights biogeochemical complexity of the interaction between salinity and CO2 uptake on long-term variability and carbon sink capacity in the tropical Atlantic Ocean.
Cite this paper
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