Continental shelves as a variable but increasing global sink for atmospheric carbon dioxide.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 29386510.
- Also identified by DOI 10.1038/s41467-017-02738-z and PMC identifier 5792465.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
It has been speculated that the partial pressure of carbon dioxide (pCO<sub>2</sub>) in shelf waters may lag the rise in atmospheric CO<sub>2</sub>. Here, we show that this is the case across many shelf regions, implying a tendency for enhanced shelf uptake of atmospheric CO<sub>2</sub>. This result is based on analysis of long-term trends in the air-sea pCO<sub>2</sub> gradient (ΔpCO<sub>2</sub>) using a global surface ocean pCO<sub>2</sub> database spanning a period of up to 35 years. Using wintertime data only, we find that ΔpCO<sub>2</sub> increased in 653 of the 825 0.5° cells for which a trend could be calculated, with 325 of these cells showing a significant increase in excess of +0.5 μatm yr<sup>-1</sup> (p < 0.05). Although noisier, the deseasonalized annual data suggest similar results. If this were a global trend, it would support the idea that shelves might have switched from a source to a sink of CO<sub>2</sub> during the last century.