Using gliders to fill in time/space gaps in carbon export estimates

Carbon export out of the surface ocean, estimated as Net Community Production (NCP),  regulates the transfer of carbon dioxide across the sea surface and thus atmospheric CO2 concentration. Accurate NCP estimates in productive coastal regions often require constraints on vertical transport and precise measurements of the O2/Ar ratio to remove the influence of bubbles from wave activity, but because sophisticated sampling and measurement techniques are required to make these measurements, they are often limited in spatiotemporal resolution. However, small‐scale patchy export may be a significant contributor to the overall carbon sink, thus high‐resolution estimates of NCP may be necessary to constrain carbon export in dynamic regions.

In a recent publication in JGR-Oceans, my colleagues and I have demonstrated that we can use dissolved oxygen measurements made by an autonomous buoyancy-driven glider and an empirical relationship derived from discrete O2/Ar in the surface mixed layer to obtain high-resolution estimates of NCP in coastal Southern California. Our results show that bubble injection accounted for ~25% of the oxygen signal and reveal higher‐frequency variability that discrete sampling was unable to resolve, suggesting that this approach may be useful in other regions with well‐constrained vertical transport rates.