Eos: Ship-based measurements overestimate S.O. carbon sink

Nov. 25, 2019

An Eos article details work by SOCCOM researchers to reconcile ship- and float-based estimates of the Southern Ocean carbon sink:
 

Ship-Based Measurements Overestimate Southern Ocean Carbon Sink

New research suggests that combining ship- and float-based observations provides a more accurate measure of how much carbon the Southern Ocean absorbs.

SOURCE: Global Biogeochemical Cycles

Accounting for carbon sinks and sources around the world is critical for scientists and policy makers looking to quantify Earth’s carbon budget and stave off the most catastrophic effects of climate change. The Southern Ocean absorbs roughly 40% of the 2.6 petagrams of anthropogenic carbon that dissolves into the global ocean each year, according to current estimates, making it one of the planet’s most vital sinks. But it’s also undersampled.

Researchers typically quantify the movement of carbon dioxide between the atmosphere and the sea by measuring the partial pressure of carbon dioxide in ocean surface waters with instruments on ships or moorings. These shipboard observations are accurate but sparse, with most data collected in the Northern Hemisphere in summer.

To get a more complete estimate of Southern Ocean carbon exchange, Bushinsky et al. combined shipboard measurements with data collected by biogeochemical profiling floats deployed by the Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) project. [read more]

Cited article:

Bushinsky, S. M., Landschützer, P., Rödenbeck, C., Gray, A. R., Baker, D., Mazloff, M. R., et al. ( 2019). Reassessing Southern Ocean air‐sea CO2 flux estimates with the addition of biogeochemical float observations. Global Biogeochemical Cycles, 33. https://doi.org/10.1029/2019GB006176