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Constraining Southern Ocean CO2 flux uncertainty using uncrewed surface vehicle observations

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journal contribution
posted on 2023-05-21, 11:21 authored by Sutton, AJ, Williams, NL, Bronte TilbrookBronte Tilbrook

Remote, harsh conditions of the Southern Ocean challenge our ability to observe the region’s influence on the climate system. Southern Ocean air-sea CO2 flux estimates have significant uncertainty due to the reliance on limited ship-dependent observations in combination with satellite-based and interpolated data products. We utilize a new approach, making direct measurements of air-sea CO2, wind speed, and surface ocean properties on an Uncrewed Surface Vehicle (USV). In 2019, the USV completed the first autonomous circumnavigation of Antarctica providing hourly CO2 flux estimates. Using this unique data set to constrain potential error in different measurements and propagate those through the CO2 flux calculation, we find that different wind speed products and sampling frequencies have the largest impact on CO2 flux estimates with biases that range from −4% to +20%. These biases and poorly constrained interannual variability could account for discrepancies between different approaches to estimating Southern Ocean CO2 uptake.


Publication title

Geophysical Research Letters



Article number









Institute for Marine and Antarctic Studies


Amer Geophysical Union

Place of publication

2000 Florida Ave Nw, Washington, USA, Dc, 20009

Rights statement

Copyright 2021 The Authors. This article has been contributed to by US Government employees and their work is in the public domain in the USA. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Repository Status

  • Open

Socio-economic Objectives

Antarctic and Southern Ocean oceanic processes

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