Constraining Southern Ocean CO2 Flux Uncertainty Using Uncrewed Surface Vehicle Observations
By Adrienne J. Sutton, Nancy Louise Williams and Bronte David Tilbrook
The Southern Ocean is an important part of the global climate, playing an outsized role in the uptake of heat and carbon. Yet observing the Southern Ocean is challenging due to its size, remoteness, and harsh conditions. In 2019 we completed the first autonomous circumnavigation of Antarctica with an Uncrewed Surface Vehicle (USV), also known as an ocean robot, in order to address some of these observing challenges. By directly measuring air and surface seawater carbon dioxide (CO2) and wind speed on the USV, we were able to observe CO2 exchange between the ocean and atmosphere every hour during the mission. Using this data set, we estimated potential errors in these measurements as well as other approaches to estimating CO2 exchange. The use of different satellite-based wind products and sampling frequency play the largest role in uncertainty of the uptake of CO2 in the Southern Ocean. In order to reduce this uncertainty and provide a better understanding of the Southern Ocean, expansion of an observing network made up of ships, USVs, and other autonomous devices is necessary.
The full article appeared on the ESSOAR website at https://www.essoar.org/doi/10.1002/essoar.10505700.1]]>