JUL 31, 2024

Southern Ocean CO2 Absorption Underestimated

WRITTEN BY: Laurence Tognetti, MSc

The Southern Ocean, also called the Antarctic Ocean, is responsible for absorbing carbon dioxide produced by human activities and regulating Earth’s entire climate. While this absorption can function at moderate levels, a recent study published in Science Advances investigates the amount of carbon dioxide that Southern Ocean absorbs and whether these levels can help, or hurt, regulating Earth’s climate. This study holds the potential to help researchers, climate scientists, and the public better understand the impact of climate change has on the Southern Ocean, thus potentially resulting is mis-regulating the climate, overall.

For the study, the researchers directly measured the air-to-sea carbon dioxide flux among resulting in seven separate datasets and compared the findings to prior hypotheses pertaining to the amount of flux that was occurring in the Southern Ocean. As part of the study, the researchers used a new sampling method known as eddy covariance, which involves measuring fluxes directly from the ship’s foremast, or the mast nearest the front of the ship.

A carbon dioxide flux system on the foremast of the RRS Sir David Attenborough during an Antarctica research cruise in 2024. (Credit: Tom Bell/PML)

In the end, the researchers found that the flux is 25 percent higher than prior estimates, with the researchers quick to note this could be explained by changes in temperature in the upper portions of the Southern Ocean. However, they also note these results could be from sampling intervals, along with noting current models used for the study don’t have short-term bursts of carbon dioxide in their algorithms, as well.

“Accurate quantification of the Southern Ocean CO2 sink is essential for the assessment of the Earth’s climate,” said Dr. Yuanxu Dong, who is from the GEOMAR Helmholtz Centre for Ocean Research Kiel and is lead author of the study. “However, it is the most uncertain region regarding the estimate of its CO2 sink capacity. Our study reduces this uncertainty and improves the understanding of Southern Ocean CO2 uptake, and we recommend that future estimates should include temperature adjustments and higher resolution reconstruction and modelling.”

What new discoveries between carbon dioxide and the Southern Ocean will researchers make in the coming years and decades? Only time will tell, and this is why we science!

As always, keep doing science & keep looking up!

Sources: Science Advances, EurekAlert!