\n Your contribution helps us keep the service running — and as a thank you, you\'ll receive an Ad-Free Account.\n

\n Learn more about how your donation supports us.\n

edited by Lisa Lock, reviewed by Robert Egan

This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility:

Add as preferred source Overview of the FOCUS study area. Credit: Communications Earth & Environment (2026). DOI: 10.1038/s43247-026-03673-y Ocean currents are not just horizontal motions that flow from side to side. There are also vertical currents that act like deep-sea elevators, pushing heat and carbon down into the deep, while bringing up vital nutrients and dissolved gases to the surface.

Our knowledge of these vertical movements has been limited by a lack of detailed data, but new research published in the journal Communications Earth & Environment is providing new insights into how these hidden currents operate in the Southern Ocean.

Using high-resolution satellite data alongside robotic underwater gliders, scientists have shown that these currents are more violent and reach much deeper than anyone previously realized.

To gather this data, Andrew F. Thompson, a physical oceanographer at the California Institute of Technology (Caltech), and colleagues conducted a five-week cruise in the freezing waters off Australia. The trip was timed to coincide with when a new satellite called SWOT (Surface Water and Ocean Topography) was flying overhead. It measures the height of the ocean surface and can pick out features roughly 10 to 100 kilometers across (about 6 to 60 miles).

The team also deployed autonomous underwater gliders to measure water density, temperature, and salinity. They compared this with satellite data and plugged everything into an ocean model to measure how fast water was moving up or down.

The results revealed an incredibly violent system beneath the surface, driven by ocean whirlpools known as eddies. The vertical currents reach down at least 3,000 feet (1,000 meters) into the deep, and measure just six miles (10 kilometers) across in places. Meanwhile, the water travels up or down at speeds exceeding 330 feet (100 meters) a day.

"Vertical velocities are deep-reaching, have horizontal scales as small as 10 km, and commonly exceed 150 m day-1 throughout the upper 1000 m," commented the research team in their paper.

Knowing more about vertical currents tells us more about how much heat and carbon the oceans are absorbing globally. This should help us predict the pace of future change.

The latest research is based on a specific region of the Southern Ocean, within the Antarctic Circumpolar Current south of Australia. But the authors hope it will eventually improve our estimates of heat and carbon transport across the entire Southern Ocean by better capturing how these vertical flows change over time and influence climate.

"This analysis is a step towards generating temporally-varying vertical tracer fluxes for the circumpolar Southern Ocean."

Written for you by our author Paul Arnold, edited by Lisa Lock, and fact-checked and reviewed by Robert Egan—this article is the result of careful human work. We rely on readers like you to keep independent science journalism alive. If this reporting matters to you, please consider a donation (especially monthly). You'll get an ad-free account as a thank-you.

Andrew F. Thompson et al, The three-dimensional structure of fine-scale, vertical velocities in the Southern Ocean inferred from space, Communications Earth & Environment (2026). DOI: 10.1038/s43247-026-03673-y

Journal information: Communications Earth & Environment

BSc Biology from University of London. BBC documentary producer with world travel experience. Freelances from southern Spain. Full profile

BA art history, MA material culture. Former museum editor, paramedic, and transplant coordinator. Editing for Science X since 2021. Full profile

Bachelor's in mathematical biology, Master's in creative writing. Well-traveled with unique perspectives on science and language. Full profile

High-resolution satellite and underwater glider data reveal that Southern Ocean vertical currents, driven by eddies, extend at least 1,000 meters deep and can exceed 150 meters per day in velocity over horizontal scales as small as 10 kilometers. These findings indicate more intense and deep-reaching vertical transport of heat and carbon than previously recognized, improving understanding of oceanic contributions to global climate regulation.

This summary was automatically generated using LLM. Full disclaimer

Use this form if you have come across a typo, inaccuracy or would like to send an edit request for the content on this page. For general inquiries, please use our contact form. For general feedback, use the public comments section below (please adhere to guidelines).

Please select the most appropriate category to facilitate processing of your request

Thank you for taking time to provide your feedback to the editors.

Your feedback is important to us. However, we do not guarantee individual replies due to the high volume of messages.

Your email address is used only to let the recipient know who sent the email. Neither your address nor the recipient's address will be used for any other purpose. The information you enter will appear in your e-mail message and is not retained by Phys.org in any form.

Get weekly and/or daily updates delivered to your inbox. You can unsubscribe at any time and we'll never share your details to third parties.

We keep our content available to everyone. Consider supporting Science X's mission by getting a premium account.