Satellite data reveal Southern Ocean vertical currents diving 3,000 feet below surface

June 9, 2026 report Satellite data reveal Southern Ocean vertical currents diving 3,000 feet below surface Paul Arnold Author Lisa Lock Scientific Editor Robert Egan Associate Editor 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. Combining satellite and subsurface data 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. Fast-moving currents 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. Tracking heat and carbon 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. Publication details 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 © 2026 Science X Network