UCI and NASA JPL link Antarctic ice loss to short-term ocean features

Researchers at the University of California, Irvine and NASA’s Jet Propulsion Laboratory report that stormlike circulation patterns beneath Antarctic ice shelves are driving aggressive melting, with implications for global sea level rise projections. In a Nature Geoscience paper published in 2025, the team describes the first examination of ocean-induced ice shelf melting events on the timescale of days, enabling them to match “ocean storm” activity with intense ice melt at Thwaites Glacier and Pine Island Glacier in the Amundsen Sea Embayment in West Antarctica (doi: 10.1038/s41561-025-01831-z).

Using climate simulation modeling and moored observation tools, the researchers resolved submesoscale ocean features 1 to 10 kilometers across at 200-meter resolution. Lead author Mattia Poinelli said these “submesoscales cause warm water to intrude into cavities beneath the ice, melting them from below,” noting that the processes are “ubiquitous year-round in the Amundsen Sea Embayment and represent a key contributor to submarine melting.” The study identifies a positive feedback loop in which more ice shelf melting generates more ocean turbulence, which in turn causes additional melting. “Submesoscale activity within the ice cavity serves both as a cause and a consequence of submarine melting,” Poinelli said, adding that “the melting creates unstable meltwater fronts that intensify these stormlike ocean features, which then drive even more melting through upward vertical heat fluxes.”

The team found that these ephemeral, high-frequency processes account for nearly a fifth of the total submarine melt variance over a seasonal cycle. During extreme events, submarine melting can increase by as much as threefold within hours when these features collide with ice fronts and penetrate beneath the ice base. The numerical findings align with high-resolution observational data from moorings in the vicinity and floats deployed in another sector of Antarctica, which show distinct intermittent events of warming and increased salinity at depths with similar magnitudes and timescales as the extreme melting events described in the study.

Poinelli described the region between the Crosson and Thwaites ice shelves as a “submesoscale hot spot,” where the floating tongue of the Thwaites ice shelf and the shallow seafloor act as a topographic barrier that enhances submesoscale activity. The research suggests that in future scenarios with warmer waters, longer polynya periods, and lower sea ice coverage, these energetic submesoscale fronts could become more prevalent, with implications for ice shelf stability and global sea level rise. The West Antarctic Ice Sheet, if it were to collapse, could raise global sea level by up to 3 meters.

Co-author Yoshihiro Nakayama said that as the model matched observations, “we can go an extra step. We can extrapolate further to say there’s weatherlike storms hitting and melting the ice.” Eric Rignot said the findings highlight the need to fund and develop better observation tools, including advanced oceangoing robots capable of measuring suboceanic processes and associated dynamics. Lia Siegelman contributed to the project, which was funded by NASA’s Cryospheric Sciences Program with support from the NASA Advanced Supercomputing Division.