Hidden Ocean Storms Accelerate Antarctic Ice Melt, Threatening Global Sea Levels

Researchers from the University of California, Irvine (UC Irvine) and NASA's Jet Propulsion Laboratory (JPL) have uncovered previously underestimated "stormlike" circulation patterns beneath Antarctic ice shelves. These powerful subsurface phenomena are driving aggressive melting, with significant implications for global sea level rise projections, according to a recent report by www.enn.com.

The groundbreaking study, published recently in Nature Geoscience on November 18, 2025, is the first to analyze ocean-induced ice shelf melting events on a rapid, day-to-day timescale. This contrasts with previous research that typically focused on seasonal or annual averages, as noted by UC San Diego's Scripps Institution of Oceanography.

These newly identified "ocean storms" are concentrated in critical areas like the Thwaites and Pine Island Glaciers within West Antarctica's Amundsen Sea Embayment. Lead author Mattia Poinelli, a UC Irvine postdoctoral scholar and NASA JPL research affiliate, explained that these submesoscale features push warm water into ice cavities, melting them from below.

The research reveals a concerning positive feedback loop: increased ice shelf melting generates more ocean turbulence, which in turn intensifies further melting. This cycle suggests that the very act of melting creates conditions for even more rapid ice loss, as detailed by Poinelli in the study.

Such ephemeral, high-frequency processes account for nearly a fifth of the total submarine melt variance over an entire seasonal cycle, according to the findings reported by www.enn.com. During extreme events, underwater melting can surge by as much as threefold within hours when these features collide with ice fronts.

The implications are particularly urgent given ongoing climate change, with the West Antarctic Ice Sheet holding the potential to raise global sea levels by up to three meters if it were to collapse entirely. Warmer waters and reduced sea ice coverage could make these energetic submesoscale fronts even more prevalent, as warned by the researchers.

This discovery underscores the critical need for climate models to incorporate these fine-scale oceanic processes for more accurate predictions of future ice loss and sea level rise, a point emphasized by oceanographer Lia Siegelman of UC San Diego's Scripps Institution of Oceanography.

• Background on Antarctic Ice Melt: Antarctica's ice sheets are Earth's largest freshwater reservoir, and their melting significantly contributes to global sea level rise. The West Antarctic Ice Sheet, in particular, is highly vulnerable to warming ocean waters, with glaciers like Thwaites and Pine Island already experiencing rapid thinning, according to antarcticglaciers.org.

• Methodology and Key Findings: The UC Irvine and NASA JPL team utilized advanced climate simulation modeling and moored observation tools to achieve 200-meter-resolution pictures of submesoscale ocean features, which are between 1 and 10 kilometers across. This high-resolution approach allowed them to directly link "ocean storm" activity to intense ice melt, a detail highlighted by www.enn.com.

• Implications for Sea Level Rise Projections: Current climate models often underestimate the contribution of Antarctic ice loss to global sea level rise because they do not fully account for dynamic processes like these "stormlike" patterns. Penn State scientists reported in 2020 that models excluding internal climate variability could delay ice sheet retreat predictions by up to 20 years.

• The Positive Feedback Loop: The study identified a critical feedback mechanism where melting ice shelves create unstable meltwater fronts that intensify these stormlike ocean features. These intensified features then drive even more melting through upward vertical heat fluxes, creating a self-reinforcing cycle that could accelerate ice loss, as explained by Mattia Poinelli.

• Related Research on Ocean-Ice Interactions: Other studies have also pointed to the underestimated role of ocean dynamics. Research published in ScienceDaily in April 2024 revealed that meandering ocean currents interacting with the ocean floor play a significant role in transporting warm water to shallower depths, accelerating basal melting in the Amundsen Sea.

• Broader Climate System Impacts: Melting Antarctic ice sheets are projected to slow the Antarctic Circumpolar Current (ACC), the world's strongest ocean current, by up to 20% by 2050 under high emissions scenarios. This slowdown could allow warmer water to seep closer to ice shelves, further accelerating melt and impacting the ocean's ability to absorb heat and carbon, as reported by The University of Melbourne in March 2025.

• Challenges in Modeling and Future Steps: The complexity of ice-ocean interactions, including evolving sub-ice-shelf cavity geometries and moving grounding lines, poses significant challenges for accurate modeling. Scientists emphasize the need for fully coupled ice-ocean models to improve projections of ice discharge and sea level rise, according to noaa's Geophysical Fluid Dynamics Laboratory.

• Urgency for Policy and Adaptation: Australian Antarctic Division Chief Scientist Prof. Nerilie Abram highlighted at COP30 in November 2025 that multiple abrupt changes are developing across the Antarctic environment, which can be difficult or impossible to reverse. Reducing greenhouse gas emissions to limit global warming is crucial to avoid triggering irreversible impacts, she stated.