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Publication Date
20 February 2023

Antarctic Shelf Ocean Warming and Sea Ice Melt Affected by Projected El Niño Changes

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Subsurface ocean warming over the Antarctic shelf affects melt of ice shelf/sheets with implications for ice sheet stability and future sea level rise. A projected increase in El Niño variability is found to slow future mid-latitude Southern Ocean warming but its impact on Antarctic shelf ocean is unknown


We examine outputs from 31 climate models that participated in Phase 6 of the Coupled Model Intercomparison Project(CMIP6), in which oceanic temperatures and other circulation fields are available. These models are subject to historical forcings before 2014 and a high-emission scenario (SSP5-8.5) for future climate.  Crucially, to demonstrate model credibility, these models simulate the observed feature of the high-latitude southern ocean temperature structure, with warmer ocean temperatures below 200m than that of the surface ocean


We show that a projected increase in El Niño variability slows sea ice reduction but accelerates Antarctic shelf ocean warming, thus hastening ice shelf/sheet melt, with profound implications for contributing to ice sheet instability and possibly accelerating the rate of future sea level rise

Point of Contact
Gerald Meehl
National Center for Atmospheric Research (NCAR)
Funding Program Area(s)