Petermann Glacier drains about 4 percent of the Greenland Ice Sheet as it moves inexorably toward the Arctic Ocean. A new observation and modeling research study reveals that the glacier is more susceptible than previously believed to the invasion of warm ocean water on its underside, resulting in sped up melting and boosting the prospective intensity of future water level rise. Credit: Eric Rignot/ UCIUC Irvine researchers recommend we may be underestimating the severity of water level rise.Researchers at the University of California, Irvine and NASAs Jet Propulsion Laboratory have actually carried out the first massive observation and modeling research study of northwest Greenlands Petermann Glacier. Their findings expose the intrusion of warm ocean water underneath the ice as the culprit in the accelerated melting it has actually experienced considering that the turn of the century, and their computer system predictions indicate that potential sea level increase will be much even worse than previously estimated.For a paper published recently in Geophysical Research Letters, the UCI-led team utilized radar interferometry information from a number of European satellite objectives to map the tidal movement of Petermann Glacier and the Massachusetts Institute of Technologys general calculation model to approximate the impact of climate change in a complex environment including ice, seawater, and land, all of which are under the impact of tides and environment change-driven temperature boosts.Advances in Glacier-Ocean Interaction Understanding”Satellite information exposed that the glacier shifts by several kilometers– or thousands of feet– as tides change,” stated lead author Ratnakar Gadi, UCI Ph.D. candidate in Earth system science. “By factoring this migration into the MIT numerical ocean design, we were able to approximate approximately 140 meters [460 feet] of thinning of the ice in between 2000 and 2020. Typically, the melt rate has actually increased from about 3 meters per year in the 1990s to 10 meters per year in the 2020s.”Senior co-author Eric Rignot, UCI professor of Earth system science, said that this and other research studies carried out by his team recently have caused a basic shift in polar ice scientists thinking of ocean and glacier interactions.”For a very long time, we considered the transition border between ice and ocean to be sharp, but its not, and in fact it diffuses over a really large zone, the grounding zone, which is numerous kilometers wide,” said Rignot, who is also a senior research scientist at NASA JPL. “Seawater falls and increases with modifications in oceanic tides in that zone and melts grounded ice from listed below vigorously.”Gadi said the design forecasted that melt rates will be greatest near the mouth of the grounding zone cavity and higher than anywhere else in the ice shelf cavity. Warmer water and higher seawater intrusion below the ice discusses the observed thinning along Petermanns central flowline.According to the research study, the extended shape of the grounding zone cavity is a significant factor to accelerated ice melting. In a run of the numerical model considering simply warmer ocean temperature, the group found thinning of about 40 meters. In a 2nd modeling workout, a boost in the grounding zone cavity from 2 to 6 kilometers was included, and because case, ice thinning grew to 140 meters.Implications for Future Sea Level Rise Projections”These modeling results conclude that modifications in grounding zone lengths increase melt more significantly than warmer ocean temperatures alone,” Gadi said.The scientists kept in mind that grounding zone ice melt decreases the resistance glaciers experience when flowing toward the sea, speeding their retreat. The researchers stated this is a crucial factor used in predicting the intensity of future sea level rise.”The results released in this paper have significant implications for ice sheet modeling and projections of sea level increase,” Rignot stated. “Earlier mathematical studies showed that consisting of melt in the grounding zone would double the forecasts of glacier mass loss. The modeling work in this study validates these fears. Glaciers melt much faster in the ocean than presumed previously.”Reference: “Modeling Ice Melt Rates From Seawater Intrusions in the Grounding Zone of Petermann Gletscher, Greenland” by R. Gadi, E. Rignot and D. Menemenlis, 22 December 2023, Geophysical Research Letters.DOI: 10.1029/ 2023GL105869Joining Rignot and Gadi on this project was Dimitris Menemenlis, NASA JPL research scientist. The work was performed under a grant by NASAs Cryospheric Sciences Program.
Their findings expose the invasion of warm ocean water beneath the ice as the culprit in the sped up melting it has actually experienced since the turn of the century, and their computer system predictions suggest that possible sea level rise will be much worse than formerly estimated.For a paper released just recently in Geophysical Research Letters, the UCI-led team used radar interferometry information from numerous European satellite objectives to map the tidal motion of Petermann Glacier and the Massachusetts Institute of Technologys basic estimation model to approximate the effect of climate modification in a complicated environment including ice, land, and seawater, all of which are under the influence of tides and climate change-driven temperature level boosts.Advances in Glacier-Ocean Interaction Understanding”Satellite information revealed that the glacier shifts by several kilometers– or thousands of feet– as tides alter,” stated lead author Ratnakar Gadi, UCI Ph.D. prospect in Earth system science.”For a long time, we thought of the shift border in between ice and ocean to be sharp, but its not, and in fact it diffuses over an extremely wide zone, the grounding zone, which is numerous kilometers broad,” stated Rignot, who is likewise a senior research study researcher at NASA JPL. Warmer water and greater seawater invasion beneath the ice describes the observed thinning along Petermanns central flowline.According to the study, the extended shape of the grounding zone cavity is a significant contributor to accelerated ice melting. In a second modeling workout, a boost in the grounding zone cavity from 2 to 6 kilometers was consisted of, and in that case, ice thinning grew to 140 meters.Implications for Future Sea Level Rise Projections”These modeling results conclude that modifications in grounding zone lengths increase melt more substantially than warmer ocean temperatures alone,” Gadi said.The researchers kept in mind that grounding zone ice melt decreases the resistance glaciers experience when flowing toward the sea, speeding their retreat.
