Cause of rise was ocean warming of less than 2C, which has major implications for future, researchers warn, Last modified on Thu 13 Feb 2020 01.16 GMT. Views expressed here do not necessarily reflect those of ScienceDaily, its staff, its contributors, or its partners. Ice melt projections may underestimate Antarctic contribution to sea level rise. The Antarctic ice sheet is a complex system, and modeling how it will evolve under future climate conditions requires thousands of simulations and large amounts of computing power. It is not intended to provide medical or other professional advice. . To study the effects of internal climate variability, the researchers analyzed two large ensembles of climate simulations. 7 b). The meltwater CRFs presented here strongly suggest that interactive Antarctic ice melt should be included in climate models. 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Rex Had Huge Growth Spurts, but Other Dinos Grew Slow and Steady, Geoscientists Discover Ancestral Puebloans Survived from Ice Melt in New Mexico Lava Tubes. They used some shallow drilling to take ice samples from the surface. Antarctica logs hottest temperature on record with a reading of 18.3C. This figure shows the Japanese Aerospace Exploration Agency (JAXA) Advanced Microwave Scanning Radiometer 2 (AMSR2) sea ice concentration for Antarctic … Vol. It melted. Financial support for ScienceDaily comes from advertisements and referral programs, where indicated. The orange line shows Penn State. Mass melting of the West Antarctic ice sheet, driven by warmer ocean temperatures, was a major cause of extreme sea level rise more than 100,000 years ago, according to new research. The team, led by scientists at the University of NSW, examined the cause of high sea levels during a period known as the last interglacial, which occurred 129,000-116,000 years ago. Blue ice areas are created by katabatic winds. Melting of the Antarctic ice sheet will cause sea level rises of about two and a half metres around the world, even if the goals of the Paris agreement are met, research has shown. Future climate response to Antarctic Ice Sheet melt caused by … A researcher holds ancient air trapped as gas bubbles within ice. Materials provided by Penn State. Professor of Science in the Department of Earth and Planetary Sciences. (), as shown in Fig. Instead of averaging the results of each ensemble, the scientists fed the atmospheric and oceanic data representing this variability into a three-dimensional Antarctic ice sheet model. Chii-Yun Tsai, Chris E. Forest, David Pollard. "Every bit adds on to the storm surge, which we expect to see during hurricanes and other severe weather events, and the results can be devastating.". “A reduction in the buttressing effect of ice shelves is a negative feedback that can lead to glacial acceleration and a … "Our findings shed new light on one area of uncertainty, suggesting climate variability has a significant impact on melting ice sheets and sea level rise.". "Ice melt projections may underestimate Antarctic contribution to sea level rise." “This has been a big concern and is what the concern is in the present day,” Turney said. Additionally, for years, the IPCC reports have been looking at sea level rise without considering this additional variability and have been underestimating what the impact may be," Forest said. Antarctic sea ice extent likely reached its annual minimum on February 20 and 21, 2020. But the Antarctic Ice Sheet comprises enough mass to contribute 58 meters (190 feet) of sea level rise if it were to melt out completely — enough … ScienceDaily, 9 October 2020. “So the question is how much could fall into the ocean and this is where the last interglacial [period] is so important.”. To trace Antarctica’s potential contribution to this sea-level rise, the scientists travelled to West Antarctica to the Patriot Hills Blue Ice Area, which is on the periphery of the West Antarctic ice sheet. Fluctuations in the weather can have a significant impact on melting Antarctic ice, and models that do not include this factor can underestimate … Accounting for climate variability caused models to predict an additional 2.7 to 4.3 inches -- 7 to 11 centimeters -- of sea level rise by 2100, the scientists recently reported in the journal Climate Dynamics. Wed 12 Feb 2020 18.30 EST Last modified on Wed 12 Feb 2020 20.16 EST Mass melting of the West Antarctic ice sheet, driven by warmer ocean temperatures, was a … Penn State. Scientists have been more concerned about West Antarctica, where the ice has been melting faster in recent years, Rignot said. However, that process smooths out peaks caused by climate variability and reduces the average number of days above temperature thresholds that can impact the ice sheet melt, creating a bias in the results, the scientists said. Global sea levels have risen 0.55 inches since 2003 due to ice melt in Antarctica and Greenland driven by climate change according to new data measurements from several NASA satellites. Their study finds that melting of the West Antarctic ice sheet caused a sea-level rise of more than three metres and it took less than 2C of ocean warming for that to occur. "If we include variability in the simulations, we are going to have more warm days and more sunshine, and therefore when the daily temperature gets above a certain threshold it will melt the ice," Forest said. “That’s the really exciting part of this,” said Mitrovica, the Frank B. Baird Jr. "If we're just running with average conditions, we're not seeing these extremes happening on yearly or decadal timescales.". (2020, October 9). Citation: Shift in atmospheric rivers could affect Antarctic sea ice, glaciers (2020, November 23) retrieved 29 November 2020 from This document is subject to copyright. Climate Change May 4, 2020 - by Tim Lydon In February 2020, along with record-breaking high temperatures in the region, satellite images showed that the surface of the largest remaining ice shelf on the Antarctic Peninsula was experiencing a lot of melt. Citation: Satellite record gives unprecedented view of Antarctic ice shelf melt pattern over 25 years (2020, August 13) retrieved 25 November He said the research also suggested this mass melting happened quite early during the ocean warming “somewhere between zero and 2C”. The question of what caused the Antarctic ice sheet to melt so rapidly during this warming period had been a longstanding enigma. "This additional ice melt will impact the hurricane storm surges across the globe. Fluctuations in the weather can have a significant impact on melting Antarctic ice, and models that do not include this factor can underestimate the global impact of sea level rise, according to Penn State scientists. Even in frigid Antarctica, summer warmth can turn ice into water. Questions? In this study, the researchers used what they called “horizontal ice core” analysis, which involved simply walking across the valley towards the mountain. Penn State. Original written by Matthew Carroll. S. Sadai et al. “If Alaska were covered by 1-meter thick ice, 20% of Alaska would be gone,” explained Igor Polyakov, co-author and oceanographer at the University of Alaska Fairbanks’ International Arctic Research Center and Finnish Meteorological Institute. 585, September 24, 2020, p. 538. doi: 10.1038/s41586-020-2727-5. ScienceDaily shares links with sites in the. A research team, led by scientists at the University of New South Wales, examined the cause of high sea levels during a period known as the last interglacial, which occurred 129,000-116,000 years ago. He said the team’s research could be used to focus on which sections of West Antarctica are most vulnerable to the current climate crisis. Note: Content may be edited for style and length. The study’s lead author Chris Turney is a climate change and earth scientist at UNSW. "It's important to better understand these processes contributing to the additional ice loss because the ice sheets are melting much faster than we expected.". Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. “It means that a large part of the west Antarctic almost certainly disappeared in the last interglacial. Using archived Turney said the current summer in Australia alone had shown the dangers of a warming world just at 1C. At the peak of the 2019-2020 melt season, jewel-toned ponds of meltwater spanned a vast area on the George VI ice shelf—a huge slab of floating glacier ice attached to the western side of the Antarctic Peninsula. Ice melt projections may underestimate Antarctic contribution to sea level rise Date: October 9, 2020 Source: Penn State Summary: Or view hourly updated newsfeeds in your RSS reader: Keep up to date with the latest news from ScienceDaily via social networks: Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Because of this, modelers test how the ice will respond using a mean temperature found by averaging the results of climate models. The record in recent decades for the highest level of ice to melt in Antarctica in one day was reached on Christmas Eve, data suggests. Ice shelves are the gatekeepers for glaciers flowing from Antarctica toward the ocean. "We know ice sheets are melting as global temperatures increase, but uncertainties remain about how much and how fast that will happen," said Chris Forest, professor of climate dynamics at Penn State. Content on this website is for information only. Shift in atmospheric rivers could affect Antarctic sea ice, glaciers Date: November 23, 2020 Source: American Geophysical Union Summary: The National Science Foundation and the Penn State Center for Climate Risk Management funded this research. The paper says ocean temperatures during the last interglacial were likely up to 2C warmer than they are today and global sea levels were 6-9 metres higher. Plain Language Summary Climate models do not capture recent Southern Ocean (SO) climate trends of surface cooling, freshening, and sea ice expansion. Through isotope measurements, they found a gap in the ice sheet record immediately prior to the last interglacial. This ice shelf has existed for at least 10,000 years, and soon it will be gone.” The data for the study was collected by aircraft which measure ice surface elevations and bedrock depths and space-based “synthetic aperture radars” that have been operating since 1997. We now assess parameterized melt rate patterns for the entire Antarctic ice sheet in comparison to the observational melt patterns from Rignot et al. (accessed December 2, 2020). Antarctic ice melt related to tropical weather shifts: Study by Gloria Dickie on 1 April 2020 Scientists predominantly believe that the tropics have the largest influence on global weather. AGU Blogosphere: From a Glacier’s Perspective (2020, February 17) Record Antarctic Temperatures in Feb. 2020 Impact on Eagle Island Ice Cap. A lot of Antarctic research involves deep ice core drilling to study years of climate history. The chaotic nature of the climate system causes each member to yield slightly different responses, and this represents internally generated variability, the scientists said. Antarctica: Too Big to Melt A summer of extremes leaves sobering questions about the state of Earth’s largest store of ice, capable of inundating coastlines worldwide as it melts. ScienceDaily. "Ice melt projections may underestimate Antarctic contribution to sea level rise." “As you walk towards the mountain, you walk over increasingly older ice,” Turney said. May 28, 2020 May 28, 2020 A new study in the journal Science found that floating ice shelves can melt much more rapidly than previously thought—at a rate of about six miles per year. AGU Blogosphere: From a Glacier’s Perspective (2020, February 19) Boydell Glacier Accumulation Zone Rapid Melt Feature Development February 2020. Large ensembles are generated by starting each member with slightly different initial conditions. “Ocean-driven melting at the base of ice shelves is already the main contributor to mass loss from the Antarctic ice sheet,” he said. Extensive parts of the ice sheet are in contact with ocean water, and previous studies have suggested that warming oceans could cause large chunks to break away. Anomalous high temperatures were recorded across Antarctica throughout the summer of 2019/2020, leading to melting of ice and exposure of new ice‐free areas. 7a. He said the West Antarctic was particularly vulnerable to ocean warming because it sits mostly on the sea bed, rather than on land. The Patriot Hills Blue Ice Area, in the Antarctic, where a research team discovered high sea levels during the last interglacial period were due to a rise of less than 2C in ocean temperature. ScienceDaily. Figure 1: 10-year averages between 1979 and 2018 and yearly averages for 2007, 2012, and 2020 of the daily (a) ice extent and (b) ice area in the Northern Hemisphere and a listing of the extent and area of the current, historical Sea ice waxes and wanes with the seasons, but minimum and maximum extents rarely match from year to year; over years and decades, summer and winter extents vary. They found atmospheric variations had a larger and more immediate impact on the ice sheet, but ocean variability was also a significant factor. (a) Monthly mean anomaly (the difference from climatological monthly mean) of 2 m air temperature from NCEP/NCAR Reanalysis 1 data (Kalnay et al., 1996 ) for November 2019 to February 2020. Antarctic sea ice extent for February 20 and 21, 2020 was 2.69 million square kilometers (1.04 million square miles). Have any problems using the site? Countries have signed on to the Paris agreement which aims to keep global heating below 2C. But our findings suggest the West Antarctic Ice Sheet may be close to a tipping point. But the Denman Glacier is so big -- at around 10 miles wide -- … Turney said this gap coincided with an extreme rise in sea level and suggested a period in which there was no ice accumulating in that valley. The general picture is that nonlocal MeanAnt produces relatively uniform melt rates within individual sectors, with maximum present-day melt rates below 25 m yr −1 (Fig. The process may expose ice cliffs so tall that they collapse under their own weight, inducing a domino effect that further depletes the ice shelf. The loss of the Thwaites glacier could trigger the broader collapse of the West Antarctic ice sheet. The models projected roughly 10.6 to 14.9 inches -- 27 to 38 centimeters -- of sea level rise during that same period without climate variability. These changes largely result from the geographic differences mentioned above, namely Antarctic sea ice’s distance from the pole (sea ice can melt ba… THIS POST IS A CRITICAL REVIEW OF A PHYS.ORG ARTICLE PUBLISHED IN OCTOBER 2020 SAYING THAT GLOBAL WARMING IS DRIVING ANTARCTIC ICE MELT AND GLOBAL SEA LEVEL RISE FASTER THAT LINK TO THE PHYS.ORG ARTICLE: THIS ASSEESSMENT IS CREDITED TO RESEARCH BY MATTHEW … While it is understood that continued warming may cause rapid ice loss, models that predict how Antarctica will respond to climate change have not included the potential impacts of internal climate variability, like yearly and decadal fluctuations in the climate, the team of scientists said. The authors say their findings could have “major implications” for the future given the ocean warming and ice melt currently occurring in Antarctica. Over the 1999-2019 period, more than 2.63 million square kilometers of the Antarctic ice sheet surface had experienced observable melting, which is nearly one-fifth of the total area, said the MOST 2020 annual report of remote When these winds blow over mountains, they remove snow and ice, allowing ancient ice to come to the surface. Fluctuations in the weather can have a significant impact on melting Antarctic ice, and models that do not include this factor can underestimate the global impact of sea level rise, according to Penn State scientists. That melt is equivalent to about 120,000 square miles of 1-meter thick ice. "That increase alone is comparable to the amount of sea level rise we have seen over the last few decades," said Forest, who has appointments in the departments of meteorology and atmospheric science and geosciences. The scientists found model simulations that did not include the effects of internal climate variability significantly delayed the retreat of the ice sheet by up to 20 years and underestimated future sea level rise. “What these results suggest, or show, is that when people talk about a 2C warmer world as a good thing, actually what it shows is we don’t want to get close to 2C,” he said. Compared to the Arctic, Antarctic sea ice shows less variability in summer, and more variability in winter. It flowed rapidly into the ocean,” he said.