قالب وردپرس درنا توس
Home / Science / Almost a quarter of West Antarctic ice is now unstable – ScienceDaily

Almost a quarter of West Antarctic ice is now unstable – ScienceDaily



The British Center for Polar Observation and Modeling (CPOM) has been tracking changes in snow and ice cover across the continent by combining the European Space Agency's 25-year satellite height measurement with a regional climate model.

A team of researchers, led by Professor Andy Shepherd of the University of Leeds, found that Antarctic ice has thinned up to 122 meters in some places, with the fastest changes in West Antarctica the melting of the oceans has led to an imbalance of glaciers.

means that the affected glaciers are unstable, as they lose more mass by melting and calving icebergs than by snowfall.

The team found that the pattern of glacier thinning was not static. Since 1992, thinning has spread to 24% of the West Antarctic and most of its largest ice flows ̵

1; the Pine Island and Thwaites Glaciers – which now lose five times faster than at the beginning of the survey.

The study published today in Geophysical Research Letters has used over 800 million measurements of the height of the Antarctic ice sheet recorded by the satellite altimeter ERS-1, ERS-2, Envisat and CryoSat-2 In 1992 and 2017 and simulations of snowfall in the same period according to the regional climate model of RACMO.

Together, these measurements allow changes in ice sheet height to weather-related changes such as less snowfall and subdivide B. by longer-term climate changes, where sea temperatures rise and the ice eats.

Senior author and CPOM director Professor Andy Shepherd stated, "In parts of the Antarctic, the ice cover has greatly diluted amounts, and so we set out to show how much was caused by climate change and how much by weather.

The team compared the measured change in surface elevation to the simulated changes in snowfall and where the larger the discrepancy was, the greater the cause of the imbalance of the glaciers.

They found that snowfall fluctuations tend to cause small elevation changes over large areas over several years. The strongest changes in ice thickness, however, are signals of decades of imbalance in the glaciers.

Professor Shepherd added, "Knowing how much snow has fallen has really helped us to understand the underlying change in the glacier ice in the satellite image." We can now clearly see that a wave of thinning is fast on some the most vulnerable Antarctic glacier has spread and whose losses have caused the sea level around the planet to rise.

Overall, ice losses from the eastern and western Antarctic 4.6 mm contributed to the rise in global sea level since 1992. "

Dr , Marcus Engdahl of the European Space Agency, co-author of the study, added: "This is an important demonstration of how satellite missions can help us to understand the state of our planet Polar regions are hostile environments and extremely difficult to access from the ground the view from space is an important tool to track the effects of climate change. "

Story Source:

Materials Provided by University of Leeds . Note: Content can be edited by style and length.


Source link