|Manu||Date: Tuesday, 02-November-2021, 8:25 PM | Message # 1|
|Satellite monitoring of Greenland ice melting highlights global flood risk|
by University College London
Global warming has caused extreme ice melting events in Greenland to become more frequent and intense over the past 40 years, raising sea levels and flood risk worldwide, finds new research involving UCL academics.
Over the past decade alone, 3.5 trillion tons of ice has melted from Greenland's surface and flowed into the ocean—enough to cover the UK with around 15m of meltwater, or all of New York City with around 4500m.
Published today in Nature Communications, the new study is the first to use satellite data to detect this phenomenon—known as ice sheet runoff—from space.
Funded by the European Space Agency (ESA) as part of its project "Polar+ Surface Mass Balance Feasibility," the study used measurements from the ESA's CryoSat-2 satellite mission, using estimates of surface elevation change over time.
One of the very few satellites orbiting with 2 degrees of the planet's poles, CryoSat-2 has provided scientists with a long history of data no other spacecraft could reach since its launch over 11 years ago, transforming scientist's capacity to study the polar regions. It remains key to research and knowledge critical to decision-making on the planet's health.
Study co-author Lin Gilbert (UCL Mullard Space Science Laboratory) said: "Observations show that extreme melt events in Greenland have become more frequent and more intense—as well as more erratic—which is a global problem. Monitoring from space enables us to cover the whole of Greenland (and nearly all Antarctica) repeatedly, which can't be done by teams on the ground. This is the first-time run-off has ever been measured directly from space—allowing us to remotely observe hard-to-explore regions of the ice sheets and use these observations to form an enhanced understanding of why this is happening and what we can do about it in future."
The international team of researchers found that over the past four decades Greenland's meltwater runoff has risen by 21%—and has become 60% more erratic from one summer to the next.
The findings revel that between 2011 and 2020 increased meltwater runoff from Greenland raised the global sea level by one centimeter—heightening the risk of flooding worldwide and disrupting marine ecosystems in the Arctic Ocean. Raising sea levels can also alter patterns of ocean and atmospheric circulation that affect weather conditions across the globe.
Read more/full article/source - https://phys.org/news....al.html