Antarctic Glacier Mass Loss or Predicting Global Climate Risk?

# Antarctic # University of Houston: A researcher warned that the unprecedented large-scale loss of three Antarctic glaciers may indicate future global climate problems. A transnational cooperation is using advanced remote imaging system to record the Popper, Smith and Kohler glaciers with unprecedented clarity and integrity.

In a new study at the University of Houston, an advanced remote imaging system called synthetic aperture radar interferometry was used to record three glaciers in the Antarctic, and its clarity and integrity reached an unprecedented level. The new remote sensing data system not only reveals the cold secrets of the least explored continent on earth, but also warns of global climate risks-present and future.

An article published in the journal Nature Geoscience described in detail the unprecedented rapid retreat of the Popper Glacier, Smith Glacier and Kohler Glacier in Amundsen Bay in western Antarctica.

"Thanks to the new generation of radar satellites, in recent years, we have been able to witness the global glaciers retreating at an unprecedented rate. This is a warning signal that things have not stabilized, not at all. This may have serious consequences for the balance of the whole glacier system in this area, "said Peter Romilly Lo, a radar scientist who is an assistant professor of civil engineering at UH and the main author of the article.

In this ongoing international research on data collected by TanDEM-X and COSMO-SkyMed satellites, Milillo is cooperating with researchers and scientists from three national space agencies: University of California, Irvine, NASA, DLR and ASI.

The research team plans to extend its scientific knowledge gained from the relatively small and less studied Popper Glacier, Smith Glacier and Kohler Glacier to their huge and fragile neighbors in West Antarctica, glaciers in Thwaites and Pine Island, and the entire Antarctic glacier system.

"The problem here is that we found such a high retreat rate-so high that we actually saw that these three smaller glaciers can actually capture the basin from the nearby Svetz Glacier, which will cause Svetz to lose more mass," Milillo said. "In Antarctica, glaciers don't melt because of their interaction with the sun. They melt because they accelerate and inject more ice into the ocean. This is one of the main mechanisms of quality loss. "

At the southernmost tip of the earth, Antarctica is in darkness for most of the year. Its extreme weather means that researchers can only visit for a short time, which limits their research. Milillo pointed out that Antarctica is so far away that the nearest human beings are usually astronauts orbiting the earth on the International Space Station. )

"Radar is very suitable for these applications. The beauty of radar is that it can penetrate clouds. It can be observed in any weather condition. It is also an active sensor, so we don't have to rely on sunlight, "he said.

"In the past, we had to wait a few years to accumulate enough useful data. So we can only observe long-term trends. Now, we can check the glacier retreat on a monthly basis, and we can capture new details, which will help to improve the glacier model, and then improve our estimation of sea level rise, "Milillo said.

In these monthly surveys, the research team measures the altitude change every two weeks to evaluate the retreat of the glacier grounding line, and the boundary at the bottom of the glacier is the intersection of frozen soil and warm water. The grounding wire becomes particularly fragile, because warm water will form an ice shelf and begin to float, which is easy to be completely separated.

"If all the ice floes in Antarctica melt, the sea level will rise by an average of 58 meters (65,438+090 feet)," Milillo said. "If the signal we are observing is confirmed, the mass loss in Antarctica and Greenland will rise. As they rise, the sea level will also rise. "

"If all these glaciers melt, the sea level may rise rapidly. There are 267 million people in the world living on land less than 2 meters (6.6 feet) above sea level, which may lead to sudden migration. In addition, settlements may eventually lead to the sinking of large buildings in vulnerable areas, including Houston, "Milillo said. "This is why people should care about this problem. Even if it does not affect their lives, it will affect the lives of their children and grandchildren. "

At present, Milillo focuses on the near future, including NASA's plan to launch its NISAR satellite in 2023, which aims to provide more and more frequent data acquisition than the most advanced synthetic aperture radar. This satellite, also known as NASA -ISRO SAR, will measure the changes of ecosystems, dynamic surfaces and ice, and provide Milillo and other scientists with bolder and changeable pictures of the earth.