New study highlights warming and melting complexity in Antarctica

In a study published on Nature Climate changeToday, scientists at the SOS website are relying on recent discoveries to highlight the multifaceted dynamics of superficial melting in Antarctica. The authors of the study come from the Lamont-Doherty Earth Observatory of Columbia University, the Cooperative Research Institute of Environmental Sciences of the United States. University of Colorado at Boulder and Rowan University.

Antarctica is often considered a cold, high and dry place, and certainly the largest ice cap on the Earth, which currently blocks about 58 meters of rising sea level. Recent reports indicate that in the warmer future, more of the surface of the Antarctic Ice Sheet will melt. Whether this new water accumulates in the lakes, moves in the rivers or is absorbed into the snow near the surface, in the manner of a sponge, has enormous consequences on the water. sea ​​level rise around the world.

Today, Antarctica loses most of its ice mass by melting away from the ocean and separating itself from the breaking of icebergs. But recent research indicates more and more that this is not always the case. As global temperatures continue to rise, the Antarctic could gradually face a loss of ice from top to bottom, also due to the warming of the atmosphere. In fact, recent modeling work has shown that this could be a warmer atmosphere that would feed Antarctic's major contributions to sea-level rise during this century. This modeling work has been complemented by observations over the past several decades in the Antarctic Peninsula region, where several pack ice broke up due to the warming of the air, which caused an increased surface melt. This melting formed large meltwater lakes that caused the fracture and fragmentation of the pack ice. Once this dissolution occurs, the ice of the inner Antarctic accelerates in the ocean.

However, in our ever-evolving understanding of Antarctic melting water production, the authors also demonstrate that a warming of the atmosphere is only a consideration; Winds and local scale reactions can be even more important for melted melt. For example, this warmer atmosphere can lead to more snowfall, which, perhaps counter-intuitively, could also prevent melting, while creating more of a sponge-like layer of hazelnut to absorb water. of cast iron.

Understanding what happens to meltwater after its formation is a crucial problem that needs to be solved. Science has acquired a certain idea of ​​Greenland, where the melting of surfaces is much more important nowadays. For example, in Greenland, we know that meltwater can seep into the snow and settle in the subsoil, forming vast aquifers. If such features begin to form on Antarctic ice shelves, they could threaten the future stability of ice shelves. However, the Antarctic ice shelves are not the only thing that should worry us in the future. If the surface of Antarctic ice melts sufficiently on the surface, some of this water could reach the base of the ice cap and affect the flow of ice in the ocean, as it is already the case in a large part of the ice sheet of Greenland.

In the end, the authors argue that solving the problem of the Antarctic's response to climate change is an increasingly complex task. It has created new questions and an urgent need for a concerted, multidisciplinary and international effort. They write that observations are needed today from ground and space, and it is imperative that ice cap patterns and climate be representative of the various processes affecting melting and hydrology in Antarctic. Because of the potential of Antarctica to dramatically alter the sea level, these urgent concerns require increased scientific attention.

Explore further:
Antarctic melt slows atmospheric warming and accelerates sea level rise

More information:
Robin E. Bell et al. Antarctic surface hydrology and impacts on the sea ice mass balance, Nature Climate change (2018). DOI: 10.1038 / s41558-018-0326-3