Scientists suggested the collapse of the Larsen A and B ice shelves was due to the arrival of atmospheric rivers. The study was published in the journal Communications Earth and Environment. Scientists described how they tracked the movement of atmospheric rivers during the time period when the ice shelves collapsed and what their work reveals about likely scenarios unfolding in Antarctica as global warming continues.
Ice shelves form when ice from glaciers meet the sea and they float on top of the ocean. Previous research has suggested that ice shelves have begun to breakup as global warming continues. These breakups do not contribute to a rise in ocean levels. Their loss does allow the glaciers that spawned them to flow unimpeded into the sea. It does raise sea levels. Prior research has also shown that one of the major reasons for ice shelf break up is the flow of warmer water beneath them. Scientists have found that atmospheric rivers are also very likely a contributing factor.
Atmospheric rivers are currents of air that have different properties than the air around them. They are warmer and thus carry more moisture. Scientists used a variety of tools, to learn more about the possible impact of atmospheric rivers when they flow into the Antarctic region. Scientists used a variety of tools; it includes a computer algorithm developed specifically to detect atmospheric rivers and climate models and imagery captured by satellites. By identifying and following the paths of atmospheric rivers as they arrived at Antarctica. They found that one arrived in 1995 just before the collapse of Larsen A. Another arrived in 2002 just before the collapse of Larsen B.
Further study of the two events showed that the warm moist air from the atmospheric rivers led to melting of the surface ice. It seeped into cracks and refroze. This led both of the shelves to be exposed to ocean swells that tore them apart. Scientists found that atmospheric rivers played a role in triggering 13 of 21 iceberg calving events between 2000 and 2020.