New research from the University of Wisconsin-Madison reveals that atmospheric rivers, concentrated flows of moisture in the sky, are a significant factor accelerating glacial melting over northern Greenland. The study, led by Kyle Mattingly, was published in Nature Communications.
Atmospheric rivers can stretch thousands of kilometers, carrying moisture from the tropics to other parts of the world, bringing rain to drought-stricken regions, but also causing dangerous flooding. However, in the case of Greenland, the northeast part of the ice sheet is greatly affected by atmospheric rivers.
Over the past 30 years, the Greenland ice sheet has experienced accelerated glacial melt. The ice sheet, which is 3,000 meters thick and contains enough water to raise sea levels by 7 meters, has regulated the earth’s climate and temperature for thousands of years. However, climate change is threatening its stability.
Warming conditions begin when atmospheric rivers form on the northwest side of Greenland and move eastward, creating Foehn winds that release heat into the atmosphere as moist air condenses and precipitates into rain or snow. This warmer and dryer air then flows over the ice sheet, creating warming conditions that are amplified over the northeast Greenland ice stream.
This area of fast-moving ice extends far into the interior and drains a significant portion of the ice sheet into the ocean. As a result of increased warm air conditions from atmospheric rivers, there are meltwater pools and rivers that absorb more sunlight than the nearby glacier.
Mattingly warns that with climate warming scenarios, the amount of moisture transported within atmospheric rivers is projected to increase, which may cause more significant melt impacts in northeast Greenland if atmospheric circulation patterns continue to favor atmospheric rivers tracking into northwest Greenland.