A recent study from the University of Wisconsin-Madison has found that atmospheric rivers are a crucial element in the complex conditions that are leading to the acceleration of glacial melting in northern Greenland. Atmospheric rivers are long, concentrated flows of moisture in the sky that can stretch thousands of kilometers. They are an essential part of the global weather cycle, replenishing parts of the world that are in drought. However, they can also lead to dangerous flooding.
Impact on Greenland’s Ice Sheet
The Greenland ice sheet is covered by a 3,000-meter thick ice sheet that holds enough water to raise the sea levels by 7 meters. The ice sheet has played a critical role in regulating Earth’s temperature and climate for millennia. However, due to climate change, the stability of the ice sheet is under threat. The study led by Kyle Mattingly at the University of Wisconsin-Madison has shown that atmospheric rivers are a significant factor in the acceleration of glacial melt over the last 30 years.
The warming conditions begin with atmospheric rivers that form on the northwest side of Greenland and move eastward, creating Foehn winds. These winds occur when moist air meets an elevation change like a mountain or the steep Greenland coastline. As that wet air climbs higher, it condenses and can precipitate in the form of rain or snow, releasing heat into the atmosphere. Now warmer and dryer, the air continues to flow over the ice sheet and back down the northeast side of Greenland.
As per Mattingly, these warming conditions are amplified over the northeast Greenland ice stream, an area of fast-moving ice that extends far into the interior and drains a significant chunk of the ice sheet into the ocean. The increase of warm air conditions from atmospheric rivers results in meltwater pools and rivers that absorb more sunlight than the nearby glacier. Mattingly warns that if atmospheric circulation patterns continue to favor atmospheric rivers tracking into northwest Greenland, the amount of moisture transported within atmospheric rivers may increase in climate warming scenarios, leading to greater melt impacts in northeast Greenland.
In conclusion, atmospheric rivers are an essential part of the global weather cycle, but their significant impact on the acceleration of glacial melting in northern Greenland is a cause for concern. The study highlights the need to monitor and understand the complex conditions that are leading to the melting of the ice sheet, which can have significant consequences for sea levels and the climate.