Dust storms in Greenland
Nearly 80 percent of Greenland – the largest island on the planet – is covered in ice. But signs of autumn are still visible in the landscape, especially in the ice-free coastal areas of the island. In addition to the colorful changes in the Arctic tundra, major dust storms can rise at this time of year.
Dust was in the air on October 18, 2021, when Visible Infrared Imaging Radiometer Suite (VIIRS) is Finnish nuclear power plant satellite and Medium resolution imaging spectroradiometer (MODIS) at NASA Aqua the satellite acquired these images. At least four mists blew west from the coast of Greenland.
The “dust” in this picture is actually glacial sludge or “flour” – dusty remnants of rock that have been ground into powder by flowing glaciers. The material is so fine and light that winds can easily lift it into the air.
According to Santiago Gassó, a remote sensing researcher at NASA, large fillings like this are most common during the transition from summer to winter. In summer, fast-moving streams and rivers carry meltwater away from the glacier toward the sea. In the fall, cooler temperatures slow melting and river retreat, revealing large glacier sludge.
The detailed image above shows the airborne sludge generated from dry land near the Frederikshåb Isblink and Sermeq glaciers. It had not yet snowed in the area; when it does, it prevents the wind from raising more dust.
Even if the sludge is exposed on the surface, you still need strong winds to produce the fillings. Unlike the Sahara dust – where convection can raise dust high into the atmosphere – the dust in these pictures remained relatively low – Gassó estimates a maximum of 1-2 kilometers.
Yet the winds that flow through the valleys of the Greenland glacier can cause strong gusts and carry dust hundreds of kilometers a day. “This dust can travel very far from the coast, which can bring nutrients to areas where nutrients are not easy to obtain,” Gassó said.
Dust can also transport nutrients locally. A to study in 2021 showed that dust raised from Greenland can provide mineral phosphorus that supports the flowering of ice algae. Like soot or dust particles, algae can darken the ice, lowering its albedo and accelerating melting.
Lauren Dauphin’s NASA Earth Observatory imagery using NASA’s EOSDIS MODIS data LANCE and GIBS / Worldview and VIIRS data from NASA EOSDIS LANCE, GIBS / Worldviewand Finland’s national polar partnership. The story of Kathryn Hansen.