As the largest island on Earth, Greenland is largely within the Arctic Circle, with a cold climate and nearly 80 percent of its island covered in ice. But every year, in addition to the endless ice sheets, some special weather phenomena also occur in the region – in the island's ice-free coastal areas in autumn, in addition to the colorful changes of the Arctic tundra, there are also large sandstorms at this time of year!
On October 18, 2021, dust was in the air in many places along greenland's western coast, and images taken from NASA satellites showed at least 3-4 dust weather on the western coast of Greenland, with dust and dust streams blowing westward from the greenland coast, looking like spreading green smoke on satellite maps.
However, this kind of sandstorm is different from the familiar sandstorms in northern China, and the main component of this sandstorm is actually glacial silt or "stone powder" - that is, rock residues that are ground into powder by flowing glaciers. Whether it's glacial silt or rock powder, the material is very delicate and lightweight, and the wind can easily blow it into the air. According to NASA remote sensing scientist Santiago Gasso, dust storms like these are most common during the transition from summer to winter. For example, in September 2018, in a glacial valley off the east coast of Greenland, dry glacial silt was blown up by the wind and a massive sandstorm.
Dust storm in Greenland in September 2018
In summer, fast-flowing rivers carry meltwater away from the ice sheet and into the ocean. But in the fall, colder temperatures slow down the melting rate and the river recedes, revealing large areas of glacial silt. If snow has not yet begun to fall during this period, the silt begins to become dry, and once the wind blows a large amount of dust, forming an "Arctic dust storm".
On October 18, satellite monitoring of Greenland's glacial valleys was filled with suspended dust, indicating that the winds in the area were sending off massive sand dust.
Of course, sandstorms in this region are not only small in scale, but also have a different degree of impact from sandstorms in other parts of the earth, such as the sandstorms in the Sahara Desert can raise the sand and dust to a very high atmospheric level and blow the dust to thousands of kilometers away, while the dust storm dust impact in Greenland is concentrated at a relatively low altitude, generally no more than 1000-2000 meters in height. Still, winds through Greenland's glacial valleys create strong gusts of wind and carry dust hundreds of kilometers away in a day.
This dust may be carried far from the coast and may carry nutrients to areas where nutrients are not readily available, but that's not necessarily a good thing — a 2021 study showed that dust raised from Greenland can support the proliferation of glacial algae, mineral phosphorus, which can discolor the glacier surface. Just like soot or dust particles, algae growing on the surface of glaciers can also darken the ice, thereby reducing its albedo, absorbing more solar radiation and accelerating the melting of the Greenland ice sheet, thus deepening the global sea-level rise crisis.