Nature Geoscience - How Dust From Melting Glaciers Affects Cloud Formations, Reflectivity
When glaciers recede, they leave barren landscapes behind. Dust from these surfaces can influence clouds high above, both how they form and how long they last, according to a recent study published in Nature Geoscience journal. Researchers on the Norwegian archipelago of Svalbard found wind-blown dust from receding glaciers is a catalyst for the formation of ice particle in clouds, impacting Arctic cloud development, lifetime, and reflectivity.
Glacier-sourced dust is made up of fine minerals and organic matter, pulverized over the millennia by the immense weight and slow scouring of glacier ice. The source of the organic matter is undetermined, yet the research team believes those particles are the key to the ice-nucleating ability of glacier dust.
In the low and middle latitudes, dust in the atmosphere is known to scatter light and cause air to condense and form clouds. Whether high-latitude dust emissions have a similar impact on Arctic clouds is not as well understood.
Glacier dust blows into the air over eastern Greenland on September 9, 2018. Runoff from several glaciers deposited sediment in a flood plain (Source: NASA).
Yutaka Tobo, an assistant professor at Japan’s National Institute of Polar Research, led a research team to see how the dust was affecting clouds. In particular, Tobo wondered whether they were triggering the formation of ice crystals, which can cause clouds to condense at low temperatures. Ice nucleating particles, Tobo’s team found, shorten cloud lifetime by prompting precipitation. Since icy clouds are less reflective than liquid-based clouds, the cloud’s capacity to reflect incoming light is also diminished, a key factor in the Earth’s ability to regulate its temperature.
“Few studies have focused on the possible contribution of dusts released from high-latitude sources to ice nucleation in Arctic mixed-phase clouds,” Tobo told GlacierHub. “If there are more ice nucleating particles around, the cloud properties and lifetime are expected to be dramatically altered.”
EDIT
http://glacierhub.org/2019/06/05/how-dust-from-receding-glaciers-is-affecting-the-climate/
