Publié le 4 juin 2019
Most of us probably wouldn’t think of describing snow in terms of its grain size. However, grain size is fundamental to the amount of sunlight that snow reflects back into space – its albedo. With both snow and albedo part of the climate system, scientists are applying a novel analytical theory to Copernicus Sentinel-3 data and shedding new light on Greenland’s changing albedo.
The amount of sunlight absorbed or reflected by Earth’s surface drives our climate and weather.
About one-third of the sunlight that hits Earth is reflected back into space and the other two-thirds is absorbed by the land, oceans and atmosphere. This ratio is governed by the reflectivity, or albedo, of the surface that the sunlight hits.
Surfaces with lighter colours reflect more sunlight than darker surfaces. An everyday example of this is the difference we feel on a hot sunny day when wearing black clothes compared to wearing white. Earth is affected in the same way.