The accurate characterization of near-surface winds is critical to understanding past and modern climate.
Dust lifted by these winds has the potential to modify surface and atmospheric conditions, according to a University of Wyoming researcher who was part of a study on the subject.
“This study demonstrates an intricate coupling between land surface changes and wind speeds. Specifically, the wind acts to erode sandy deserts,” says Zachary Lebo, a UW assistant professor of atmospheric science. “As a result, the surface transitions from a sandy surface to one composed of large rocks that tend to be darker and, thus, absorb more sunlight or decrease the albedo on the surface. This causes the ground to warm.”
Surface albedo is the fraction of sunlight reflected off a surface, Lebo says. For example, snow has a really high albedo because it reflects a lot of light from the sun. On the other hand, asphalt has a very low albedo because it reflects very little light and, thus, absorbs a lot of sunlight, which causes it to be quite warm in many instances.
“Why is this important? Temperature gradients can ultimately impact wind speeds,” Lebo continues. “So, changing the temperature over the desert changes the temperature gradient, which changes the wind speeds -- in this case causing them to increase.”
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Image via University of Wyoming
