The wild winds of winter typically bring snow in the Northern Hemisphere. But sometimes, they carry dust. Earlier this month, winds brought clouds of dust from the Sahara Desert north towards the Mediterranean Sea and across Europe. When it mixed with various weather systems, dusty rain fell in parts of the United Kingdom, Spain, and France.
A new animation from NASA shows the highest concentration of dust and its movement throughout the region from March 1 to March 9. The graphic shows dust column mass density, which is a measure of the amount of dust contained in a column of air. It was made with a version of the Goddard Earth Observing System (GOES) model. GOES integrates satellite data with mathematical equations to show physical processes in the atmosphere as they happen.
Dust Outbreak Reaches Europe
The animation depicts the dust plumes from their origin point in northwestern Africa. The plumes are blown west across the Atlantic Ocean and then north toward the Mediterranean. When the plumes reached Western Europe, residents reported hazy skies in southern England and the Swiss and Italian Alps. A dust layer even reached the Matterhorn.
Some of the dust particles reached the ground as rain and coated the surface with a brown colored residue. A low-pressure system, named Storm Regina moved across Spain and Portugal, bringing blood rain to southern and eastern Spain, parts of France and the southern U.K.
Areas of “dusty cirrus” clouds developed higher in the atmosphere over the Mediterranean. According to MeteoSwiss, Switzerland’s Federal Office for Meteorology and Climatology, dust particles in this part of the atmosphere can help ice crystals condense. Studying these clouds to better understand their formation can offer insight into how they affect weather, climate, and even solar power generation.
In an analysis on Sarahan dust published this month in the journal Scientific Reports, scientists used NASA’s Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2), observations from Moderate Resolution Imaging Spectroradiometer (MODIS), and other satellite products. They analyzed the effect airborne Saharan dust has on solar power in Hungary, finding that a solar panel’s ability to directly convert sunlight into electricity dropped to 46 percent on high-dust days. By comparison, that number is 75 percent or more on low-dust days. According to the team, the greatest power losses happen because the dust enhances the presence and reflectance of cirrus clouds, reducing how much radiation that reaches solar panels.
More frequent and intense winter dust events have affected Europe in recent years, according to some new research. Scientists believe that drier-than-normal conditions in northwestern Africa and more frequent weather patterns driving winds north from the Sahara are potentially behind these increasingly dusty winters.
