A massive plume of dust lifted from the Sahara Desert swept across parts of Europe in early March, leading to unusual “dirty rain” events in Spain, France and the United Kingdom.
Strong winter winds carried clouds of fine desert dust northward across the Mediterranean between March 1 and March 9, spreading hazy skies across large parts of Western Europe.
When the airborne particles mixed with rain-bearing weather systems, the result was muddy or “blood rain” that left a brownish residue on cars, buildings and streets.
WATCH HOW SAHARA DUST IS MOVING OVER EUROPE
Scientists tracked the event using the Goddard Earth Observing System model, which combines satellite observations with atmospheric physics to simulate dust movement.
The data showed large plumes of Saharan dust originating in northwestern Africa and spreading both westward across the Atlantic Ocean and north toward the Mediterranean and Europe.
As the dust travelled across the continent, people reported hazy skies stretching from southern England to the Alps. In mountainous areas of Switzerland and Italy, a visible dust layer settled over snow-covered landscapes, even reaching iconic peaks such as the Matterhorn.
The dusty rainfall was linked to a low-pressure system named Storm Regina by Portugal’s weather service. The storm moved across the Iberian Peninsula, pulling moisture into the atmosphere and causing dust particles suspended in the air to fall to the ground with rain.
The phenomenon coloured rainwater reddish-brown in southern and eastern Spain and parts of France, creating what is popularly known as “blood rain”.
Scientists say Saharan dust regularly travels long distances across the Atlantic and Europe, but the scale of some recent winter events has drawn increasing attention.
High above the Mediterranean, dust particles also helped form unusual “dusty cirrus” clouds. According to MeteoSwiss, dust can act as condensation nuclei in the upper atmosphere, allowing ice crystals to form and creating thin cirrus clouds that influence weather and climate.
Researchers are studying how such dust events affect solar energy production as well. Using data from MODIS and MERRA-2, scientists recently found that heavy Saharan dust episodes significantly reduced solar power generation in parts of Europe.
The study showed that photovoltaic efficiency dropped to about 46 percent on high-dust days compared with more than 75 percent during clearer conditions. Scientists say the drop occurs because dust enhances reflective cirrus clouds and reduces sunlight reaching solar panels.
Some researchers believe Europe may see more frequent winter dust outbreaks as changing climate conditions, including drier conditions in northwestern Africa and shifting wind patterns, make it easier for Saharan dust to travel north.
