In March 2022, several large storms brought clouds of Saharan dust to Europe
(ORDO NEWS) — In March 2022, several large storms brought clouds of Saharan dust to Europe. One also brought long-lasting high-altitude dust-soaked cirrus clouds that resulted in extensive cloud cover – from Iberia to the Arctic – for more than a week. It was an unusual type of storm that scientists only recently understood. Its hallmark is icy clouds riddled with dust called baroclinic dust-filled storms (DIBS).
In mid-March, an atmospheric river of Saharan dust was swept along by DIBS and ascended into the troposphere, reaching heights of up to 10 kilometers (6 miles).
The dust acted as nucleation ice particles, resulting in the formation of icy high-altitude cirrus clouds saturated with dust. They persisted for almost a week and covered a large part of Europe and Asia.
“In fact, two DIBS formed,” said Mike Fromm, meteorologist at the US Naval Research Laboratory. “The fact that the dust river fed two separate DIBSs makes this a notable phenomenon,” since more often than not a single storm is generated by the influx of dust.
The first storm began on March 15, 2022 over north central Europe and spread from Poland, the Czech Republic and Austria south to the eastern Mediterranean. This, too, was unusual, Fromm said, since “there is usually a direct link between the DIBS and the dry dust source, closer to the desert itself.”
On March 16, the second storm followed the classic pattern, swirling closer to the dust source in Africa. A large, widespread dust cloud continued to move north over Europe towards Scandinavia and the Arctic Ocean.
Then it moved eastward over northern Russia, after which it made an anticyclonic turn on March 20 and again descended into Eastern Europe and the Black Sea region.
In the above image taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA‘s Terra satellite on March 17, 2022, cloud tops appear pitted. “We still don’t know why this is happening,” Fromm said, “but it’s typical of DIBS.”
An analysis of mid-March storms by Colin Seftor, an atmospheric scientist at NASA’s Goddard Space Flight Center, showed that most of the dust circulated at the top of the cloud layer.
This means that there is enough dust on the tops of the clouds to give the normally white clouds a dusty tint, hence the name “blotches,” Fromm said. “In DIBS, dust and thundercloud are one.”
The map above shows the March 17 dust movement model based on the Goddard Earth Observing System version 5 (GEOS-5) model.
Fromm says the high dust clouds created by DIBS travel around the world and can sometimes be mistaken for volcanic ash, which can affect flight paths. They also have a local effect. Dust that is drawn into them tends to linger after the clouds evaporate, Fromm added. In addition, longer lasting cirrus clouds can affect temperature and precipitation forecasts.
At the end of March, another major dust storm began its journey northward, carrying Saharan dust over the Mediterranean and Europe.
While the latest storm seems just as big, it may not be as long, Sefthor said. “Two such large [storms] almost one after the other is somewhat unusual, but the weather conditions over northern Africa and Europe in the spring seem to be more favorable for dust storms to reach Europe than at other times of the year.”
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