Southwestern Europe is currently experiencing an exceptional Saharan dust episode, which has been turning skies across the region orange. The Copernicus Atmosphere Monitoring Service (CAMS*) predicted that this large-scale transport of Saharan dust would travel northwards, over many parts of western and central Europe, with dust concentrations higher up in the atmosphere reaching further north, bringing hazy skies as far as Britain and Denmark. The concentrations are the highest on record based on measurements from several stations in Spain, according to El País and the Barcelona Dust Center.

Earlier in the week the CAMS forecast showed very high concentrations of coarse particulate matter (PM10) over north Africa and the Iberian Peninsula. The CAMS regional ensemble analysis over Spain shows concentrations reaching up to 650 µg/m3, but some of the individual regional models in the ensemble give values near 2000 µg/m3.

This has now been confirmed by analysis in Spain’s El País newspaper and the Barcelona Dust Center with data from the Spanish Ministry for the Ecological Transition and the European Environment Agency EEA.

It reveals historically high PM10 concentrations in 107 of the country’s 471 measurement stations. Some of them exceeded average concentrations of 1700 µg/m3, with El Eijdo station in Almeria reaching 1779 µg/m3. Some stations stopped recording after reaching 1000 µg/m3. El País notes that the average daily exposure considered safe for health by WHO is under 45 µg/m3.

Scientists at the Barcelona Supercomputing Center confirm that the observations in the EEA NRT repository were extreme. “In Spain in particular, the regions more impacted were the southeast and the central Iberian Peninsula, as is also shown in the CAMS and WMO SDS-WAS multimodel results. The region of Andalucía registered hourly maximum PM10 values between 194 and 3782.16ug/m3 for 15 March 2022. The hourly maximum PM10 of 3782.16ug/m3 was registered in El Ejido in the province of Almería,” explained researcher Sara Basart. These numbers are comparable to PM10 concentrations in Indonesia during the 2015 fires, and Siberia during the 2021 fires, according to preliminary estimates by CAMS.
By the morning of Tuesday, 15 March, the plume of Saharan dust covered most of Spain and south-eastern France and CAMS predicted the plume would continue to travel across Western Europe and the Mediterranean during the week, covering large areas of France, Switzerland, Austria, the Netherlands, Germany or yet Britain.

As for Friday 18 March, CAMS forecasts show the remnants of the Saharan dust cloud reaching as far as Finland, and new dust spells over the Mediterranean, consistent with the Barcelona Dust Center prediction. Concentrations are expected to decrease during the weekend.

These Saharan dust episodes are common in the Mediterranean and in the Atlantic, where they can play a role in the ecosystem of the ocean and even of the Amazon rainforest. Last month we reported on the year’s first Saharan dust transport events, which travelled across the Canary Islands and northwards as far as Iceland. A similar transport event was observed recently, with dust traveling across Cape Verde on 3 March on its way over the Atlantic to the Caribbean and South America. This long-range transport is still ongoing and the accuracy of CAMS forecasts is being confirmed by Aeronet readings at different sites in the Atlantic and Caribbean. READ FURTHER FROM THE SOURCE ABOVE