Meteosat-8 24h Microphysics RGB

Large dust clouds over northern Europe

30 September 2020 09:00 UTC and 3 October 00:00 UTC

Meteosat-8 24h Microphysics RGB
Meteosat-8 24h Microphysics RGB

In the Autumn of 2020, the largest European-made dust clouds ever seen in Meteosat imagery were captured on two RGB products.

Last Updated

28 January 2021

Published on

27 January 2021

By Jochen Kerkmann (EUMETSAT), Ivan Smiljanic (CGI), HansPeter Roesli (Switzerland), Izolda Marcinoniene (LHMT)

European forecasters were puzzled about unusual large dust clouds over the Baltic area in Autumn 2020. In the morning of 1 October 2020, weather forecasters from northern Europe were discussing an unusual pink cloud over the Baltic countries, which appeared in the Meteosat-11 Dust RGB and 24h-Microphysics RGB (Figure 1).

Meteosat-11 24h microphysics RGB
Figure 1: Meteosat-11 24h-Microphysics RGB, 1 October 09:00 UTC. First dust outbreak.

Izolda Marcinoniene from the Lithuanian Hydrometerological Service contacted the EUMETSAT training team asking whether this cloud could originate from Ukrainian fires (i.e. smoke clouds). This hypothesis was quickly discarded as smoke is usually transparent in infrared channels (unless it is a very thick, high-level smoke cloud).

After checking various RGB products of 30 September and 1 October, using EUMeTrain ePort Pro, it was concluded that it was a dust cloud (not smoke or ash), but where could this large amount of dust have come from? The answer was found by looking at the backward trajectories of the dust cloud. The source of the dust was identified to be in southern (European) Russia, where there had been two major dust outbreaks in the semi-arid area north of the Caucasus mountains, one on 30 September and one on 1 October (Figures 2 and 3).

Meteosat-11 Dust RGB
Figure 2: Meteosat-11 Dust RGB, 30 September 09:00 UTC.
Meteosat-8 24h Microphysics RGB
Figure 3: Meteosat-8 24h-Microphysics RGB, 1 October 12:00 UTC.

These outbreaks led to two consecutive dust clouds crossing the Baltic area and Scandinavia, which were the largest European-made dust clouds ever seen in Meteosat imagery. The dust cloud that crossed the Baltic countries on 1 October is the larger, more 'beautiful' one seen in the half-hourly animation from 09:00 to 23:30 UTC (Figure 4).

Figure 4: Meteosat-8 24h-Microphysics RGB, 1 October 09:00-23:30 UTC (half-hourly images).

This impressive dust cloud (magenta colour) crossed the Baltic countries, Finland, the Baltic Sea and Sweden. On the subsequent days, the dust continued its way westward, crossing Sweden and Norway, entering the North Atlantic area.

On 3 October at 00:00 UTC two dust clouds could easily be identified over the North Atlantic; the additional dust cloud, related to the second dust oubreak over southern Russia, stretched from Sweden across the Baltic Sea to Finland (Figure 5).

Meteosat-11 24h microphysics RGB
Figure 5: Meteosat-11 24h-Microphysics RGB, 3 October 00:00 UTC.