Met-11 Convection RGB (header)

Meteosat-11 captures plume of Saharan dust

5 February 2021 09:00 UTC-7 February 11:00 UTC

Met-11 Convection RGB (header)
Met-11 Convection RGB (header)

On 5-6 February 2021, a massive amount of Saharan dust was advected across the Mediterranean Sea into central Europe, thanks to the favorable synoptic situation with a Low over Spain and a southerly jet stream over Morocco and the Mediterranean.

Last Updated

10 June 2022

Published on

08 February 2021

By Jochen Kerkmann (EUMETSAT), Mike Fromm (NRL), Miguel Angel Martinez (AEMET) and Ivan Smiljanic (CGI)

The dust plume can be clearly seen on the Terra MODIS True Colour RGB image from the morning of 6 February (Figure 1).

Terra MODIS True Color RGB
Figure 1: Terra MODIS True Colour RGB composite, 6 February 2021 (Credit: NASA). For the synoptic situation, see Met-11 Airmass RGB with isotachs 300 hPa (Credit: EUMeTrain)

High dust concentrations turned skies and snow to orange across southern and central parts of Europe (Spain, Andorra, France, Switzerland, Germany), creating dramatic scenery. The dust plume left deposits along the east coast of Spain, in particular Valencia, and orange snow on the Pyrenees and western Alps. While acknowledging this happens a few times a year (see the well documented case Extensive DIBS in the Deformation Zone from April 2020), meteorologists also noted this event was particularly intense.

Figure 2 shows the animation of the Dust RGB from the beginning of the dust outbreak in the border area between Morocco and Algeria, to its arrival over Switzerland and southern Germany. The animation is centred on the dust plume, i.e. it follows the mid-to-high level flow. This allows monitoring of the development of the dust plume from the first signs to its ingestion in the baroclinic cloud (cirrus) over central Europe.

Figure 2: Meteosat-11 Dust RGB, 5 February 09:00 UTC to 6 February 17:00 UTC (Credit: CIRA)

Figure 3 shows both, the dust plume over France, Italy and Switzerland at 12:00 UTC on 6 February (see Dust RGB, bright red colour, i.e. high level dust) and the DIBS (Dust‐Infused Baroclinic cyclone Storm clouds, also called 'dusty cirrus') cloud over France and southern Germany (see Convection RGB, strong yellow colour). The yellow colour indicates small ice particles, very characteristic for DIBS clouds. Another characteristic of DIBS clouds is their granular (pockmarked) structure, which is best seen in early morning HRV images.

RGB image comparison

Convection RGB compare1
compare2
 

Figure 3: Meteosat-11 Dust RGB (left) and Convection RGB (right), 6 February 2021, 12:00 UTC.

Aerosol Index comparison

Suomi NPP OMPS aerosol index compare1
compare2
 

Figure 7: Suomi NPP VIIRS I5 band (left, BTs below -50°C are shown in grey) and OMPS aerosol index (right). Credit: NASA.