High level cloud spreading from Mt. Etna

Large dust fan over northwest Africa

09 March 2007 12:00 UTC

High level cloud spreading from Mt. Etna
High level cloud spreading from Mt. Etna

The imagery shows a cyclone over Tunisia and the related cold air outbreak from Western Europe to Northwest Africa, which caused a major dust storm.

Last Updated

18 August 2021

Published on

09 March 2007

By Jochen Kerkmann (EUMETSAT)

Similar to the famous case of 3 March 2004, as it moved southward, the cold air fanned out across the Sahara, highly diverging over subtropic regions giving the dust front the form of a Spanish fan.

It should also be noted that the colour of the leading dust front varies throughout the day, from dark magenta/blue (night) to bright magenta (midday). This is typical for thin dust clouds at low elevations (1–2km) over desert surfaces when the temperature contrast between the dust cloud and the underlying surface changes a lot from day to night. Thin dust clouds at high elevations do not show such a strong colour variation but appear with a more stable redd colour.

High level cloud spreading from Mt. Etna
Figure 1: Met-8 RGB Composite IR12.0–IR10.8, IR10.8–IR8.7, IR10.8, 9 March 2007, 12:00 UTC
Animation (02:00–08:45 UTC)

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