A deformation zone over parts of Europe, in January 2017, appeared on Meteosat Airmass imagery as a rainbow pattern.
By Djordje Gencic (RHMSS) and Ivan Smiljanic (SCISYS)
On 17 January a very interesting rainbow-looking feature stretched from the area of the Baltics, over Germany, France and all along to the Western Mediterranean Sea. This was how a deformation zone appeared on the Meteosat-10 Airmass RGB (Figure 1).
A deformation zone occurs when, thanks to the special positioning of pressure systems, there is a quasi-stationary spreading movement of air, so it eventually appears as a long filament structure at the ends of which are low pressure systems.
The rainbow-like pattern was caused by the properties of air and the way these properties are represented in the Airmass RGB. From the northern and western side of this zone, there was a polar maritime airmass, which usually appears as blue. At the same time on the other side of the zone, there was an intrusion of dry stratospheric air from the far northeast of Europe, which usually appears as strong red (Figure 2).
Therefore, in the aforementioned area of the deformation zone there was a very strong transition from blue to red over a relatively small distance, resulting in the colourful, rainbow-like view.