Snow covered land
Snow appears cyan in the HRV Fog RGB images.
The image left and the two images below show several snow covered European Mountains. The snow on the high mountains shows usually brighter cyan colour, than on the mainland or on the hills, as the snow cover is less disrupted by vegetation. One can often see the typical structure of the valleys, ridges.
Meteosat, SEVIRI HRV Fog RGB for 13 March 2014, 11:40 UTC
Meteosat, SEVIRI HRV Fog RGB for 7 March 2014, 08:40 UTC
The following image shows snow covered mainlands, low hills (with clouds in some areas). In the less bright cyan colour one can see patches, spots, lines. Patches might be due to forest with shadows and branches not covered by snow. Lines might be due to rivers, spots (small patches) due to settlements.
Meteosat, SEVIRI HRV Fog RGB for 8 January 2009, 09:55 UTC
Explanation of the colours of snow in the NRV fog RGB (see the recipe):
• Snow has low reflectivity in the 1.6 micrometer channel. The signal in the red colour beam will be low (less than medium) even after the linear stretching in the 0-70 % reflectivity interval.
• Snow has high reflectivity in the HRV channel, resulting strong signals in the green and blue colour beams.
As a consequence snow appears cyan in the HRV Fog RGB images: high and equal signals in the green and blue colour beams and much weaker signal in the red colour beam.