Meteosat 8 Airmass RGB

09 August 2005/00 UTC

The major feature in the airmass image throughout this sequence is the advection and development of the areas having a bright red colour. The red colour is associated with the brightness temperature difference of the two water vapour channels 6.2 and 7.3. It indicates areas of lowered tropopause and high upper tropospheric PV values.

In principle green and blue colours in the airmass image stand for different airmasses (green represents warm midlatitude or tropical airmass, blue polar airmass). However, because of the limb effect in the northeasternmost corner of the image, the colours are distorted and hence the warm airmass in Russia has a strong magenta colour instead of a greenish colour.

Note. You can always click on the to bring up the RGB-key.