====== Land ======

===== Meteosat-8 images =====

8 March 2006 12:00 UTC, dust outbreak over the Sahara.

The desert surface is characterized by very low emissivity at IR8.7μm, we can see it appear darker on the image:

{{aerosols:200603081200_spp_T3.png|8.7μm brightness temperature}}

If we make the difference between 8.7μm and 10.8μm we are able to separate the clear-sky regions from the regions with aerosols:

{{aerosols:200603081200_T3_T5.png|difference image 8.7μm -- 10.8μm}}

In order to make a reference image with the surface contribution we estimate the surface emissivity from the clear-sky observations:

{{aerosols:200603081200_emissivity_108.png|10.8μm land surface emissivity}}