Are you converting the data into an imprecise data type (such as 8bit int)?
Depending on the scaling you apply it could be that the values in that
region (~350K) are too high for the data type and so 'roll over' into a
very low value. This happens to us occasionally when calculating
reflectance in the twilight region.

/random guess

Cheers,
Simon
=====================================

Simon,

Likely the guys are using the images from the MSG Data Manager software. The thermal scaling applied to the images avoids wrap-around artefacts such as you mention.

Cheers,
David
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