Dear colleagues,
we recently discovered a problem in one of the software tools used to retrieve the surface solar radiation from polar-orbiting (AVHRR) und geostationary (SEVIRI) satellite obervations. This software bug affected the operationally-available SIS and SID data from SEVIRI (starting 1 March 2012) and SIS data from AVHRR (starting 1 Jan 2009) and resulted in an underestimation of the surface radiation in the order of 5 to 15 W/m2, especially over land surfaces.
In all CM SAF SIS and SID data available after 1 May 2013 this bug has been fixed. For more information please the CM SAF Service Message 68.
We are sorry for any inconveniences this might have caused. Please let us know if you have further comments / questions.
Kind regards,
Jörg Trentmann
P.S. The geostationary CM SAF Surface Radiation Data Set is not affected by this bug.