Satellite obs. of "solar constant" [World Radiation Center (Davos)]

[The figure presented here were taken from the WWW site of
Physical-Meteorological Observatory Davos, World Radiation Center
http://www.pmodwrc.ch/solarconstant.html ]
Unit: W / m^2.  Y axis: upper panel 1362-1374; lower panel 1363-1368
Bottom axis shows year (1978-2003), top axis shows days since year 1980