Upper row (time series from 1880 to present):
Blue curve is the mean of GISS and HadCRUT4 (for the last year, only one time series (typically GISS) is used if the other time series (typically HadCRUT4) is not available yet); red curve is the mean of RSS and UAH. The mean temperature of the surface and satellite records overlap during 1979-2008; the first 30-year time period covered by both recordings.
Lower row (time series from 1979 to present):
As above, but for the individual time series from 1979 to present.