SILSO SSN hemispherical time series extension using UCCLE station at ROB. On the top panel we shown the monthly SSN time series (using black color for UCCLE and red for SILSO), in the middle panel the 13-month smoothed equivalent SSN time series and in the bottom panel the merging of the time series around 1992 using cyan color for UCCLE, red for SILSO and black color for the merged time series.