Same as Fig. 1 but for the time interval of faculae-dominated TSI variability from 21-Dec.-2007 to 22-Mar.-2008. The purple dashed curve in panel a represents a sine wave function with a period of 26.4 d corresponding to the solar rotation period deduced with the GLS method. The orange curve in panel a is a sinusoidal function with a period of 27.8 d corresponding to the solar rotation period deduced with the GPS method.