Synoptic limb charts obtained for 171 Å (top panel), 304 Å (middle panel) and 17 GHz (bottom panel). Running means of 3 days were applied in the synoptic charts of each wavelength. The minimum values of the color scales for the I_R are 0.5 at the EUV (171 and 304 Å) lines and 0.70 at radio (17 GHz), while the maximum values are 5.50, 3.30 and1.40 at 171 Å, 304 Å and 17 GHz, respectively. The dotted lines delimit the south (60° and 120°) and north (240° and 300°) poles.