Millimeter-radio, SOHO/EIT 171 angstrom features and the polar faculae in the polar zones of the Sun

In this work we study different manifestations of activity in the polar zon es of the Sun in order to gain understanding on the phenomenon of enhanced radio temperature regions (ETR) at high solar latitudes. We have obtained s imultaneous radio and optical data during 9 days in 1997. The radio data fr om the Metsahovi radio telescope, Finland, consisted of 37 GHz and 87 GHz s olar maps. White light observations at the Kislovodsk solar mountain statio n in Russia were used to measure the coordinates of polar faculac groups an ti diffuse bright structures. We also compared our data with the 171 Angstr om EUV SOHO/EIT images for the same time periods. We find the ETRs in gener al coincide with the relatively dark areas seen in the SOHO/EIT images. Bri ght structures in the SOHO/EIT maps are, in general, encircled by the polar facular groups and diffuse bright structures visible in white light. Some of the EUV bright structures appear to be bases of solar plumes. Connection s between ETRs and polar faculae are complicated; sometimes polar faculae g roups and diffuse bright structures: are situated around the ETR maxima or at their borders, sometimes we see the polar faculae groups distributed ove r the whole ETR area. Some faint ETRs appear to have no associated polar fa culae. However, in general there is a correlation between the ETRs, the pol ar faculae groups, and the bright structures (bases of the plumes and some other features), indicating that they are different manifestations of the s ame underlying activity. It is possible that magnetic loops in the active a reas, traced by the polar faculae, are responsible for the observed radio e nhancements.