Modern understanding of the solar activity cycle as a global process from optical and radio observations

In this paper we present the arguments showing that the solar cycle must be studied as an essentially global process. Observations of polar faculae an d magnetic fields have shown that the solar activity at high latitude prese nts an important part of the solar cycle. Moreover there is connection betw een the amplitude and fluctuations of the polar activity and sunspot number s in the following solar cycle. The Nobeyama radioheliograph working since 1992 at wavelength of lambda=1.76 cm presents an unprecedented set of regul ar observations of the Sun. Comparison of Nobeyama radioheliograph observat ions with the data of the Kislovodsk Solar Station of the Pulkovo observato ry has shown the high effectiveness to study the solar activity and differe ntial rotation of the Sun at all latitudes using radio observations. (C) 20 00 Published by Elsevier Science Ltd. All rights reserved.