The use of different solar activity indices like sunspot numbers, sunspot areas, flare index, magnetic fields, etc., allows us to investigate the time evolution of some specific features of the solar activity and the underlying dynamo mechanism. One of the problems when using these activity indices for some statistical analyses is the reliable determination of the maximum phases of different solar cycles which are generally characterized by a multi-peaked structure due to the presence of the so-called \emph {Gnevyshev gap}. The main aim of this work is to propose a general method, without the introduction of ad hoc heuristic parameters, to determine the duration of a given solar cycle maximum phase through a long-term solar activity index like the Monthly Smoothed Sunspot Number (SSN). The resulting extended solar maxima allows us to include the multi-peaked structure of solar cycles and further the proposed method allows us to predict the solar maximum duration of the current solar cycle 24.
Date added: Fri, 11 Oct 13