[2] If we define "heliosphere" as a space surrounding the Sun with the plasma and magnetic field originated on the Sun and controlled by it, this definition implies that in different heliospheric characteristics one can see variations inherent in the surface layers of the Sun. In particular, the main solar variation in the sunspot number, magnetic flux, and so on, known as the 11-year cycle or, simply, solar cycle (SC), is reflected in many heliospheric characteristics. We are interested in isolating the extreme phases (minima and maxima) of the solar cycle in the galactic cosmic ray (GCR) intensity modulation in order to consider both the main long-term variations of the GCR and some specific for these phase GCR effects.
[3] Of course, both the solar cycle and the space, time, and energy distribution of the GCR intensity during solar minima and maxima are the subjects of a great number of papers (see McDonald [1998] and Potgieter et al. [2001] for the reviews of the observations and modeling, respectively). However, when one discusses the situation in the solar maxima and minima, usually very short periods (two to three solar rotations long) are considered, when the GCR intensity attains its extreme values. Even in cases when the attention is concentrated on the intensity behavior around these extreme points (as in, e.g., our papers devoted to the study either of the GCR intensity dependence on the tilt of the heliospheric current sheet in solar minima [Krainev and Webber, 1993b] or of the double-peak structure of the intensity modulation in solar maxima [Krainev et al., 1999]) the boundaries of the periods considered are not substantiated by some physical reasons.
[4] In section 2, after comparing the solar cycle in the GCR intensity and some solar and heliospheric indices we discuss the reasons and merits of isolating the extreme phases in the GCR intensity modulation. Sections 3 and 4 will be devoted (1) to the discussion of some classification which we choose as an initial approximation for our purposes and (2) to outlining and briefly discussing some questions concerning the main solar cycle phases for the GCR intensity modulation. Then we very briefly discuss a topic although not directly relevant to the main subject of the paper but very important for the manifestation of the solar cycle in the heliosphere; namely, we review the general views about the heliospheric surroundings and what would occur if the Sun were slightly off its place in the Galaxy.
Citation: 2004), Main phases of the solar cycle in the galactic cosmic ray intensity, Int. J. Geomagn. Aeron., 5, GI2004, doi:10.1029/2004GI000070.
Copyright 2004 by the American Geophysical Union (