X. Moussas et al., THE 26 DAY VARIATION OF ENERGETIC PARTICLES AT HIGH HELIOGRAPHIC LATITUDES AND COROTATING VORTEX STRUCTURES, Astrophysical letters & communications, 34(1-6), 1996, pp. 213-218
It is proposed that large and small vortices (eddies) are produced, du
e to sheer instabilities, in the heliosphere near the heliospheric cur
rent sheet (HCS) and subsequently propagate away from it towards high
heliolatitudes under the influence of the Magnus force, The vortices c
ause large and small scale variations of the solar wind plasma and of
the interplanetary magnetic field producing Alfvenic fluctuations, acc
elerate and trap energetic particles and reduce the intensity of highe
r energy cosmic rays causing recurrent Forbush decreases, Most of the
large scale variations repeat with a quasiperiodicity of 26 days in Ul
ysses observations, i.e. with the synodical period of the spacecraft w
ith respect to the heliospheric current sheet where the vortices origi
nate. The vortices disintegrate continuously, producing smaller and sm
aller ones, in a cascade process and finally heat the solar wind plasm
a.