Title: Modulation of High-Energy Particles and the Heliospheric Current Sheet Tilts throughout 1976-2014,
Abstract: Cosmic ray intensities (CRIs) recorded by sixteen neutron monitors have been
used to study its dependence on the tilt angles (TA) of the heliospheric
current sheet (HCS) during period 1976-2014, which covers three solar activity
cycles 21, 22 and 23. The median primary rigidity covers the range 16-33 GV.
Our results have indicated that the CRIs are directly sensitive to, and
organized by, the interplanetary magnetic field (IMF) and its neutral sheet
inclinations. The observed differences in the sensitivity of cosmic ray
intensity to changes in the neutral sheet tilt angles before and after the
reversal of interplanetary magnetic field polarity have been studied. Much
stronger intensity-tilt angle correlation was found when the solar magnetic
field in the North Polar Region was directed inward than it was outward. The
rigidity dependence of sensitivities of cosmic rays differs according to the
IMF polarity, for the periods 1981-1988 and 2001-2008 (qA < 0) it was R-1.00
and R-1.48 respectively, while for the 1991-1998 epoch (qA > 0) it was R-1.35.
Hysteresis loops between TA and CRIs have been examined during three solar
activity cycles 21, 22 and 23. A consider differences in time lags during qA >
0 and qA < 0 polarity states of the heliosphere have been observed. We also
found that the cosmic ray intensity decreases at much faster rate with increase
of tilt angle during qA < 0 than qA > 0, indicating stronger response to the
tilt angle changes during qA < 0. Our results are discussed in the light of 3D
modulation models including the gradient, curvature drifts and the tilt of the
heliospheric current sheet.