'Japan Society of Plasma Science and Nuclear Fusion Research'
Abstract
he relation between the dynamics of the heliosphere,
its shape and geometry, so
lar activity and cosmic ray
variations is addressed. The global features of the helio
sphere influence what happens
inside its boundaries on a
variety of time-scales. Galactic and anomalous cosmic rays are the messengers that convey vital information on
global heliospheric changes in the manner that they respond to th
ese changes. By observing neutral and charged
particles, including cosmic rays, over a wide range of energies on various spacecraft and at Earth, a better
understanding is gained about heliospheric phenomena including space weather and space climate. Causes of
cosmic ray modulation and variability in the heliosphere are reviewed, with emphasis on the 11-year and 22-year
solar activity cycles, step-modul
ation, charge-sign dependent modulation and
particle drifts. Advances in this field
will be highlighted such as the ef
fects of the solar wind terminati
on shock and the heliosheath on cosmic ray
variability, also related to important recent observations in the heliosheath by the two Voyager spacecraf