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Cosmic Rays in the Inner Heliosphere: Insights from Observations, Theory and Models
Potgieter, M. S.
The global modulation of galactic cosmic rays in the inner heliosphere is determined by four major mechanisms: convection, diffusion, particle drifts (gradient, curvature and current sheet drifts), and adiabatic energy losses. When these processes combine to produce modulation, the complexity increases significantly especially when one wants to de…
Solar Drivers of 11-yr and Long-Term Cosmic Ray Modulation
Richardson, I. G.; Ling, A. G.; Cliver, E. W.
In the current paradigm for the modulation of galactic cosmic rays (GCRs), diffusion is taken to be the dominant process during solar maxima while drift dominates at minima. Observations during the recent solar minimum challenge the pre-eminence of drift at such times. In 2009, the ∼2 GV GCR intensity measured by the Newark neutron monitor increas…
Solar Wind Conditions and Composition During the Genesis Mission as Measured by in situ Spacecraft
Neugebauer, Marcia; Wiens, Roger C.; Zurbuchen, Thomas H. +4 more
We describe the Genesis mission solar-wind sample collection period and the solar wind conditions at the L1 point during this 2.3-year period. In order to relate the solar wind samples to solar composition, the conditions under which the samples were collected must be understood in the context of the long-term solar wind. We find that the state of…
Cosmic Rays Through the Solar Hale Cycle. Insights from Ulysses
Heber, B.
The Ulysses spacecraft had been the first to orbit the Sun over its poles and to explore the heliosphere at these high heliolatitudes. It has now completed three fast latitude scans, two at solar minimum and one at solar maximum. Since its launch in October 1990, this mission has led to several surprising discoveries concerning energetic particles…
The Heliospheric Magnetic Field
Balogh, André; Erdõs, Géza
The Heliospheric Magnetic Field (HMF) is the physical framework in which energetic particles and cosmic rays propagate. Changes in the large scale structure of the magnetic field lead to short- and long term changes in cosmic ray intensities, in particular in anti-phase with solar activity. The origin of the HMF in the corona is well understood an…