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Long-term variation in cosmic-ray modulation
(North-West University (South Africa), 2017)
The transport of cosmic rays inside the heliosphere can be described b
the Parker equation (Parker, 1965). Since there are no full analytica solutions to the Parker
equation, two first-order approximate solutions o the ...
An ab initio approach to the heliospheric modulation of galactic cosmic rays
(North-West University, 2006)
In the present study we aim to further our understanding of charged particle transport in a magnetized medium. To this end, we perform direct numerical simulations of particle transport in a turbulent magnetic field. From ...
On the development and applications of a three–dimensional ab initio cosmic–ray modulation model
(North-West University, 2012)
A proper understanding of the effects of turbulence on the diffusion and drift of cosmic-rays in the heliosphere is imperative for a better understanding of cosmic-ray modulation. This study
presents an ab initio model ...
The effect of a Fisk-Parker hybrid magnetic field on cosmic rays in the heliosphere
(North-West University, 2005)
The existence of a Fisk-type heliospheric magnetic field (HMF) is one of the most debated questions in cosmic-ray modulation. Recently, Burger and Hitge [2004] developed a divergence-free Fisk-Parker hybrid magnetic field ...
Effects of termination shock acceleration on cosmic rays in the heliosphere
(North-West University, 2004)
The interest in the role of the solar wind termination shock (TS) and heliosheath in cosmic ray (CR) modulation studies has increased sigm6cantly as the Voyager 1 and 2 spacecraft approach the estimated position of the TS. ...
A study of the time-dependent modulation of cosmic rays in the inner heliosphere
(North-West University, 2010)
A two-dimensional (2-D) time-dependent cosmic ray modulation model is used to calculate the modulation of cosmic-ray protons and electrons for 11-and 22-year modulation cycles using a compound approach to describe solar ...
Cosmic ray modulation processes in the heliosphere
(North-West University, 2011)
The solar minimum of 2009 has been identified as an exceptional event with regard to
cosmic ray (CR)modulation, since conditions in the heliosphere have reached unprecedented
quiet levels. This unique minimum has been ...
The effect of the heliospheric current sheet on cosmic-ray modulation
(North-West University (South Africa), Potchefstroom Campus, 2015)
The heliospheric current sheet is a dominant feature of the heliosphere. As solar activity
increases, the tilt angle of the current sheet increases, and so does the region swept out
by this structure, to cover most of ...
An ab initio approach to the historical modulation of cosmic rays
(North-West University (South Africa), 2021)
The relationship between observed cosmic-ray intensities and the heliospheric magnetic
field during the early space age is generally considered to be anomalous, relative to their
relationship observed at later times. ...
Modelling charge-sign dependent modulation of cosmic rays in the heliosphere
(North-West University (South Africa), 2016)
The solar minimum of cycle 23/24 has seen exceptionally quiet levels of solar activity
and heliospheric modulation, which resulted in the highest cosmic ray (CR) spectrum
ever recorded at Earth in December 2009 by the ...