Browsing Research Output by Author "Potgieter, Marthinus Steenkamp"
Now showing items 119 of 19

Cosmic ray modulation in the outer heliosphere: predictions for cosmic ray intensities up to the heliopause along Voyager 1 and 2 trajectories
Ferreira, Stephanus Esaias Salomon; Potgieter, Marthinus Steenkamp; Manuel, Rex (Elsevier, 2011) 
Cosmic rays in the inner heliosphere: insights from observations, theory and models
Potgieter, Marthinus Steenkamp (Springer, 2011)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 ... 
The dynamic heliosphere, solar activity, and cosmic rays
Potgieter, Marthinus Steenkamp (Elseveier, 2010) 
The heliospheric modulation of cosmic rays: Effects of a latitude dependent solar wind termination shock
Ngobeni, Mabedle Donald; Potgieter, Marthinus Steenkamp (Elseveier, 2010) 
The heliospheric transport and modulation of multiple charged anomalous oxygen revisited
Ferreira, Stephanus Esaias Salomon; Potgieter, Marthinus Steenkamp; Strauss, Roelf Du Toit (EDP Sciences, 2010) 
Modeling anomalous cosmic ray oxygen gradients over successive solar cycles
Potgieter, Marthinus Steenkamp; Strauss, Roelf Du Toit (American Geophysical Union, 2010) 
Modeling ground and space based cosmic ray observations
Ferreira, Stephanus Esaias Salomon; Potgieter, Marthinus Steenkamp; Strauss, Roelf du Toit (Elsevier, 2012)After entering our local astrosphere (called the heliosphere), galactic cosmic rays, as charged particles, are affected by the Sun’s turbulent magnetic field. This causes their intensities to decrease towards the inner ... 
Modeling the acceleration and modulation of anomalous cosmic ray oxygen
Ferreira, Stephanus Esaias Salomon; Potgieter, Marthinus Steenkamp; Strauss, Roelf du Toit (Elsevier, 2011) 
Modeling the modulation of galactic and jovian electrons by stochastic processes
Kopp, Andreas; Potgieter, Marthinus Steenkamp; Strauss, Roelf Du Toit; Büsching, Ingo (IOP Publishing, 2011)We present a newly developed numerical modulation model to study the transport of galactic and Jovian electrons in the heliosphere. The model employs stochastic differential equations (SDEs) to solve the corresponding ... 
Modelling anomalous cosmic ray oxygen in the heliosheath
Ferreira, Stephanus Esaias Salomon; Hill, M E; Potgieter, Marthinus Steenkamp; Strauss, Roelf Du Toit (EDP Sciences, 2010) 
Modelling heliospheric current sheet drift in stochastic cosmic ray transport models
Kopp, Andreas; Potgieter, Marthinus Steenkamp; Strauss, Roelf du Toit; Büsching, Ingo (Springer, 2012)Drifts are one of the major cosmic ray modulation mechanisms in the heliosphere. Three types of drifts occur in the background heliospheric magnetic field, namely curvature, gradient and current sheet drifts. The last ... 
Modelling of galactic carbon in an asymmetrical heliosphere: effects of asymmetrical modulation conditions
Ngobeni, Mabedle Donald; Potgieter, Marthinus Steenkamp (Elsevier, 2012)Observations of galactic cosmic rays (GCRs) from the two Voyager spacecraft inside the heliosheath indicate significant differences between them, suggesting that in addition to a possible global asymmetry in the north–south ... 
Modelling of lowenergy galactic electrons in the heliosheath
Nkosi, Godfrey Sibusiso; Potgieter, Marthinus Steenkamp; Webber, W.R. (Elsevier, 2011) 
Modulation of galactic cosmic rays in a northsouth asymmetrical heliosphere
Ngobeni, Mabedle Donald; Potgieter, Marthinus Steenkamp (Elsevier, 2011) 
On cosmic ray modulation beyond the heliopause: where is the modulation boundary?
Ferreira, Stephanus Esaias Salomon; Potgieter, Marthinus Steenkamp; Scherer, K.; Fichtner, H.; Strauss, Roelf du Toit; Fahr, H.J. (IOP Publications, 2011)Two of the paradigms in modeling the transport of galactic cosmic rays are that the modulation boundary is the heliopause and that the local interstellar spectra are identical to the galactic cosmic ray spectra. Here we ... 
On the propagation times and energy losses of cosmic rays in the heliosphere
Kopp, Andreas; Potgieter, Marthinus Steenkamp; Strauss, Roelf du Toit; Büsching, Ingo (American Geophysical Union, 2011)We present calculations of the propagation times and energy losses of cosmic rays as they are transported through the heliosphere. By calculating these quantities for a spatially 1D scenario, we benchmark our numerical ... 
Possible evidence for a fisktype heliospheric magnetic field, 1: analyzing Ulysses/Ket electron observations
Burger, Renier Adriaan; Engelbrecht, Nicholas Eugene; Ferreira, Stephanus Esaias Salomon; Potgieter, Marthinus Steenkamp; Sternal, O.; Fichtner, H.; Heber, B.; Kopp, A.; Scherer, K. (IOP Publishing, 2011)The propagation of energetic charged particles in the heliospheric magnetic field is one of the fundamental problems in heliophysics. In particular, the structure of the heliospheric magnetic field remains an unsolved ... 
A stochastic differential equation code for multidimensional FokkerPlanck type problems
Kopp, Andreas; Potgieter, Marthinus Steenkamp; Büsching, Ingo; Strauss, Roelf du Toit (Elsevier, 2012)We present a newly developed numerical code that integrates Fokker–Planck type transport equations in four to six spatial dimensions (configuration plus momentum space) and time by means of stochastic differential equations. ... 
Timedependent cosmic ray modulation
Engelbrecht, Nicholas Eugene; Ferreira, Stephanus Esaias Salomon; Potgieter, Marthinus Steenkamp; Strauss, Roelf Du Toit; Manuel, Rex (Elsevier, 2011)