Speaker
Dr
Xi Luo
(North-West University, Potchefstroom, South Africa)
Description
We have constructed a 3-D numerical model for studying Forbush Decreases (FDs) in the heliosphere. It incorporates 3-D propagation barriers, with enhanced cooling inside, into a time-dependent Parker type modulation model using a Stochastic Differential Equation (SDE) approach. This numerical model simultaneously takes into account the effect of solar wind convection, regular drift plus current sheet drift, parallel and perpendicular diffusion and adiabatic energy changes. This state-of-art numerical model enables us to find and study some new 3-D features for FD type events: 1. The cosmic ray intensity at Earth varies depending on the relative location of the Earth to the current sheet, and is reflected also in the amplitude of the FDs. The local modulation conditions, at a given observational point, determine the total amplitude. 2. The radial, latitudinal and longitudinal extent of a diffusion barrier significantly affects the amplitude of a FD. 3. The recovery time of a FD, at a given observational location, is determined by the modulation conditions which the corresponding propagation barrier encounters as it moves outwards in the heliosphere.
| Registration number following "ICRC2015-I/" | 196 |
|---|---|
| Collaboration | -- not specified -- |
Primary author
Dr
Xi Luo
(North-West University, Potchefstroom, South Africa)
Co-authors
Marthinus Potgieter
(North-West Uiversity)
Prof.
Ming Zhang
(Florida Institute of Technology)
