Speaker
Dr
Frederic Effenberger
(Stanford University)
Description
Recent multi-spacecraft Solar Energetic Particle (SEP) observations have challenged the traditional view of SEP production and interplanetary transport. The observations suggest fast SEP access to a wide range of heliographic longitudes. The recent case studies that fit the SEP observations with 3-dimensional diffusive SEP transport simulations suggest a narrow source region, and strong cross-field diffusion beyond that permitted by the current theoretical understanding. Laitinen et al (2013) suggested a new approach to the modelling of interplanetary SEP transport, based on their finding that the cross-field diffusion early in an SEP event is not diffusive. The model incorporates field-line meandering into the Fokker-Planck (FP) transport equation framework. In this presentation, we report on the implementation of the new model within a stochastic differential equation framework for particle transport and field-line wandering. We show how it is able to reproduce the observed fast access of SEPs to wide range of longitudes with realistic interplanetary transport conditions even for a narrow source region. Results of a parametric analysis on how the level of interplanetary turbulence and the SEP source characteristics affect the SEP intensities at at 1 AU are presented, and we discuss the implications for the SEP event origins and the role of interplanetary turbulence in the interpretation of SEP observations.
Author
Dr
Frederic Effenberger
(Stanford University)
Co-authors
Dr
Andreas Kopp
(University Kiel)
Dr
Mike Marsh
(University of Central Lancashire)
Dr
Silvia Dalla
(University of Central Lancashire)
Dr
Timo Laitinen
(University of Central Lancashire)
