Estimating Inner Magnetospheric Radial Diffusion Using a Hybrid-Vlasov Simulation

Show full item record



George , H , Osmane , A , Kilpua , E K J , Lejosne , S , Turc , L , Grandin , M , Kalliokoski , M M H , Hoilijoki , S , Ganse , U , Alho , M , Battarbee , M , Bussov , M , Dubart , M , Johlander , A , Manglayev , T , Papadakis , K , Pfau-Kempf , Y , Suni , J , Tarvus , V , Zhou , H & Palmroth , M 2022 , ' Estimating Inner Magnetospheric Radial Diffusion Using a Hybrid-Vlasov Simulation ' , Frontiers in Astronomy and Space Sciences , vol. 9 , 866455 .

Title: Estimating Inner Magnetospheric Radial Diffusion Using a Hybrid-Vlasov Simulation
Author: George, H.; Osmane, A.; Kilpua, E. K. J.; Lejosne, S.; Turc, L.; Grandin, M.; Kalliokoski, M. M. H.; Hoilijoki, S.; Ganse, U.; Alho, M.; Battarbee, M.; Bussov, M.; Dubart, M.; Johlander, A.; Manglayev, T.; Papadakis, K.; Pfau-Kempf, Y.; Suni, J.; Tarvus, V.; Zhou, H.; Palmroth, M.
Contributor organization: Particle Physics and Astrophysics
Space Physics Research Group
Department of Physics
Date: 2022-05-18
Language: eng
Number of pages: 17
Belongs to series: Frontiers in Astronomy and Space Sciences
ISSN: 2296-987X
Abstract: Radial diffusion coefficients quantify non-adiabatic transport of energetic particles by electromagnetic field fluctuations in planetary radiation belts. Theoretically, radial diffusion occurs for an ensemble of particles that experience irreversible violation of their third adiabatic invariant, which is equivalent to a change in their Roederer L* parameter. Thus, the Roederer L* coordinate is the fundamental quantity from which radial diffusion coefficients can be computed. In this study, we present a methodology to calculate the Lagrangian derivative of L* from global magnetospheric simulations, and test it with an application to Vlasiator, a hybrid-Vlasov model of near-Earth space. We use a Hamiltonian formalism for particles confined to closed drift shells with conserved first and second adiabatic invariants to compute changes in the guiding center drift paths due to electric and magnetic field fluctuations. We investigate the feasibility of this methodology by computing the time derivative of L* for an equatorial ultrarelativistic electron population travelling along four guiding center drift paths in the outer radiation belt during a 5 minute portion of a Vlasiator simulation. Radial diffusion in this simulation is primarily driven by ultralow frequency waves in the Pc3 range (10-45 s period range) that are generated in the foreshock and transmitted through the magnetopause to the outer radiation belt environment. Our results show that an alternative methodology to compute detailed radial diffusion transport is now available and could form the basis for comparison studies between numerical and observational measurements of radial transport in the Earth's radiation belts.
Subject: 115 Astronomy, Space science
114 Physical sciences
Peer reviewed: Yes
Rights: cc_by
Usage restriction: openAccess
Self-archived version: publishedVersion

Files in this item

Total number of downloads: Loading...

Files Size Format View
fspas_09_866455.pdf 29.53Mb PDF View/Open

This item appears in the following Collection(s)

Show full item record