Parametrization of coefficients for sub-grid modeling of pitch-angle diffusion in global magnetospheric hybrid-Vlasov simulations

Sub-grid models are key tools to accurately describe the physical processes at play in a system when high-resolution simulations are not feasible. We previously developed a sub-grid model for pitch-angle diffusion in hybrid-Vlasov simulations of Earth's magnetosphere. However, a more precise de...

Full description

Saved in:
Bibliographic Details
Published in:Physics of plasmas 2023-12, Vol.30 (12)
Main Authors: Dubart, M., Battarbee, M., Ganse, U., Osmane, A., Spanier, F., Suni, J., Cozzani, G., Horaites, K., Papadakis, K., Pfau-Kempf, Y., Tarvus, V., Palmroth, M.
Format: Article
Language:English
Subjects:
Anisotropy
Diffusion coefficient
Distribution functions
Earth magnetosphere
Ion temperature
Mathematical models
Parameterization
Pitch (inclination)
Plasma physics
Simulation
Citations: Items that this one cites
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Sub-grid models are key tools to accurately describe the physical processes at play in a system when high-resolution simulations are not feasible. We previously developed a sub-grid model for pitch-angle diffusion in hybrid-Vlasov simulations of Earth's magnetosphere. However, a more precise description of the pitch-angle diffusion coefficient is required to apply this model to global simulations. In this study, we use an existing method to parametrize pitch-angle diffusion coefficients from monotonic distribution functions and adapt it to bi-Maxwellian distributions. We determine these coefficients for various values of the ion temperature anisotropy and plasma β ∥ . We use these newly parametrized coefficients in our sub-grid model and show that it accurately models reduction of temperature anisotropy in both local simulations and global simulations of the Earth's magnetosphere, while using minimal computational resources.
ISSN:1070-664X
1089-7674
DOI:10.1063/5.0176376