Bayesian Inference of Quasi-Linear Radial Diffusion Parameters using Van Allen Probes

Author
Keywords
Abstract
Abstract The Van Allen radiation belts in the magnetosphere have been extensively studied using models based on radial diffusion theory, which is derived from a quasi-linear approach with prescribed inner and outer boundary conditions. The 1D diffusion model requires the knowledge of a diffusion coefficient and an electron loss timescale, which is typically parameterized in terms of various quantities such as the spatial (L) coordinate or a geomagnetic index (e.g., Kp). These terms are typically empirically derived, not directly measurable, and hence are not known precisely, due to the inherent nonlinearity of the process and the variable boundary conditions. In this work, we demonstrate a probabilistic approach by inferring the values of the diffusion and loss term parameters, along with their uncertainty, in a Bayesian framework, where identification is obtained using the Van Allen Probe measurements. Our results show that the probabilistic approach statistically improves the performance of the model, compared to the empirical parameterization employed in the literature.
Notes
Year of Publication
2020
Journal
Journal of Geophysical Research: Space Physics
Volume
125
Number
Date Published
04/2020
URL
https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019JA027618
DOI
10.1029/2019JA027618