Verification of SpacePy's radial diffusion radiation belt model

摘要

Model verification, or the process of ensuring that the prescribed equationsare properly solved, is a necessary step in code development. Careful,quantitative verification guides users when selecting grid resolution and timestep and gives confidence to code developers that existing code is properlyinstituted. This workintroduces the RadBelt radiation belt model, a new, open-source versionof the Dynamic Radiation Environment Assimilation Model (DREAM) and uses theMethod of Manufactured Solutions (MMS) to quantitatively verify it. Order ofconvergence is investigated for a plethora of code configurations and sourceterms. The ability to apply many different diffusion coefficients, includingtime constant and time varying, is thoroughly investigated.The model passes all of the tests, demonstrating correct implementationof the numerical solver. The importance of D_LL and source term dynamicson the selection of time step and grid size is also explored. Finally,an alternative method to apply the source term isexamined to illustrate additional considerations required when non-linearsource terms are used.