A new ionospheric electron precipitation module coupled with RAM-SCB within the geospace general circulation model

摘要: Electron precipitation down to the atmosphere due wave-particle scattering in magnetosphere contributes significantly auroral ionospheric conductivity. In order obtain conductivity global MHD models that are incapable of capturing kinetic physics magnetosphere, parameters often used estimate electron flux for calculation. Such an approach, however, lacks self-consistency representing magnetosphere-ionosphere coupling processes. this study we improve processes with a more physical method. We calculate physics-based from ring current and map it altitude solving electrodynamics. particular, use BATS-R-US (Block Adaptive Tree Scheme-Roe type-Upstream) model coupled RAM-SCB (Ring current-Atmosphere interaction Model Self-Consistent Magnetic field (B)) solves pitch angle-dependent distribution functions, circulation dynamics during 25–26 January 2013 storm event. Since loss is mostly governed by resonant further investigate two methods specifying associated interactions: (1) using angle diffusion coefficients Dαα(E,α) determined quasi-linear theory, wave spectral plasma density obtained statistical observations (named as “diffusion coefficient method”) (2) lifetimes τ(E) independent on angles inferred above “lifetime method”). found both demonstrate similar temporal evolution trapped electrons, indicating impact different kinds rates small population. However, precipitated lifetime method hardly captures any large L shell (i.e., 4 < 6.5) region, while produces much better agreement NOAA/POES measurements, including spatial region premidnight through dawn dayside. Further comparisons energy DMSP indicates new approach can explain diffuse sector, such enhanced at latitudes drop near subauroral latitudes, but traditional largely overestimates lower latitudes.