@Article{SilvaATPSLLP:2022:MoRaBe,
               author = "Silva, Graziela Belmira Dias da and Alves, Livia Ribeiro and Tu, 
                         W. and Padilha, Antonio Lopes and Souza, Vitor Moura Cardoso e 
                         Silva and Li, L. F. and Lyu, X. and P{\'a}dua, Marcelo Banik de",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Instituto Nacional de 
                         Pesquisas Espaciais (INPE)} and {} and {} and {Instituto Nacional 
                         de Pesquisas Espaciais (INPE)}",
                title = "Modeling Radiation Belt Electron Dropouts During Moderate 
                         Geomagnetic Storms Using Radial Diffusion Coefficients Estimated 
                         With Global MHD Simulations",
              journal = "Journal of Geophysical Research: Space Physics",
                 year = "2022",
               volume = "127",
               number = "9",
                pages = "e2022JA030602",
                month = "Sept.",
             keywords = "outer radiation belt, flux dropouts, CIRs, MHD simulation, 
                         event-specific D-LL, case studies.",
             abstract = "Main phase flux dropouts often promote depletion of the outer 
                         electron radiation belt. The quantification of the contributions 
                         of various loss mechanisms to MeV electron dropouts has not yet 
                         been elucidated in detailed case studies for moderate geomagnetic 
                         storms. This work focuses on quantifying radial diffusion to study 
                         relativistic electron flux losses observed by Van Allen Probes 
                         during two moderate storms in 2017. The events are identified as 
                         Case 1 (27 March), with losses deep in L, and Case 2 (21 
                         November), with less deep losses. Event-specific radial diffusion 
                         coefficients (D-LL) were calculated from global 
                         magnetohydrodynamic (MHD) fields simulated by the SWMF/BATS-R-US. 
                         The MHD-D-LL was used as an input to radial diffusion simulations 
                         of both events for relativistic electrons. For the outer boundary 
                         conditions defined at L* = 6, electron fluxes measured by GOES-15 
                         at geosynchronous orbit were converted to phase space densities 
                         (PSDs) and then calibrated against the Van Allen Probe A 
                         measurements. Using these calibrated PSD of GOES-15 at the outer 
                         boundary and event-specific MHD-D-LL, the main phase dropout is 
                         well captured with radial diffusion simulation for Case 2, but not 
                         for the deep dropout in Case 1 down to L* < 4.5. Scaling MHD-D-LL 
                         based on validations of the MHD waves against in situ wave 
                         observations improves the simulation results of Case 1, but still 
                         does not fully resolve its deep dropout. However, analyzing the 
                         uncertainty of simulated PSD imposed by the uncertainty in the 
                         scaled MHD-D-LL, it was found that outward radial diffusion could 
                         still account for the losses at L* < 4.5.",
                  doi = "10.1029/2022JA030602",
                  url = "http://dx.doi.org/10.1029/2022JA030602",
                 issn = "2169-9402",
             language = "en",
           targetfile = "JGR Space Physics - 2022 - Silva - Modeling Radiation Belt 
                         Electron Dropouts During Moderate Geomagnetic Storms Using.pdf",
        urlaccessdate = "13 maio 2024"
}