@InProceedings{FerreiraSilAlvMarDeg:2024:MeReEl,
               author = "Ferreira, Karen J{\'u}lia Coldebella and Silva, Ligia Alves da 
                         and Alves, Livia Ribeiro and Marchezi, Jos{\'e} Paulo and 
                         Deggeroni, Vinicius",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Instituto Nacional de 
                         Pesquisas Espaciais (INPE)} and {Instituto Nacional de Pesquisas 
                         Espaciais (INPE)} and {Instituto Nacional de Pesquisas Espaciais 
                         (INPE)}",
                title = "Mechanisms of Relativistic Electron Flux Dropouts in the Outer 
                         Radiation Belt Following the Occurrence of Supercritical 
                         Interplanetary Quasi-Parallel Shock Waves",
            booktitle = "Proceedings...",
                 year = "2024",
         organization = "Conferencia Latinoamericana de Geof{\'{\i}}sica Espacial, 14.",
             abstract = "Interplanetary shock waves, upon interacting with Earth's 
                         magnetosphere, elicit a complex cascade of responses. A lingering 
                         question pertains to the influence of shock obliquity on electron 
                         population dynamics in the outer radiation belt and the ensuing 
                         variability. This study focuses on the analysis of two specific 
                         case studies involving quasi-parallel supercritical interplanetary 
                         shock waves. The objective is to discern the mechanisms 
                         responsible for the observed dropouts in relativistic electron 
                         flux (1.8 to 3.4 MeV) following these events. The chosen case 
                         studies are part of a comprehensive dataset comprising 118 
                         interplanetary shock waves that transpired during the Van Allen 
                         Probes Era (20122019). Using low beta and high fast Mach number as 
                         criteria, 26 shocks were identified as supercritical. Employing 
                         the mixed modes method of shock normal calculation, 8 shocks were 
                         pinpointed as quasi-parallel. Among them, we selected two events 
                         with dropouts initiating within a maximum of two hours after the 
                         shock arrival. Notably, both events featured dropouts initiated 
                         after the shock that reached 3.5 Earth radii (R_E). Concurrently 
                         with the shock arrival, there is an increase in ULF wave activity, 
                         characterized by a high power spectral density between 0 and 20 
                         mHz in both events. Additionally, we observed an increase in 
                         chorus wave activity, coinciding with the shock arrival in the 
                         first event and 3 hours later in the second event, with both 
                         instances manifesting in the upper-frequency band. Analysis of the 
                         phase space density (PhSD) profiles uncovered a predominance of 
                         the local loss mechanism, driven by Chorus waves in both cases. 
                         Despite notable ULF wave activity following the shock impact, the 
                         majority of these waves were concentrated in the compressional 
                         mode, exhibiting potency levels reaching 10\⁴ nTē/Hz. This 
                         mode is comparatively less conducive to interacting with electrons 
                         in the outer radiation belt than the poloidal mode, which 
                         exhibited potency levels reaching 10ģ nTē/Hz. This disparity 
                         arises from the electric component of the poloidal mode aligning 
                         with the electrons' trajectory, boosting interaction efficacy. 
                         Conversely, in the compressional mode, the electric component is 
                         relatively diminished. Furthermore, the toroidal mode's electric 
                         component is even smaller, placing it outside the scope of this 
                         study. Subsequent steps involve investigating the characteristics 
                         of Chorus waves, including obliquity and planarity, and 
                         calculating radial diffusion coefficients (D_LL). These findings 
                         contribute significantly to comprehending the role of 
                         interplanetary shocks in generating the physical mechanisms 
                         responsible for variability in the outer radiation belt's electron 
                         flux.",
  conference-location = "Monterrey, Mexico",
      conference-year = "08-12 Apr. 2024",
             language = "en",
        urlaccessdate = "19 maio 2024"
}