Effects of Interplanetary Structures on the Earth’s Outer Radiation Belt Dynamics Observed During September 12-26, 2014: I) Coronal Mass Ejection

Tuesday, 15 December 2015
Poster Hall (Moscone South)
Livia Ribeiro Alves1, Ligia Alves Da Silva2, Vitor Moura Cardoso e Silva Souza3, David G Sibeck4, Paulo Ricardo Jauer5, Luis Eduardo A Vieira3, Brian Walsh6, Marcos Dias Silveira7, Jose Marchezi3, Marlos Rockenbach3, Alisson Dal Lago3, Odim Mendes Jr8, Bruce Tsurutani9, Daiki Koga3, Shrikanth G Kanekal10, Daniel N. Baker11, John R Wygant12 and Craig Kletzing13, (1)INPE National Institute for Space Research, Space Science Division, Sao Jose dos Campos, Brazil, (2)Inst Nac Pesquisas Espaciais, Sao José dos Campos, Brazil, (3)INPE National Institute for Space Research, Sao Jose dos Campos, Brazil, (4)NASA/GSFC, Greenbelt, MD, United States, (5)Inst Nac Pesquisas Espaciais, são josé dos campos - SP, Brazil, (6)University of California Berkeley, Space Sciences Laboratory, Berkeley, CA, United States, (7)INPE National Institute for Space Research, São José dos Campos, Brazil, (8)INPE National Institute for Space Research, Sao Jose Dos Campos, Brazil, (9)NASA Jet Propulsion Laboratory, Pasadena, CA, United States, (10)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (11)University of Colorado at Boulder, Boulder, CO, United States, (12)University of Minnesota Twin Cities, Minneapolis, MN, United States, (13)University of Iowa, Iowa City, IA, United States
Solar wind variations and magnetospheric processes result in a dynamic electron population within the outer Van Allen radiation belt, where electron energies range from several 10’s to several 1000’s KeV . Geomagnetic storms and various solar wind-magnetosphere interaction processes including convection cause both dramatic particle flux increase or decreases. Here we analyze the occurrence of a drop out of ~ 0.04 – 4.5 MeV electron fluxes measured by NASA's Van Allen Probes, THEMIS and NOAA’s GOES during a magnetic cloud-driven geomagnetic storm which started at September 12, 2014. The ~3-day storm left a steady low flux of outer belt energetic electrons that lasted for twelve days (Figure 1). At higher energy levels, electron fluxes decreased by ~1 order of magnitude throughout the vast region from L* ~3 to 6.6. Simulation of a 2 MeV relativistic electron orbit, with 90◦ pitch angle, during the most compressed magnetosphere period shows that magnetopause shadowing can be responsible for the electron dropout observed at radial distances larger than ~ 6 RE). Wave-particle interaction are associated with loss occurring at L < 4. We discuss the solar wind drivers, in particular the contribution of the magnetic cloud parameters for magnetospheric dynamics during the whole period analyzed, i.e., September 13-24, 2014.