Van Allen Probes, THEMIS, GOES, and Cluster observations of EMIC waves, ULF pulsations, and an electron flux dropout

0459490 - ÚFA 2017 RIV US eng J - Článek v odborném periodiku
Sigsbee, K. - Kletzing, C. A. - Smith, C. W. - MacDowall, R. - Spence, H. - Reeves, G. - Blake, J. B. - Baker, D. N. - Green, J. C. - Singer, H. J. - Carr, C. - Santolík, Ondřej
Van Allen Probes, THEMIS, GOES, and Cluster observations of EMIC waves, ULF pulsations, and an electron flux dropout.
Journal of Geophysical Research-Space Physics. Roč. 121, č. 3 (2016), s. 1990-2008. ISSN 2169-9380. E-ISSN 2169-9402
Grant ostatní: AV ČR(CZ) AP1401
Program: Akademická prémie - Praemium Academiae
Institucionální podpora: RVO:68378289
Klíčová slova: EMIC waves * ULF pulsations * electron flux dropouts * Dst effect * magnetopause shadowing * Van Allen Probes
Kód oboru RIV: BL - Fyzika plazmatu a výboje v plynech
Impakt faktor: 2.733, rok: 2016
http://onlinelibrary.wiley.com/doi/10.1002/2014JA020877/full

We examined an electron flux dropout during the 12–14 November 2012 geomagnetic storm using observations from seven spacecraft: the two Van Allen Probes, Time History of Events and Macroscale Interactions during Substorms (THEMIS)-A (P5), Cluster 2, and Geostationary Operational Environmental Satellites (GOES) 13, 14, and 15. The electron fluxes for energies greater than 2.0 MeV observed by GOES 13, 14, and 15 at geosynchronous orbit and by the Van Allen Probes remained at or near instrumental background levels for more than 24 h from 12 to 14 November. For energies of 0.8 MeV, the GOES satellites observed two shorter intervals of reduced electron fluxes. The first interval of reduced 0.8 MeV electron fluxes on 12–13 November was associated with an interplanetary shock and a sudden impulse. Cluster, THEMIS, and GOES observed intense He+ electromagnetic ion cyclotron (EMIC) waves from just inside geosynchronous orbit out to the magnetopause across the dayside to the dusk flank. The second interval of reduced 0.8 MeV electron fluxes on 13–14 November was associated with a solar sector boundary crossing and development of a geomagnetic storm with Dst < −100 nT. At the start of the recovery phase, both the 0.8 and 2.0 MeV electron fluxes finally returned to near prestorm values, possibly in response to strong ultralow frequency (ULF) waves observed by the Van Allen Probes near dawn. A combination of adiabatic effects, losses to the magnetopause, scattering by EMIC waves, and acceleration by ULF waves can explain the observed electron behavior.
Trvalý link: http://hdl.handle.net/11104/0259677