Journal article
Energetic electron precipitation characteristics observed from Antarctica during a flux dropout event
Journal of geophysical research. Space physics, Vol.118(11), pp.6921-6935
11/2013
DOI: 10.1002/2013JA019067
Abstract
Data from two autonomous VLF radio receiver systems installed in a remote region of the Antarctic in 2012 is used to take advantage of the juxtaposition of the L=4.6 contour, and the Hawaii-Halley, Antarctica, great circle path as it passes over thick Antarctic ice shelf. The ice sheet conductivity leads to high sensitivity to changing D region conditions, and the quasi constant L shell highlights outer radiation belt processes. The ground-based instruments observed several energetic electron precipitation events over a moderately active 24 h period, during which the outer radiation belt electron flux declined at most energies and subsequently recovered. Combining the ground-based data with low and geosynchronous orbiting satellite observations on 27 February 2012, different driving mechanisms were observed for three precipitation events with clear signatures in phase space density and electron anisotropy. Comparison between flux measurements made by Polar-orbiting Operational Environmental Satellites (POES) in low Earth orbit and by the Antarctic instrumentation provides evidence of different cases of weak and strong diffusion into the bounce loss cone, helping to understand the physical mechanisms controlling the precipitation of energetic electrons into the atmosphere. Strong diffusion events occurred as the <600 keV fluxes began to recover as a result of adiabatic transport of electrons. One event appeared to have a factor of about 10 to 100 times more flux than was reported by POES, consistent with weak diffusion into the bounce loss cone. Two events had a factor of about 3 to 10 times more >30 keV flux than was reported by POES, more consistent with strong diffusion conditions.
Details
- Title: Subtitle
- Energetic electron precipitation characteristics observed from Antarctica during a flux dropout event
- Creators
- Mark A. Clilverd - British Antarctic SurveyNeil Cobbett - British Antarctic SurveyCraig J. Rodger - University of OtagoJames B. Brundell - University of OtagoMichael H. Denton - Lancaster UniversityDavid P. Hartley - Lancaster UniversityJuan V. Rodriguez - Cooperative Institute for Research in Environmental SciencesDonald Danskin - Natural Resources CanadaTero Raita - University of OuluEmma L. Spanswick - University of Calgary
- Resource Type
- Journal article
- Publication Details
- Journal of geophysical research. Space physics, Vol.118(11), pp.6921-6935
- Publisher
- Amer Geophysical Union
- DOI
- 10.1002/2013JA019067
- ISSN
- 2169-9380
- eISSN
- 2169-9402
- Number of pages
- 15
- Grant note
- NE/H014888/1 / Natural Environment Research Council; UK Research & Innovation (UKRI); Natural Environment Research Council (NERC) New Zealand Marsden Fund; Royal Society of New Zealand; Marsden Fund (NZ) ST/I000801/1 / Science and Technology Facilities Council; UK Research & Innovation (UKRI); Science & Technology Facilities Council (STFC) GOES-R Risk Reduction Program NE/H014888/1 / NERC; UK Research & Innovation (UKRI); Natural Environment Research Council (NERC) AFI/11/22 / Natural Environmental Research Council under the Antarctic Funding Initiative STFC PhD Studentship; UK Research & Innovation (UKRI); Science & Technology Facilities Council (STFC) ST/I000801/1 / STFC; UK Research & Innovation (UKRI); Science & Technology Facilities Council (STFC)
- Language
- English
- Date published
- 11/2013
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984548858302771
Metrics
2 Record Views