Journal article
The Response of Earth's Electron Radiation Belts to Geomagnetic Storms: Statistics From the Van Allen Probes Era Including Effects From Different Storm Drivers
Journal of geophysical research. Space physics, Vol.124(2), pp.1013-1034
02/01/2019
DOI: 10.1029/2018JA026066
Abstract
A statistical study was conducted of Earth's radiation belt electron response to geomagnetic storms using NASA's Van Allen Probes mission. Data for electrons with energies ranging from 30 keV to 6.3 MeV were included and examined as a function of L-shell, energy, and epoch time during 110 storms with SYM-H <=-50 nT during September 2012 to September 2017 (inclusive). The radiation belt response revealed clear energy and L-shell dependencies, with tens of keV electrons enhanced at all L-shells (2.5 <= L <= 6) in all storms during the storm commencement and main phase and then quickly decaying away during the early recovery phase, low hundreds of keV electrons enhanced at lower L-shells (similar to 3 <= L <= similar to 4) in upward of 90% of all storms and then decaying gradually during the recovery phase, and relativistic electrons throughout the outer belt showing main phase dropouts with subsequent and generally unpredictable levels of replenishment during the recovery phase. Compared to prestorm levels, electrons with energies >1 MeV also revealed a marked increase in likelihood of a depletion at all L-shells through the outer belt (3.5 <= L <= 6). Additional statistics were compiled revealing the storm time morphology of the radiation belts, confirming the aforementioned qualitative behavior. Considering storm drivers in the solar wind: storms driven by coronal mass ejection (CME) shocks/sheaths and CME ejecta only are most likely to result in a depletion of >1-MeV electrons throughout the outer belt, while storms driven by full CMEs and stream interaction regions are most likely to produce an enhancement of MeV electrons at lower (L < similar to 5) and higher (L > similar to 4.5) L-shells, respectively. CME sheaths intriguingly result in a distinct enhancement of similar to 1-MeV electrons around L similar to 5.5, and on average, CME sheaths and stream interaction regions result in double outer belt structures.
Details
- Title: Subtitle
- The Response of Earth's Electron Radiation Belts to Geomagnetic Storms: Statistics From the Van Allen Probes Era Including Effects From Different Storm Drivers
- Creators
- D. L. Turner - The Aerospace CorporationE. K. J. Kilpua - University of HelsinkiH. Hietala - Planetary Science InstituteS. G. Claudepierre - The Aerospace CorporationT. P. O'Brien - The Aerospace CorporationJ. F. Fenneill - Aerosp Corp, Space Sci Dept, El Segundo, CA 90245 USAJ. B. Blake - The Aerospace CorporationA. N. Jaynes - University of IowaS. Kanekal - Goddard Space Flight CenterD. N. Baker - University of Colorado BoulderH. E. Spence - University of New HampshireJ-F Ripoll - CEA DAM Île-de-FranceG. D. Reeves - Los Alamos National Laboratory
- Resource Type
- Journal article
- Publication Details
- Journal of geophysical research. Space physics, Vol.124(2), pp.1013-1034
- DOI
- 10.1029/2018JA026066
- ISSN
- 2169-9380
- eISSN
- 2169-9402
- Publisher
- Amer Geophysical Union
- Number of pages
- 22
- Grant note
- 1312390 / Finnish Centre of Excellence in Research of Sustainable Space (Academy of Finland) 4100103 / European Research Council (ERC) under the European Union's Horizon 2020 Research and Innovation Programme Project SolMAG; European Research Council (ERC) NAS5-01072 / NASA; National Aeronautics & Space Administration (NASA) Turku Collegium for Science and Medicine 1310445 / Academy of Finland
- Language
- English
- Date published
- 02/01/2019
- Academic Unit
- Physics and Astronomy; University College Courses
- Record Identifier
- 9984428771202771
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