Electron Diffusion by Magnetosonic Waves in the Earth's Radiation Belts
We conduct a global survey of magnetosonic waves and compute the associated bounce and drift averaged diffusion coefficients, taking into account co-located measurements of fpe/fce, to assess the role of magnetosonic waves in radiation belt dynamics, where fpe is the plasma frequency and fce is the electron gyrofrequency.. The average magnetosonic wave intensities increase with increasing geomagnetic activity and decreasing relative frequency with the majority of the wave power in the range fcp < f < 0.3fLHR during active conditions, where fcp is the proton gyrofrequency and fLHR is the lower hybrid resonance frequency. In the region 4.0 <= L* <= 5.0, the bounce and drift averaged energy diffusion rates due to magnetosonic waves never exceed those due to whistler mode chorus, suggesting that whistler mode chorus is the dominant mode for electron energisation to relativistic energies in this region. Further in, in the region 2.0 <= L* <= 3.5, the bounce and drift averaged pitch angle diffusion rates due to magnetosonic waves can exceed those due to plasmaspheric hiss and very low frequency (VLF) transmitters over energy-dependent ranges of intermediate pitch angles. We compute electron lifetimes by solving the 1D pitch angle diffusion equation including the effects of plasmaspheric hiss, VLF transmitters and magnetosonic waves. We find that magnetosonic waves can have a significant effect on electron loss timescales in the slot region reducing the loss timescales during active times from 5.6 to 1.5 days for 500 keV electrons at L* = 2.5 and from 140.4 days to 35.7 days for 1 MeV electrons at L* = 2.0.
The research leading to these results has received funding from the Natural Environment Research Council (NERC) Highlight Topic grant NE/P01738X/1 (Rad-Sat) and the NERC grants NE/V00249X/1 (Sat-Risk) and NE/R016038/1.
Simple
- Alternate title
- Polar Data Centre (PDC) record GB/NERC/BAS/PDC/01628
- Date (Publication)
- 2022-03-30
- Identifier
- http://www.antarctica.ac.uk/dms/metadata.php?id= / GB/NERC/BAS/PDC/01628
- Maintenance and update frequency
- unknown Unknown
- Keywords
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- NDGO0001
- NERC OAI Harvesting
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- NERC_DDC
- GCMD Parameter Valids
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- EARTH SCIENCE > Sun-earth Interactions > Ionosphere/Magnetosphere Dynamics
- BAS Free-text keywords
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- Electron Diffusion
- Magnetosonic Waves
- Radiation Belts
- Use limitation
- This data is supplied under Open Government Licence v3.0 http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/.
- Access constraints
- otherRestrictions Other restrictions
- Other constraints
- This data is supplied under Open Government Licence v3.0 http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/.
- Metadata language
- EnglishEnglish
- Topic category
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- Climatology, meteorology, atmosphere
- Begin date
- 2012-10-01
- End date
- 2019-10-31
- Reference system identifier
- OGP / urn:ogc:def:crs:EPSG::4326
- Distribution format
-
- Hierarchy level
- dataset Dataset
Domain consistency
- Measure identification
- INSPIRE / Conformity_001
Conformance result
- Date
- Explanation
- See the referenced specification
- Pass
- No
- Statement
- The wave data have been calibrated and quality-controlled prior to release. We also omitted data during thruster firing, eclipse and charging times.
- File identifier
- GB_NERC_BAS_PDC_01628 XML
- Metadata language
- EnglishEnglish
- Hierarchy level
- dataset Dataset
- Date stamp
- 2022-03-30
- Metadata standard name
- NERC profile of ISO19115:2003
- Metadata standard version
- 1.0