A new approach to constructing models of electron diffusion by EMIC waves in the radiation belts

Ross, J.P.J. ORCID: https://orcid.org/0000-0001-5282-3293; Glauert, S.A. ORCID: https://orcid.org/0000-0003-0149-8608; Horne, R.B. ORCID: https://orcid.org/0000-0002-0412-6407; Watt, C.E.; Meredith, N.P ORCID: https://orcid.org/0000-0001-5032-3463; Woodfield, E.E. ORCID: https://orcid.org/0000-0002-0531-8814. 2020 A new approach to constructing models of electron diffusion by EMIC waves in the radiation belts. Geophysical Research Letters, 47 (20), e2020GL088976. 11, pp. https://doi.org/10.1029/2020GL088976

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Abstract/Summary

Electromagnetic Ion Cyclotron (EMIC) waves play an important role in relativistic electron losses in the radiation belts through diffusion via resonant wave‐particle interactions. We present a new approach for calculating bounce and drift‐averaged EMIC electron diffusion coefficients. We calculate bounce‐averaged diffusion coefficients, using quasi‐linear theory, for each individual CRRES EMIC wave observation using fitted wave properties, the plasma density and the background magnetic field. These calculations are then combined into bounce‐averaged diffusion coefficients. The resulting coefficients therefore capture the combined effects of individual spectra and plasma properties as opposed to previous approaches that use average spectral and plasma properties, resulting in diffusion over a wider range of energies and pitch‐angles. These calculations, and their role in radiation belt simulations, are then compared against existing diffusion models. The new diffusion coefficients are found to significantly improve the agreement between the calculated decay of relativistic electrons and Van Allen Probes data.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1029/2020GL088976
ISSN:	0094-8276
Additional Keywords:	radiation belts, EMIC waves, electron diffusion
Date made live:	08 Oct 2020 14:20 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/527805

Item Type:

Publication - Article

Digital Object Identifier (DOI):

https://doi.org/10.1029/2020GL088976

ISSN:

0094-8276

Additional Keywords:

radiation belts, EMIC waves, electron diffusion

Date made live:

08 Oct 2020 14:20 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/527805