Evidence of stronger pitch angle scattering loss caused by oblique whistler-mode waves as compared with quasi-parallel waves

TitleEvidence of stronger pitch angle scattering loss caused by oblique whistler-mode waves as compared with quasi-parallel waves
Publication TypeJournal Article
Year of Publication2014
AuthorsLi, W, Mourenas, D, Artemyev, A, Agapitov, O, Bortnik, J, Albert, J, Thorne, RM, Ni, B, Kletzing, CA, Kurth, WS, Hospodarsky, GB
JournalGeophysical Research Letters
Paginationn/a - n/a
Date Published08/2014
Keywordschorus waves; electron precipitation; oblique whistler; pitch angle scattering
AbstractWave normal distributions of lower-band whistler-mode waves observed outside the plasmapause exhibit two peaks; one near the parallel direction and the other at very oblique angles. We analyze a number of conjunction events between the Van Allen Probes near the equatorial plane and POES satellites at conjugate low altitudes, where lower-band whistler-mode wave amplitudes were inferred from the two-directional POES electron measurements over 30–100 keV, assuming that these waves were quasi-parallel. For conjunction events, the wave amplitudes inferred from the POES electron measurements were found to be overestimated as compared with the Van Allen Probes measurements primarily for oblique waves and quasi-parallel waves with small wave amplitudes (< ~20 pT) measured at low latitudes. This provides plausible experimental evidence of stronger pitch-angle scattering loss caused by oblique waves than by quasi-parallel waves with the same magnetic wave amplitudes, as predicted by numerical calculations.
URLhttp://doi.wiley.com/10.1002/2014GL061260
DOI10.1002/2014GL061260
Short TitleGeophys. Res. Lett.


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