Contemporaneous EMIC and whistler mode waves: Observations and consequences for MeV electron loss. Issue 16 (19th August 2017)

• Record Type: Journal Article
• Authors: Zhang, X.‐J.; Mourenas, D.; Artemyev, A. V.; Angelopoulos, V.; Thorne, R. M.
• Is Part Of: Geophysical research letters. Volume 44:Issue 16(2017)
• Page Start: 8113
• Page End: 8121
• Publication Date: 2017-08-19
• Subjects: relativistic electron loss -- EMIC waves -- whistler mode waves -- wave particle interaction -- electron lifetime -- radiation belts; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2017GL073886
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: The high variability of relativistic (MeV) electron fluxes in the Earth's radiation belts is partly controlled by loss processes involving resonant interactions with electromagnetic ion cyclotron (EMIC) and whistler mode waves. But as previous statistical models were generated independently for each wave mode, whether simultaneous electron scattering by the two wave types has global importance remains an open question. Using >3 years of simultaneous Van Allen Probes and THEMIS measurements, we explore the contemporaneous presence of EMIC and whistler mode waves in the same L shell, albeit at different local times, determining the distribution of wave and plasma parameters as a function of L, K p, and A E . We derive electron lifetimes from observations and provide the first statistics of combined effects of EMIC and whistler mode wave scattering on MeV electrons as a function of L and geomagnetic activity. We show that MeV electron lifetimes are often strongly reduced by such combined scattering. Key Points: Statistics of simultaneous EMIC and whistler mode wave observations Observations and estimates of combined EMIC‐whistler wave effects on MeV electrons Combined hiss and EMIC scattering results in MeV electron lifetime reduction in 30% of the events