A case study of electron precipitation fluxes due to plasmas

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TitleA case study of electron precipitation fluxes due to plasmaspheric hissAbstractWe find that during a large geomagnetic storm in October 2011 the trapped fluxes of >30, >100, and >300 keV outer radiation belt electrons were enhanced at L = 3-4 during the storm main phase. A gradual decay of the trapped fluxes was observed over the following 5-7 days, even though no significant precipitation fluxes could be observed in the Polar Orbiting Environmental Satellite (POES) electron precipitation detectors. We use the Antarctic-Arctic Radiation-belt (Dynamic) Deposition-VLF Atmospheric Research Konsortium receiver network to investigate the characteristics of the electron precipitation throughout the storm period. Weak electron precipitation was observed on the dayside for 5-7 days, consistent with being driven by plasmaspheric hiss. Using a previously published plasmaspheric hiss-induced electron energy e-folding spectrum of E0 = 365 keV, the observed radio wave perturbation levels at L = 3-4 were found to be caused by >30 keV electron precipitation with flux ~100 el cm-2 s-1 sr-1. The low levels of precipitation explain the lack of response of the POES telescopes to the flux, because of the effect of the POES lower sensitivity limit and ability to measure weak diffusion-driven precipitation. The detection of dayside, inner plasmasphere electron precipitation during the recovery phase of the storm is consistent with plasmaspheric hiss wave-particle interactions and shows that the waves can be a significant influence on the evolution of the outer radiation belt trapped flux that resides inside the plasmapause.
©2015. American Geophysical Union. All Rights Reserved.AcknowledgementsThe observations obtained, and research leading to these results, has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under PLASMON grant agreement 263218. R.H.H. also acknowledges the PLASMON grant 263218 to the University of Washington. Data for this paper are available at the British Antarctic Survey Polar Data Centre (http://psddb.nerc-bas.ac.uk/data/access/). C.J.R. was partly supported by the New Zealand Marsden Fund. M.A.C., R.L.H., and R.D. would also like to acknowledge NERC funding as part of the Space Weather and Atmosphere Programme at the British Antarctic Survey. M. Balikhin thanks the reviewers for their assistance in evaluating this paper.

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1st AuthorHardman, R.AuthorHardman, R.Clilverd, M.Rodger, C.Brundell, J.Duthie, R.Holzworth, R.Mann, I.Milling, D.Macusova, E.Year2015JournalJournal of Geophysical Research A: Space PhysicsVolume120Number8Pages6736-6748DOI10.1002/2015JA021429URLhttps://www.scopus.com/inward/recor.....0f61caa0180992bce9666f17fKeywordsrank3Author Keywordselectron precipitationplasmasphereplasmaspheric hissradiation belt electronsProgrammeK060 - AARDDVARK - Long Range Environmental Monitoring by Radio

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TypeArticleCitationHardman, R., Clilverd, M., Rodger, C., Brundell, J., Duthie, R., Holzworth, R., Mann, I., Milling, D. and Macusova, E. (2015). A case study of electron precipitation fluxes due to plasmaspheric hiss. Journal of Geophysical Research A: Space Physics, 120(8): 6736-6748