SM038-06
Driving of outer belt electron loss by solar wind dynamic pressure structures: Analysis of balloon and satellite data

Monday, 14 December 2020: 20:50
Virtual
Aaron W Breneman1, Alexa Jean Halford2, Robyn M Millan3, Leslie A Woodger4, Xiaojia Zhang5, Jasmine Kaur Sandhu6, Luisa Capannolo7, Wen Li7, Qianli Ma7, Christopher M Cully8 and Kyle R Murphy2, (1)The University of Minnesota, Minneapolis, MN, United States, (2)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (3)Dartmouth College, Department of Physics and Astronomy, Hanover, NH, United States, (4)Dartmouth College, Physics & Astronomy, Hanover, NH, United States, (5)IGPP, UCLA, Los Angeles, CA, United States, (6)University of Leicester, Leicester, United Kingdom, (7)Boston University, Boston, MA, United States, (8)University of Calgary, Calgary, AB, Canada
Recorded Presentation
Abstract:
We present observations of ~10-60 min solar wind dynamic pressure structures that drive large-scale coherent ~20-100 keV electron loss from the outer radiation belt. A combination of simultaneous satellite and BARREL balloon observations on Jan 11-12, 2014 show a close association between the pressure structures and precipitation as inferred from balloon X-rays. Specifically, the structures drive radial ExB transport of electrons up to 3 Earth radii, modulating the free electron energy available for low frequency plasmaspheric hiss growth, and subsequent hiss-induced loss cone scattering. The dynamic pressure structures, originating near the Sun and commonly observed advecting with the solar wind, are thus able to switch on scattering loss of electrons by hiss over a large spatial scale. Our results provide a direct link between solar wind pressure fluctuations and modulation of electron loss from the outer radiation belt and may explain long-period modulations and large-scale coherence of X-rays commonly observed in the BARREL dataset.
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