Biblio

Found 3 results
Filters: Author is Malaspina, D.  [Clear All Filters]
2019
Authors: Tyler E., Breneman A., Cattell C., Wygant J, Thaller S., et al.
Title: Statistical occurrence and distribution of high amplitude whistler-mode waves in the outer radiation belt
Abstract: We present the first statistical analysis with continuous data coverage and non‐averaged amplitudes of the prevalence and distribution of high‐amplitude (> 5 mV/m) whistler‐mode waves in the outer radiation belt using 5 years of Van Allen Probes data. These waves are most common above L=3.5 and between MLT of 0‐7 where they are present 1‐4% of the time. During high geomagnetic activity, high‐amplitude whistler‐mode wave occurrence rises above 30% in some regions. During these active times the plasmasphere erodes to lower L and high‐amplitude waves are observed at all L outside of it, with the highest occurrence at low L (3.5‐4) in the pre‐dawn sector. These results have important implications for modeling radiation belt particle interactions with chorus, as large‐amp. . .
Date: 02/2019 Publisher: Geophysical Research Letters DOI: 10.1029/2019GL082292 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019GL082292
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2015
Authors: Breneman A. W., Halford A., Millan R., McCarthy M., Fennell J, et al.
Title: Global-scale coherence modulation of radiation-belt electron loss from plasmaspheric hiss
Abstract: Over 40 years ago it was suggested that electron loss in the region of the radiation belts that overlaps with the region of high plasma density called the plasmasphere, within four to five Earth radii1, 2, arises largely from interaction with an electromagnetic plasma wave called plasmaspheric hiss3, 4, 5. This interaction strongly influences the evolution of the radiation belts during a geomagnetic storm, and over the course of many hours to days helps to return the radiation-belt structure to its ‘quiet’ pre-storm configuration. Observations have shown that the long-term electron-loss rate is consistent with this theory but the temporal and spatial dynamics of the loss process remain to be directly verified. Here we report simultaneous measurements of structured radiation-belt electr. . .
Date: 06/2015 Publisher: Nature Pages: 193 - 195 DOI: 10.1038/nature14515 Available at: http://www.nature.com/doifinder/10.1038/nature14515
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2014
Authors: Califf S., Li X, Blum L., Jaynes A., Schiller Q., et al.
Title: THEMIS measurements of quasi-static electric fields in the inner magnetosphere
Abstract: We use four years of THEMIS double-probe measurements to offer, for the first time, a complete picture of the dawn-dusk electric field covering all local times and radial distances in the inner magnetosphere based on in situ equatorial observations. This study is motivated by the results from the CRRES mission, which revealed a local maximum in the electric field developing near Earth during storm times, rather than the expected enhancement at higher L shells that is shielded near Earth as suggested by the Volland-Stern model. The CRRES observations were limited to the dusk side, while THEMIS provides complete local time coverage. We show strong agreement with the CRRES results on the dusk side, with a local maximum near L =4 for moderate levels of geomagnetic activity and evidence of stro. . .
Date: 10/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA020360 Available at: http://doi.wiley.com/10.1002/2014JA020360
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