Journal article
Statistical properties of plasmaspheric hiss from Van Allen Probes observations
Journal of geophysical research. Space physics, Vol.123(4), pp.2605-2619
04/01/2018
DOI: 10.1002/2017JA024593
Abstract
Van Allen Probes observations are used to statistically investigate plasmaspheric hiss wave properties. This analysis shows that the wave normal direction of plasmaspheric hiss is predominantly field aligned at larger L shells, with a bimodal distribution, consisting of a near‐field aligned and a highly oblique component, becoming apparent at lower L shells. Investigation of this oblique population reveals that it is most prevalent at L < 3, frequencies with f/fce>0.01 (or f > 700 Hz), low geomagnetic activity levels, and between 1900 and 0900 magnetic local time. This structure is similar to that reported for oblique chorus waves in the equatorial region, perhaps suggesting a causal link between the two wave modes. Ray tracing results from HOTRAY confirm that it is feasible for these oblique chorus waves to be a source of the observed oblique plasmaspheric hiss population. The decrease in oblique plasmaspheric hiss occurrence rates during more elevated geomagnetic activity levels may be attributed to the increase in Landau resonant electrons causing oblique chorus waves to be more substantially damped outside of the plasmasphere. In turn, this restricts the amount of wave power that can access the plasmasphere and evolve into oblique plasmaspheric hiss. These results confirm that, despite the difference in location of this bimodal distribution compared to previous studies, a direct link between oblique equatorial chorus outside of the plasmasphere and oblique hiss at low L shells is plausible. As such, these results are in keeping with the existing theory of chorus as the source of plasmaspheric hiss.
Details
- Title: Subtitle
- Statistical properties of plasmaspheric hiss from Van Allen Probes observations
- Creators
- David P Hartley - University of IowaCraig A Kletzing - University of IowaOndrej Santolik - Charles UniversityLunjin Chen - University of Texas at DallasRichard B Horne - British Antarctic Survey
- Resource Type
- Journal article
- Publication Details
- Journal of geophysical research. Space physics, Vol.123(4), pp.2605-2619
- Publisher
- American Geophysical Union
- DOI
- 10.1002/2017JA024593
- ISSN
- 2169-9380
- eISSN
- 2169-9402
- Grant note
- DOI: 10.13039/100000104, name: National Aeronautics and Space Administration, award: NAS5-01072, LTAUSA17070, GACR17-07027S; DOI: 10.13039/100003187, name: National Sleep Foundation, award: 1405041; DOI: 10.13039/501100000270, name: Natural Environment Research Council, award: NE/P01738X/1
- Language
- English
- Date published
- 04/01/2018
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984199956202771
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