Journal article
In situ observations of Pc1 pearl pulsations by the Van Allen Probes
Geophysical research letters, Vol.41(6), pp.1823-1829
03/28/2014
DOI: 10.1002/2013GL059187
Abstract
We present in situ observations of Pc1 pearl pulsations using the Van Allen Probes. These waves are often observed using ground‐based magnetometers, but are rarely observed by orbiting satellites. With the Van Allen Probes, we have seen at least 14 different pearl pulsation events during the first year of operations. These new in situ measurements allow us to identify the wave classification based on local magnetic field conditions. Additionally, by using two spacecraft, we are able to observe temporal changes in the region of observation. The waves appear to be generated at an overall central frequency, as often observed on the ground, and change polarization from left‐ to right‐handedness as they propagate into a region where they are resonant with the crossover frequency (where R‐ and L‐mode waves have the same phase velocity). By combining both in situ and ground‐based data, we have found that the region satisfying electromagnetic ion cyclotron wave generation conditions is azimuthally large while radially narrow. The observation of a similar modulation period on the ground as in the magnetosphere contradicts the bouncing wave packet mechanism of generation.
Key Points
Pc1 pearl pulsations are found in Van Allen Probe data
Source region can be mapped
They correlate well with ground‐based observations
Details
- Title: Subtitle
- In situ observations of Pc1 pearl pulsations by the Van Allen Probes
- Creators
- K. W Paulson - University of New HampshireC. W Smith - University of New HampshireM. R Lessard - University of New HampshireM. J Engebretson - Augsburg UniversityR. B Torbert - University of New HampshireC. A Kletzing - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Geophysical research letters, Vol.41(6), pp.1823-1829
- DOI
- 10.1002/2013GL059187
- ISSN
- 0094-8276
- eISSN
- 1944-8007
- Number of pages
- 7
- Grant note
- NSF (PLR‐1141987; AGS‐1202827) Augsburg College (ANT‐1142045)
- Language
- English
- Date published
- 03/28/2014
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984199849102771
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