Periodic Rising and Falling Tone ECH Waves from Van Allen Probes Observations

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Abstract
AbstractElectron cyclotron harmonic (ECH) waves are known to precipitate plasma sheet electrons into the upper atmosphere and generate diffuse aurorae. In this study, we report quasi-periodic rising (3 events) and falling tone (22 events) ECH waves observed by Van Allen Probes, and evaluate their properties. These rising and falling tone ECH waves prefer to occur during quiet geomagnetic conditions over the dusk to midnight sector in relatively high-density (10–80 cm-3) regions. Their repetition periods increase with increasing L shell at L < 6, ranging from ∼60 to 110 s. The wave element duration varies from 10 s to 130 s peaking at ∼40 s and the chirping rate peaks at ∼50 (∼-50) Hz/s for rising (falling) tones. Our findings reveal intriguing features of the ECH wave properties, which provide new insights into their generation and potential effects on electron precipitation.
Notes
Year of Publication
2021
Journal
Geophysical Research Letters
Volume
n/a
Number
Number of Pages
e2020GL091330
Date Published
02/2021
URL
https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020GL091330
DOI
https://doi.org/10.1029/2020GL091330