Nonlinearity in chorus waves during a geomagnetic storm on 1 November 2012

Journal Article · Fri Jan 08 00:00:00 EST 2016 · Journal of Geophysical Research. Space Physics

DOI:https://doi.org/10.1002/2015JA021772· OSTI ID:1492527

Matsui, Hiroshi ^[1]; Paulson, K. W. ^[1]; Torbert, R. B. ^[1]; Spence, H. E. ^[1]; Kletzing, C. A. ^[2]; Kurth, W. S. ^[2]; Skoug, Ruth M. ^[3]; Larsen, Brian Arthur ^[3]; Breneman, A. W. ^[4]

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1. Univ. of New Hampshire, Durham, NH (United States)
2. Univ. of Iowa, Iowa City, IA (United States)
3. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
4. Univ. of Minnesota, Minneapolis, MN (United States)

In this study, we investigate the possibility of nonlinearity in chorus waves during a geomagnetic storm on 1 November 2012. The data we use were measured by the Van Allen Probe B. Wave data and plasma sheet electron data are analyzed. Chorus waves were frequently measured in the morning side during the main phase of this storm. Large–amplitude chorus waves were seen of the order of ~0.6 nT and >7 mV/m, which are similar to or larger than the typical ULF waves. The waves quite often consist of rising tones during the burst sampling. Since the rising tone is known as a signature of nonlinearity, a large portion of the waves are regarded as nonlinear at least during the burst sampling periods. These results underline the importance of nonlinearity in the dynamics of chorus waves. We further compare the measurement and the nonlinear theories, based on the inhomogeneity ratio, our own calculation derived from the field equation and the backward wave oscillator model. The wave quantities examined are frequency, amplitude, frequency drift rate, and duration. Furthermore, this type of study is useful to more deeply understand wave-particle interactions and hence may lead to predicting the generation and loss of radiation belt electrons in the future.

• Research Organization: Los Alamos National Laboratory (LANL)
• Sponsoring Organization: NASA; USDOE
• Grant/Contract Number: 89233218CNA000001
• OSTI ID: 1492527
• Report Number(s): LA-UR-15-25434
• Journal Information: Journal of Geophysical Research. Space Physics, Journal Name: Journal of Geophysical Research. Space Physics Journal Issue: 1 Vol. 121; ISSN 2169-9380
• Publisher: American Geophysical Union
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
Heliospheric and Magnetospheric Physics