Systematic analysis of equatorial noise below the lower hybrid frequency

By O. Santolík, F. Němec, K. Gereova, E. Macusova, Y. Conchy, N. Cornilleau-Wehrlin. 2004

146 citations recorded by the source corpus.

Abstract. We report results of a systematic analysis of a large number of observations of equatorial noise between the local proton cyclotron frequency and the local lower hybrid frequency. The analysis is based on the data collected by the STAFF-SA instruments on board the four Cluster spacecraft. The data set covers their first two years of measurement in the equatorial magnetosphere at radial distances between 3.9 and 5 Earth radii. Inspection of 781 perigee passages shows that the occurrence rate of equatorial noise is approximately 60%. We identify equatorial noise by selecting data with nearly linearly polarized magnetic field fluctuations. These waves are found within 10° of the geomagnetic equator, consistent with the published past observations. Our results show that equatorial noise has the most intense magnetic field fluctuations among all the natural emissions in the given interval of frequencies and latitudes. Electric field fluctuations of equatorial noise are also more intense compared to the average of all detected waves. Equatorial noise thus can play a non-negligible role in the dynamics of the internal magnetosphere.

Subfields: Astronomy and Astrophysics, Geophysics, Molecular Biology

View Paper: https://www.semanticscholar.org/paper/fa69f279ab8ba0dde7daa2da559470479b96b56a

How researchers see this paper

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In Astronomy and Astrophysics

1. R. Thorne
2. Wen Li
3. Jacob Bortnik
4. M. Hudson
5. J. Fennell
6. Seth G. Claudepierre
7. A. Y. Ukhorskiy
8. R. Horne

In Geophysics

1. Wen Li
2. R. Thorne
3. Jacob Bortnik
4. M. Hudson
5. J. Fennell
6. A. Y. Ukhorskiy
7. Seth G. Claudepierre
8. Xinlin Li

In Molecular Biology

1. R. Thorne
2. Wen Li
3. Jacob Bortnik
4. J. Fennell
5. C. Crabtree
6. Xinlin Li
7. J. Ripoll
8. M. Hudson

Citations in the corpus

• Transit time scattering of energetic electrons due to equatorially confined magnetosonic waves (2010, background): “%) and shown to have the most intense wave electric field compared with all other natural emissions, in the range of CLUSTER equatorial passes (L ∼ 4–5) [Santolík et al., 2004].”
• Earth's Van Allen Radiation Belts: From Discovery to the Van Allen Probes Era (2019, background): “lower‐hybrid resonant frequency and are observed both inside and outside the plasmasphere (Boardsen et al., 2016; Ma et al., 2016b; Nemec et al., 2006; Santolík et al., 2004).”
• Particle Dynamics in the Earth's Radiation Belts: Review of Current Research and Open Questions (2020, background): “These waves were originally referred as magnetosonic equatorial noise (see also Perraut et al., 1982; Santolík et al., 2004; Thomsen et al., 2011).”