Plasma waves in the dayside polar cusp: 1, Magnetospheric observations

Scarf, F. L.; Fredricks, R. W.; Green, I. M.; Russell, C. T.

doi:10.1029/ja077i013p02274

Cited by 84 publications

(26 citation statements)

References 22 publications

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“…One region where their occurrence is a bit puzzling is in the Earth's polar cusp. They were first observed at high altitudes by the OGO-5 spacecraft (Russell et al, 1971;Scarf et al, 1972;Fredricks and Russell, 1973) and at lower altitudes by Erlandson et al (1988). The range of frequencies is generally between the local proton and alpha particle cyclotron frequency about 4-7 Hz at the location of OGO-5.…”

Section: Ion-cyclotron Waves In the Earth's Polar Cuspmentioning

confidence: 98%

Ion-cyclotron wave generation by planetary ion pickup

Russell

Blanco‐Cano

2007

Journal of Atmospheric and Solar-Terrestrial Physics

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Section: Ion-cyclotron Waves In the Earth's Polar Cuspmentioning

confidence: 98%

Ion-cyclotron wave generation by planetary ion pickup

Russell

Blanco‐Cano

2007

Journal of Atmospheric and Solar-Terrestrial Physics

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“…Possible generation mechanisms include particle beams along the geomagnetic field. There are several reports of EMIC specifically in the cusp (Russel et al, 1971;Scarf et al, 1972;Fredricks and Russell, 1973).…”

Section: Introductionmentioning

confidence: 99%

Multi-spacecraft determination of wave characteristics near the proton gyrofrequency in high-altitude cusp

et al. 2005

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Abstract. We present a detailed study of waves with frequencies near the proton gyrofrequency in the high-altitude cusp for northward IMF as observed by the Cluster spacecraft. Waves in this regime can be important for energization of ions and electrons and for energy transfer between different plasma populations. These waves are present in the entire cusp with the highest amplitudes being associated with localized regions of downward precipitating ions, most probably originating from the reconnection site at the magnetopause. The Poynting flux carried by these waves is downward/upward at frequencies below/above the proton gyrofrequency, which is consistent with the waves being generated near the local proton gyrofrequency in an extended region along the flux tube. We suggest that the waves can be generated by the precipitating ions that show shell-like distributions. There is no clear polarization of the perpendicular wave components with respect to the background magnetic field, while the waves are polarized in a parallelperpendicular plane. The coherence length is of the order of one ion-gyroradius in the direction perpendicular to the ambient magnetic field and a few times larger or more in the parallel direction. The perpendicular phase velocity was found to be of the order of 100 km/s, an order of magnitude lower than the local Alfvén speed. The perpendicular wavelength is of the order of a few proton gyroradius or less. Based on our multi-spacecraft observations we conclude that the waves cannot be ion-whistlers, while we suggest that the waves can belong to the kinetic Alfvén branch below the proton gyrofrequency f cp and be described as non-potential ion-cyclotron waves (electromagnetic ion-Bernstein waves) above. LinearCorrespondence to: D. Sundkvist (davids@irfu.se) wave growth calculations using kinetic code show considerable wave growth of non-potential ion cyclotron waves at wavelengths agreeing with observations. Inhomogeneities in the plasma on the order of the ion-gyroradius suggests that inhomogeneous (drift) or nonlinear effects or both of these should be taken into account.

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“…Electrostatic emissions at (n+1/2)Qe with n=1, 2, and 3 have been observed in the high-altitude magnetospheric on OGO-5 (KENNEL et al, 1970;SCARF et al, 1972).…”

Section: Instabilities In the Lower Ionosphere Driven By Perpendiculamentioning

confidence: 99%

A review of electrostatic wave measurements on auroral magnetic field lines.

Kelley

1978

J. geomagn. geoelec

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This review emphasizes experimental evidence for electrostatic waves on auroral zone magnetic field lines. Data were obtained from radar, balloon, rocket, and satellite observations. The paper is organized around three topics: (1) the turbulent density and velocity fields of the magnetospheric flow, (2) instabilities associated with the convection electric field and its interactions with the neutral atmosphere, and (3) waves and discontinuities in the dynamic region at about one Earth radius above the auroral zone. Measurements of both the electric field and density fluctuation component of such waves will be included. Although this is not a theoretical study, an attempt is made to organize the measurements about the existing theoretical framework.

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Plasma waves in the dayside polar cusp: 1, Magnetospheric observations

Cited by 84 publications

References 22 publications

Ion-cyclotron wave generation by planetary ion pickup

Ion-cyclotron wave generation by planetary ion pickup

Multi-spacecraft determination of wave characteristics near the proton gyrofrequency in high-altitude cusp

A review of electrostatic wave measurements on auroral magnetic field lines.

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