Initial observations of VLF electric and magnetic fields with the Injun 5 satellite

Gurnett, D. A.; Pfeiffer, G. W.; Anderson, R. R.; Mosier, S. R.; Cauffman, David P.

doi:10.1029/ja074i019p04631

Cited by 88 publications

(31 citation statements)

References 30 publications

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“…It has been suggested that EIC heating might represent an initial step of a perpendicular heating process which is completed by the resonant interaction between LH waves and the high energy tail of the ion distribution function (e.g., Chang and Coppi, 1981;Lysak etal., 1980). Several experimenters have observed ion harmonic absorption features in auroral-zone waves near the LH resonance frequency (e.g., Mosier and Gurnett et al, 1969;Ungstrup et al, 1979;Gorney et al, 1981). Gorney et al (1982) have shown that the observed harmonic absorption features can be produced by the tail of the ion conic distribution.…”

Section: Ionospheric Plasma Sourcementioning

confidence: 99%

Auroral plasmas in the evening sector: Satellite observations and theoretical interpretations

et al. 1983

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Observations and theoretical interpretations of auroral plasma distributions have led to a spectacular advance, in the latter part of the 1970's, in understanding the formation of auroral arcs and the role that the aurora plays in the coupling between the magnetosphere and ionosphere in the evening sector.The key to this understanding is the verification of the existence of electric field components parallel to the magnetic field. The parallel electric field accelerates electrons downwards to form the aurora. At the same time, it accelerates ionospheric ions upwards to provide the magnetosphere with a new source of hot plasma. The auroral plasma observations indicate that the hot auroral plasmas behave according to laws of adiabatic motion coexisting with a measure of plasma turbulence. Theoretical considerations of auroral arc formation are in accord with this plasma characteristic.

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Section: Ionospheric Plasma Sourcementioning

confidence: 99%

Auroral plasmas in the evening sector: Satellite observations and theoretical interpretations

et al. 1983

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“…These latter observations will utilize the substantial telemetry capability of Injun 5 to make simultaneous, high-time resolution measurements of electric fields and auroral particle pre- Gurnett et al [1969] for a complete description of the electric field instrumentation on Injun 5-To determine the convection elec--> -» trie field in the plasma the V x B electric field caused by the s spacecraft motion through the ionosphere and small instrumental errors must be subtracted from the measured electric field. Generally the accuracy of the convection electric field determination is limited to approximately +30 mV (m) by errors due to asymmetrical sunlight shadowing of the spheres by the supporting booms.…”

Section: Introductionmentioning

confidence: 99%

Observed relationships between electric fields and auroral particle precipitation

Gurnett

Frank²

1973

J. Geophys. Res.

213

109

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Simultaneous electric field and plasma observations with the low‐altitude polar‐orbiting satellite Injun 5 have provided a comprehensive survey of convection electric fields and their association with magnetospheric plasma phenomena. The most prominent features of the convection electric fields are reversals located at high magnetic latitudes, with generally antisunward convection poleward and sunward convection equatorward of the electric field reversal location. The electric field reversal is interpreted as the boundary between open and closed magnetic field lines. During local day the electric field reversal is observed to coincide with the equatorward boundary of the polar cusp. The plasma flow in the dayside polar cusp region is dominantly E‐W, away from the stagnation point, the convection velocities typically being ∼1 km sec−1. At local evening, ‘inverted V’ electron precipitation bands are observed near or at the position of the electric field reversal. In the local late‐evening sector the electric field reversal becomes less distinct, and often no single well‐defined electric field reversal can be identified. In all cases the inverted V electron precipitation events are closely associated with large, typically >30 mv m−1, irregular electric field fluctuations with time scales of a few seconds or less. Often these fluctuations comprise distinct ‘spikes’ of a few seconds duration or less, which can be identified with distinct boundaries or other features of the electron precipitation. In the local midnight sector, convection electric fields of >50 mv m−1 associated with plasma sheet electrons have been observed extending deep into the magnetosphere, equatorward of the electron (E > 45 kev) trapping boundary. These convection electric fields are characterized by considerably smaller fluctuations relative to those observed within the inverted V electron precipitation bands. To investigate the electric field and plasma interrelationships during a polar magnetic substorm, a series of passes obtained before and during a substorm is presented. Large antisunward convection velocities were detected over the polar cap several tens of minutes before the onset of the expansive phase of the substorm. These convection velocities gradually decreased during the decay phase of the substorm. Our measurements of enhanced antisunward flow over the polar cap region are generally consistent with several current ideas concerning the origin of substorms.

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“…At this frequency the aerial impedance for the ionospheric plasma is practically capacitive (Hugill, 1965;Gurnett et al, 1969). Its value is deter mined by an ion-sheath which developes in the aerial vicinity (Aksenov et al, 1970;Aksenov et #/., 1971).…”

Section: Aerial Capacitance Measurementmentioning

confidence: 99%

First Results of the Soviet-Polish Space Experiment ‘Intercosmos-Kopernik 500’

Hanasz¹,

Aksenov²,

Комраков³

1974

Symp. - Int. Astron. Union

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Abstract. The report contains a short description of the first Soviet-Polish space experiment, which has been accomplished aboard the 'Intercosmos-Kopernik 500' satellite, launched to commemorate the 500 anniversary of Copernicus birth. The purpose of the experiment is to observe sporadic radio emissions generated in the coronal and interplanetary medium at hectometric wave-length range and to measure parameters of the ionospheric plasma by means of the low-and high-frequency impedance probes. The idea of the experiments is presented together with the brief description of the measuring equipment and data recorded. First results of the space observations are shown. The correlation between electron density of the ambient plasma, ion-sheath capacitance of the aerial, and the upper hybrid frequency can be seen.

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Initial observations of VLF electric and magnetic fields with the Injun 5 satellite

Abstract: The Injun 5 satellite, launched into a low altitude

Cited by 88 publications

References 30 publications

Auroral plasmas in the evening sector: Satellite observations and theoretical interpretations

Auroral plasmas in the evening sector: Satellite observations and theoretical interpretations

Observed relationships between electric fields and auroral particle precipitation

First Results of the Soviet-Polish Space Experiment ‘Intercosmos-Kopernik 500’

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