Observations of whistler mode waves by Solar Orbiter's RPW Low Frequency Receiver (LFR): In-flight performance and first results

<p>Frequency-latitude plots of electromagnetic wave intensity in the very low frequency range (VLF, up to about 20 kHz) observed by the low altitude DEMETER spacecraft are analyzed. Apart from electromagnetic waves generated by plasma instabilities in the magnetosphere, a significant portion of the detected wave intensity comes from ground-based lightning activity and VLF military transmitters. These whistler mode waves are observed not only close to source locations, but also close to their geomagnetically conjugated points. There appears to be an upper frequency limit of such emissions, where the wave intensity substantially decreases. Its frequency roughly corresponds to half of the equatorial electron cyclotron frequency at a respective magnetic field line, suggesting a relation to wave ducting in ducts with enhanced density. However, it seems to exhibit a non-negligible longitudinal dependence and it is different during the day than during the night. We use a realistic model of the Earth&#8217;s magnetic field to explain the observed variations. We interpret the observations in terms of ducted/unducted wave propagation, and we compare the wave intensities in the source hemisphere with those measured in the hemisphere geomagnetically conjugated.</p>

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Extremely intense whistler mode waves near the bow shock: Geotail observations

Journal of Geophysical Research Atmospheres ◽

10.1029/1998ja900049-a ◽

1999 ◽

Vol 104 (A1) ◽

pp. 449-462 ◽

Cited By ~ 3

Author(s):

Y. Zhang

Keyword(s):

Bow Shock ◽

Whistler Mode ◽

Whistler Mode Waves

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Discrete rising tone elements of whistler‐mode waves in the vicinity of the Moon: ARTEMIS observations

Geophysical Research Letters ◽

10.1029/2020gl091100 ◽

2020 ◽

Author(s):

W. Sawaguchi ◽

Y. Harada ◽

S. Kurita

Keyword(s):

The Moon ◽

Whistler Mode ◽

Whistler Mode Waves

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First results of low frequency electromagnetic wave detector of TC-2/Double Star program

Annales Geophysicae ◽

10.5194/angeo-23-2803-2005 ◽

2005 ◽

Vol 23 (8) ◽

pp. 2803-2811 ◽

Cited By ~ 29

Author(s):

J. B. Cao ◽

Z. X. Liu ◽

J. Y. Yang ◽

C. X. Yian ◽

Z. G. Wang ◽

...

Keyword(s):

Electromagnetic Wave ◽

Southern Hemisphere ◽

Northern Hemisphere ◽

Geomagnetic Storms ◽

Low Frequency ◽

Wave Detector ◽

Ion Cyclotron Waves ◽

Satellite Platform ◽

Ion Cyclotron ◽

First Results

Abstract. LFEW is a low frequency electromagnetic wave detector mounted on TC-2, which can measure the magnetic fluctuation of low frequency electromagnetic waves. The frequency range is 8 Hz to 10 kHz. LFEW comprises a boom-mounted, three-axis search coil magnetometer, a preamplifier and an electronics box that houses a Digital Spectrum Analyzer. LFEW was calibrated at Chambon-la-Forêt in France. The ground calibration results show that the performance of LFEW is similar to that of STAFF on TC-1. The first results of LFEW show that it works normally on board, and that the AC magnetic interference of the satellite platform is very small. In the plasmasphere, LFEW observed the ion cyclotron waves. During the geomagnetic storm on 8 November 2004, LFEW observed a wave burst associated with the oxygen ion cyclotron waves. This observation shows that during geomagnetic storms, the oxygen ions are very active in the inner magnetosphere. Outside the plasmasphere, LFEW observed the chorus on 3 November 2004. LFEW also observed the plasmaspheric hiss and mid-latitude hiss both in the Southern Hemisphere and Northern Hemisphere on 8 November 2004. The hiss in the Southern Hemisphere may be the reflected waves of the hiss in the Northern Hemisphere.

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Radial variation of whistler-mode chorus: first results from the STAFF/DWP instrument on board the Double Star TC-1 spacecraft

Annales Geophysicae ◽

10.5194/angeo-23-2937-2005 ◽

2005 ◽

Vol 23 (8) ◽

pp. 2937-2942 ◽

Cited By ~ 45

Author(s):

O. Santolík ◽

E. Macúšová ◽

K. H. Yearby ◽

N. Cornilleau-Wehrlin ◽

H. StC. K. Alleyne

Keyword(s):

Cyclotron Frequency ◽

Power Spectra ◽

Double Star ◽

Electron Cyclotron ◽

Radial Variation ◽

Whistler Mode ◽

Electron Cyclotron Frequency ◽

The Earth ◽

First Results ◽

Initial Results

Abstract. We use the first measurements of the STAFF/DWP instrument on the Double Star TC-1 spacecraft to investigate whistler-mode chorus. We present initial results of a systematic study on radial variation of dawn chorus. The chorus events show an increased intensity at L parameter above 6. This is important for the possible explanation of intensifications of chorus, which were previously observed closer to the Earth at higher latitudes. Our results also indicate that the upper band of chorus at frequencies above one-half of the electron cyclotron frequency disappears for L above 8. The lower band of chorus is observed at frequencies below 0.4 of the electron cyclotron frequency up to L of 11-12. The maxima of the chorus power spectra are found at slightly lower frequencies compared to previous studies. We do not observe any distinct evolution of the position of the chorus frequency band as a function of L. More data of the TC-1 spacecraft are needed to verify these initial results and to increase the MLT coverage.

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