Satellite observations of Pc 1 pearl waves: The changing paradigm

Мурсула, К.

doi:10.1016/j.jastp.2007.02.013

Cited by 41 publications

(43 citation statements)

References 42 publications

(51 reference statements)

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“…However, new precise observations by satellites indicate that the repetition periods of pearl events are shorter than those expected from the BWP model [e.g., Mursula et al, 1997; Usanova et al, 2008], and that only 10%-20% of the incident wave energy is reflected from the ionosphere [Erlandson et al, 1992]. Plyasova-Bakounina et al [1996] and Mursula [2007] attempted to explain the pearl structures as a modulation of EMIC waves by coexisting Pc4-5 waves. For the event of 5 November 2007, pearl structures with repetition periods of ∼5-30 s were seen at MSR, as shown in Figures 6 and 7.…”

Section: Pearl Structuresmentioning

confidence: 99%

Frequency-dependent polarization characteristics of Pc1 geomagnetic pulsations observed by multipoint ground stations at low latitudes

et al. 2011

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Section: Pearl Structuresmentioning

confidence: 99%

Frequency-dependent polarization characteristics of Pc1 geomagnetic pulsations observed by multipoint ground stations at low latitudes

et al. 2011

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“…However, fine-structured Pc1 waves are rarely observed by satellites [e.g., Erlandson et al, 1992;Mursula, 2007]. A spacecraft observation has recently revealed EMIC waves with fine structures which consist of coherent rising tones similar to whistler mode chorus emissions .…”

Section: Introductionmentioning

confidence: 99%

Subpacket structures in EMIC rising tone emissions observed by the THEMIS probes

Nakamura

Omura

Motomizu³

et al. 2015

JGR Space Physics

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We report subpacket structures found in electromagnetic ion cyclotron (EMIC) rising tone emissions observed by the Time History of Events and Macroscale Interactions during Substorms (THEMIS) probes. We investigate three typical cases in detail. The first case shows a continuous single rising tone with four obvious subpackets, and the second case is characterized by a patchy emission with multiple subpackets triggered in a broadband frequency. The third case looks like a smooth rising tone without any obvious subpacket in the fast Fourier transform spectrum, while its amplitude contains small peaks with increasing frequencies. The degree of polarization of each subpacket is generally higher than 0.8 with a left-handed polarization, and the wave direction of the subpackets is typically field aligned. We show that the time evolution of the observed frequency and amplitude can be reproduced consistently by nonlinear growth theory. We also compare the observed time span of each subpacket structure with the theoretical trapping time for second-order cyclotron resonance. They are consistent, indicating that an individual subpacket is generated through a nonlinear wave growth process which excites an element in accordance with the theoretically predicted optimum amplitude.

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“…The Pc1 occurrence rate in that paper was higher for storm recovery phase than during other phases of storms. For further details on Pc1 pulsations readers are referred to the reviews by Guglielmi and Pokhotelov (1996), Kangas et al (1998) or Mursula (2007.…”

Section: Introductionmentioning

confidence: 99%

Global characteristics of Pc1 magnetic pulsations during solar cycle 23 deduced from CHAMP data

2013

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We present a global climatology of Pc1 pulsations as observed by the CHAMP satellite from 2000 to 2010. The Pc1 center frequency and bandwidth are about 1 and 0.5 Hz, respectively. The ellipticity is mostly linear with the major axis almost aligned with the magnetic zonal direction. The diurnal variation of Pc1 occurrences shows a primary maximum early in the morning and a secondary maximum during pre-midnight hours. The annual variations of the occurrence rates exhibit a clear preference for local summer. The solar cycle dependence of the occurrence rate reveals a maximum at the declining phase (2004–2005). Neither magnetic activity nor solar wind velocity controls the Pc1 occurrence rate significantly. Pc1 occurrence rate peaks at subauroral latitudes, but the steep cutoff towards higher latitudes is due to auroral field-aligned currents masking the Pc1 pulsations. The center frequency of Pc1 pulsations does not show a clear dependence on latitude. The global distribution of Pc1 exhibits highest occurrence rates near the longitude sector of the South Atlantic Anomaly. Pc1 events at auroral latitudes, although they are rarely detected, show a clear occurrence peak around local noon. A majority of the auroral Pc1 events are observed during solar minimum years

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Satellite observations of Pc 1 pearl waves: The changing paradigm

Cited by 41 publications

References 42 publications

Frequency-dependent polarization characteristics of Pc1 geomagnetic pulsations observed by multipoint ground stations at low latitudes

Frequency-dependent polarization characteristics of Pc1 geomagnetic pulsations observed by multipoint ground stations at low latitudes

Subpacket structures in EMIC rising tone emissions observed by the THEMIS probes

Global characteristics of Pc1 magnetic pulsations during solar cycle 23 deduced from CHAMP data

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