Three‐dimensional structure of electron holes driven by an electron beam

Singh, Nagendra; Loo, Sin Ming; Wells, B. Earl; Deverapalli, C.

doi:10.1029/2000gl003766

Cited by 38 publications

(49 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We note that these types of electron populations are observed in this region even in the absence of solitary waves. The usually favored mechanism for creating the solitary waves are the electron beam instabilities similar to those proposed to be the generation mechanism for the solitary waves observed in the deep magnetotail and auroral zone (Omura et al, 1996;Goldman et al, 1999;Singh et al, 2000;Newman et al, 2001;Javanovic et al, 2002). However, these electron beams are not always present at the exact times when the solitary waves are observed on Cluster, perhaps because the time resolution of the Cluster PEACE instrument is not sufficient when compared to solitary waves that occur on time scales on the order of 1 ms. Further, the PEACE angular resolution is not narrow enough to determine whether the beams that are occasionally observed simultaneously with the solitary waves are actually beams, or whether they are unresolved conics.…”

Section: Discussionmentioning

confidence: 99%

“…Thus, it is unlikely that the solitary waves observed by Cluster were generated in the auroral acceleration region. However, if the solitary waves were generated just several tens to a few hundreds of km below (or above) the Cluster spacecraft, the Singh et al (2000) simulation results provide some insight into their possible evolution. Unipolar and bipolar pulses emerge from the high frequency waves within 120 plasma periods (approximately 42 ms at a density of 0.1 cm −3 ).…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Solitary waves observed in the auroral zone: the Cluster multi-spacecraft perspective

Pickett

Kahler

Chen

et al. 2004

Nonlin. Processes Geophys.

View full text Add to dashboard Cite

Abstract. We report on recent measurements of solitary waves made by the Wideband Plasma Wave Receiver located on each of the four Cluster spacecraft at 4.5-6.5 R E (well above the auroral acceleration region) as they cross field lines that map to the auroral zones. These solitary waves are observed in the Wideband data as isolated bipolar and tripolar waveforms. Examples of the two types of pulses are provided. The time durations of the majority of both types of solitary waves observed in this region range from about 0.3 up to 5 ms. Their peak-to-peak amplitudes range from about 0.05 up to 20 mV/m, with a few reaching up to almost 70 mV/m. There is essentially no potential change across the bipolar pulses. There appears to be a small, measurable potential change, up to 0.5 V, across the tripolar pulses, which is consistent with weak or hybrid double layers. A limited cross-spacecraft correlation study was carried out in order to identify the same solitary wave on more than one spacecraft. We found no convincing correlations of the bipolar solitary waves. In the two cases of possible correlation of the tripolar pulses, we found that the solitary waves are propagating at several hundred to a few thousand km/s and that they are possibly evolving (growing, decaying) as they propagate from one spacecraft to the next. Further, they have a perpendicular (to the magnetic field) width of 50 km or greater and a parallel width of about 2-5 km. We conclude, in general, Correspondence to: J. S. Pickett (pickett@uiowa.edu) however, that the Cluster spacecraft at separations along and perpendicular to the local magnetic field direction of tens of km and greater are too large to obtain positive correlations in this region. Looking at the macroscale of the auroral zone at 4.5-6.5 R E , we find that the onsets of the broadband electrostatic noise associated with the solitary waves observed in the spectrograms of the WBD data are generally consistent with propagation of the solitary waves up the field lines (away from Earth), or with particles or waves propagating up the field line, which leads to local generation of the solitary waves all along the field lines. A discussion of the importance of these solitary waves in magnetospheric processes and their possible generation mechanisms, through electron beam instabilities and turbulence, is provided.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Solitary waves observed in the auroral zone: the Cluster multi-spacecraft perspective

Pickett

Kahler

Chen

et al. 2004

Nonlin. Processes Geophys.

View full text Add to dashboard Cite

show abstract

“…Note, ESWs can either couple to, or directly cause, the growth of IAWs [e.g., Dyrud and Oppenheim, 2006], whistler mode waves [e.g., Goldman et al, 2014;Lu et al, 2008;Singh et al, 2001], or lower hybrid waves [e.g., Singh et al, 2000]. The large magnetic fluctuations, due to magnetosonic-whistler waves, can produce strong localized currents and compress the plasma producing a temperature anisotropy.…”

Section: Wave Propertiesmentioning

confidence: 99%

Quantified energy dissipation rates in the terrestrial bow shock: 2. Waves and dissipation

et al. 2014

View full text Add to dashboard Cite

Key Points:• Microscopic wave-particle interactions can regulate macroscopic shock structure • High-frequency large-amplitude waves are ubiquitous in collisionless shocks • Wave-particle interactions are the end result of nearly all dissipation pathways AbstractWe present the first quantified measure of the energy dissipation rates, due to wave-particle interactions, in the transition region of the Earth's collisionless bow shock using data from the Time History of Events and Macroscale Interactions during Substorms spacecraft. Our results show that wave-particle interactions can regulate the global structure and dominate the energy dissipation of collisionless shocks. In every bow shock crossing examined, we observed both low-frequency (<10 Hz) and high-frequency (≳10 Hz) electromagnetic waves throughout the entire transition region and into the magnetosheath. The low-frequency waves were consistent with magnetosonic-whistler waves. The high-frequency waves were combinations of ion-acoustic waves, electron cyclotron drift instability driven waves, electrostatic solitary waves, and whistler mode waves. The high-frequency waves had the following: (1) peak amplitudes exceeding B ∼ 10 nT and E ∼ 300 mV/m, though more typical values were B ∼ 0.1-1.0 nT and E ∼ 10-50 mV/m; (2) Poynting fluxes in excess of 2000 μW m −2 (typical values were ∼ 1-10 μW m −2 ); (3) resistivities > 9000 Ω m; and (4) associated energy dissipation rates > 10 μW m −3 . The dissipation rates due to wave-particle interactions exceeded rates necessary to explain the increase in entropy across the shock ramps for ∼90% of the wave burst durations. For ∼22% of these times, the wave-particle interactions needed to only be ≤ 0.1% efficient to balance the nonlinear wave steepening that produced the shock waves. These results show that wave-particle interactions have the capacity to regulate the global structure and dominate the energy dissipation of collisionless shocks.

show abstract

“…There have been numerous reports of observations of isolated electrostatic structures (IES), also referred to as solitary waves and electrostatic solitary waves, and their onsets in the dynamical regions of the Earth's magnetosphere (Franz et al, 1998;Kojima et al, 1999;Franz, 2000;Cattell et al, 2003;Lakhina et al, 2003;and references therein), as well as of theoretical (Schamel, 1986;Muschietti et al, 1999a,b;Chen and Parks, 2002a,b; and simulation (Omura et al, 1996;Oppenheim et al, 1999;Muschietti et al, 2000;Singh, 2000;Singh et al, 2000) studies of IES. However, no observational studies on how bipolar IES characteristics depend on the local magnetic field strength have been carried out, and there have been no systematic studies on tripolar IES.…”

Section: Introductionmentioning

confidence: 99%

Isolated electrostatic structures observed throughout the Cluster orbit: relationship to magnetic field strength

et al. 2004

View full text Add to dashboard Cite

Abstract. Isolated electrostatic structures are observed throughout much of the 4 R E by 19.6 R E Cluster orbit. These structures are observed in the Wideband plasma wave instrument's waveform data as bipolar pulses (one positive and one negative peak in the electric field amplitude) and tripolar pulses (two positive and one negative peak, or vice versa). These structures are observed at all of the boundary layers, in the solar wind and magnetosheath, and along auroral field lines at 4.5-6.5 R E . Using the Wideband waveform data from the various Cluster spacecraft we have carried out a survey of the amplitudes and time durations of these structures and how these quantities vary with the local magnetic field strength. Such a survey has not been carried out before, and it reveals certain characteristics of solitary structures in a finite magnetic field, a topic still inadequately addressed by theories. We find that there is a broad range of electric field amplitudes at any specific magnetic field strength, and there is a general trend for the electric field amplitudes to increase as the strength of the magnetic field increases over a range of 5 to 500 nT. We provide a possible explanation for this trend that relates to the structures being Bernstein-GreeneKruskal mode solitary waves. There is no corresponding dependence of the duration of the structures on the magnetic field strength, although a plot of these two quantities reveals the unexpected result that with the exception of the magnetosheath, all of the time durations for all of the other regions are comparable, whereas the magnetosheath time durations clearly are in a different category of much smaller time duration. We speculate that this implies that the structures are much smaller in size. The distinctly different pulse durations for the magnetosheath pulses indicate the possibility that the pulses are generated by a mechanism which is different from the mechanism operating in other regions.

show abstract

Three‐dimensional structure of electron holes driven by an electron beam

Cited by 38 publications

References 17 publications

Solitary waves observed in the auroral zone: the Cluster multi-spacecraft perspective

Solitary waves observed in the auroral zone: the Cluster multi-spacecraft perspective

Quantified energy dissipation rates in the terrestrial bow shock: 2. Waves and dissipation

Isolated electrostatic structures observed throughout the Cluster orbit: relationship to magnetic field strength

Contact Info

Product

Resources

About