New type of soliton in Bi‐ion plasmas and possible implications

Sauer, K.; Dubinin, E.; McKenzie, J. F.

doi:10.1029/2001gl013047

Cited by 69 publications

(86 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A significant feature of this mode is the appearance of a phase velocity maximum at finite wave numbers (kc/ω e < 1), which results from the different (phase velocity-wave number) dependence of both merging modes, and the associated gap above it. As known from previous studies of nonlinear stationary structures on other wave branches (multi-ion waves, whistler waves in plasmas with G < 1 and lowerhybrid waves; see Sauer et al, 2001;Dubinin et al, 2003;Ma and Hirose, 2010), such mode characteristics are favorable for the existence of oscillitons. For obvious reasons, we use the term whistler-Langmuir oscilliton to describe the mixed mode nonlinear stationary wave structure considered in this work.…”

Section: Dispersion Relationmentioning

confidence: 93%

“…Since their first description in multi-ion plasmas (Sauer et al, 2001 and for the whistler wave branch Dubinin et al, 2003), there is a continuous effort to find out whether they are of similar physical relevance as the classical solitons in nonlinear media. Of particular interest is the question regarding their role in explaining the origin of waves measured in space.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Whistler-Langmuir oscillitons and their relation to auroral hiss

Sauer

Sydora

2011

Ann. Geophys.

Self Cite

View full text Add to dashboard Cite

Abstract.A new type of oscilliton (soliton with superimposed spatial oscillations) is described which arises in plasmas if the electron cyclotron frequency e is larger than the electron plasma frequency ω e , which is a typical situation for auroral regions in planetary magnetospheres. Both highfrequency modes of concern, the Langmuir and the whistler wave, are completely decoupled if they propagate parallel to the magnetic field. However, for oblique propagation two mixed modes are created with longitudinal and transverse electric field components. The lower mode (in the literature commonly called the whistler mode, e.g. Gurnett et al., 1983) has whistler wave characteristics at small wave numbers and asymptotically transforms into the Langmuir mode. As a consequence of the coupling between these two modes, with different phase velocity dependence, a maximum in phase velocity appears at finite wave number. The occurrence of such a particular point where phase and group velocity coincide creates the condition for the existence of a new type of oscillating nonlinear stationary structure, which we call the whistler-Langmuir (WL) oscilliton. After determining, by means of stationary dispersion theory, the parameter regime in which WL oscillitons exist, their spatial profiles are calculated within the framework of cold (non-relativistic) fluid theory. Particle-in-cell (PIC) simulations are used to demonstrate the formation of WL oscillitons which seem to play an important role in understanding electron beam-excited plasma radiation that is observed as auroral hiss in planetary magnetospheres far away from the source region.

show abstract

Section: Dispersion Relationmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Whistler-Langmuir oscillitons and their relation to auroral hiss

Sauer

Sydora

2011

Ann. Geophys.

Self Cite

View full text Add to dashboard Cite

show abstract

“…To get the phase velocity of the quasi-stationary wave solutions, i.e., solitons and oscillitons, we need to solve equation (B21) for k as a function of the phase velocity V ph ¼ ω k [Sauer et al, 2001Dubinin et al, 2006]. Substituting the phase velocity into equation (B21), we can rewrite the linear dispersion relation as…”

Section: 1002/2015ja021437mentioning

confidence: 99%

“…There is a gap in phase velocity, where linear waves cannot propagate. This is where quasi-stationary nonlinear wave solutions, solitons, and oscillitons exist [Sauer et al, 2001Dubinin et al, 2006]. A soliton is a large-amplitude solitary structure that appears as a single peak or depression in the magnetic field and plasma parameters.…”

Section: Introductionmentioning

confidence: 99%

“…A soliton is a large-amplitude solitary structure that appears as a single peak or depression in the magnetic field and plasma parameters. An oscilliton, on the other hand, is a largeamplitude periodic structure that appears as a quasi-stationary wave train [Sauer et al, 2001]. In order to get the phase velocity of quasi-stationary wave solutions, we need to solve the three-fluid plasma dispersion relation D(ω, k) = 0 (equation (B21)) for k as a function of the phase velocity, V ph ¼ ω k .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Constraining the pickup ion abundance and temperature through the multifluid reconstruction of the Voyager 2 termination shock crossing

et al. 2015

View full text Add to dashboard Cite

Voyager 2 observations revealed that the hot solar wind ions (the so‐called pickup ions) play a dominant role in the thermodynamics of the termination shock and the heliosheath. The number density and temperature of this hot population, however, have remained unknown, since the plasma instrument on board Voyager 2 can only detect the colder thermal ion component. Here we show that due to the multifluid nature of the plasma, the fast magnetosonic mode splits into a low‐frequency fast mode and a high‐frequency fast mode. The coupling between the two fast modes results in a quasi‐stationary nonlinear wave mode, the “oscilliton,” which creates a large‐amplitude trailing wave train downstream of the thermal ion shock. By fitting multifluid shock wave solutions to the shock structure observed by Voyager 2, we are able to constrain both the abundance and the temperature of the undetected pickup ions. In our three‐fluid model, we take into account the nonnegligible partial pressure of suprathermal energetic electrons (0.022–1.5 MeV) observed by the Low‐Energy Charged Particle Experiment instrument on board Voyager 2. The best fitting simulation suggests a pickup ion abundance of 20 ± 3%, an upstream pickup ion temperature of 13.4 ± 2 MK, and a hot electron population with an apparent temperature of ~0.83 MK. We conclude that the actual shock transition is a subcritical dispersive shock wave with low Mach number and high plasma β.

show abstract

Proton cyclotron waves occurrence rate upstream from Mars observed by MAVEN: Associated variability of the Martian upper atmosphere

et al. 2016

View full text Add to dashboard Cite

Measurements provided by the Magnetometer and the Extreme Ultraviolet Monitor (EUVM) on board the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft together with atomic H exospheric densities derived from numerical simulations are studied for the time interval from October 2014 up to March 2016. We determine the proton cyclotron waves (PCWs) occurrence rate observed upstream from Mars at different times. We also study the relationship with temporal variabilities of the high‐altitude Martian hydrogen exosphere and the solar EUV flux reaching the Martian environment. We find that the abundance of PCWs is higher when Mars is close to perihelion and decreases to lower and approximately constant values after the Martian Northern Spring Equinox. We also conclude that these variabilities cannot be associated with biases in MAVEN's spatial coverage or changes in the background magnetic field orientation. Higher H exospheric densities on the Martian dayside are also found when Mars is closer to perihelion, as a result of changes in the thermospheric response to variability in the ultraviolet flux reaching Mars at different orbital distances. A consistent behavior is also observed in the analyzed daily irradiances measured by the MAVEN EUVM. The latter trends point toward an increase in the planetary proton densities upstream from the Martian bow shock near perihelion. These results then suggest a method to indirectly monitor the variability of the H exosphere up to very high altitudes during large time intervals (compared to direct measurements of neutral particles), based on the observed abundance of PCWs.

show abstract

New type of soliton in Bi‐ion plasmas and possible implications

Cited by 69 publications

References 15 publications

Whistler-Langmuir oscillitons and their relation to auroral hiss

Whistler-Langmuir oscillitons and their relation to auroral hiss

Constraining the pickup ion abundance and temperature through the multifluid reconstruction of the Voyager 2 termination shock crossing

Proton cyclotron waves occurrence rate upstream from Mars observed by MAVEN: Associated variability of the Martian upper atmosphere

Contact Info

Product

Resources

About