Rayleigh-Taylor-Kelvin-Helmholtz combined instability at the magnetopause

Guglielmi, A. V.; Potapov, A. S.; Klain, B. I.

doi:10.1134/s0016793210080050

Cited by 12 publications

(4 citation statements)

References 9 publications

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“…Hence, we interpret the occurrence of vortex-like structures as the result of both the RTI and the KHI. Under this circumstance, the growth rate (the imaginary part of frequency) can be deduced by (Guglielmi et al 2010;Berger et al 2017)…”

Section: Resultsmentioning

confidence: 99%

Flow Instabilities in Solar Jets in Their Upstream and Downstream Regimes

Zhang

Yang

et al. 2019

ApJ

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Using the Atmospheric Imaging Assembly 304Å images obtained from the Solar Dynamics Observatory, we study two jets which occurred during the M5.8 class flare on 2017 April 3 and the M5.5 class flare on 2016 July 23, respectively. During the M5.8 class flare, many vortex-like structures occurred in the upstream and downstream regimes of the associated jet. While the jet was ejected upwards to the corona, some dark material at its base flowed through a bright structure with a velocity of 110 km s −1 . The boundary between the material and the structure changed from smooth to uneven. Later, the jet material at the higher atmosphere started to fall down with velocities of over 200 km s −1 , and the left boundary of the jet developed into a sawtooth pattern. The vortex-like structures were formed, and the growth rates of two structures were presented. During the M5.5 class flare, we also observed many vortex-like structures in the downstream regime of the jet. At the late stage of the jet, some material at the south boundary of the jet fell back to the solar surface, and vortex-like structures at the boundary grew from ripple-like minim into vortices with diameters of 3.4 − 5.4 Mm. The growth rates of the vortex-like structures were calculated. We suggest that the vortex-like structures in the upstream regime are the manifestations of Kelvin−Helmholtz instability, and those in the downstream regime are simultaneously driven by Kelvin−Helmholtz instability and Raleigh−Taylor instability.

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Section: Resultsmentioning

confidence: 99%

Flow Instabilities in Solar Jets in Their Upstream and Downstream Regimes

Zhang

Yang

et al. 2019

ApJ

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“…The combined RTI and KHI of two superimposed magnetized fluids in the presence of suspended dust particles had been investigated by Prajapati et al 4 . Guglielmi et al discussed the coupled RTKHI at the magnetopause 5 , and the possible geophysical applications to the theory (e.g., penetration of the solar plasma into the magnetosphere, excitation of global Pc5 oscillations) were indicated. Ye et al 6,7 investigated analytically the competitions between RTI and KHI in two-dimensional incompressible fluids within a linear growth regime.…”

Section: Introductionmentioning

confidence: 99%

Morphological and non-equilibrium analysis of coupled Rayleigh-Taylor-Kelvin-Helmholtz instability

Chen,

Xu,

Zhang

et al. 2020

Preprint

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In this paper, the coupled Rayleigh-Taylor-Kelvin-Helmholtz instability(RTI, KHI and RTKHI, respectively) system is investigated using a multiple-relaxation-time discrete Boltzmann model. Both the morphological boundary length and thermodynamic nonequilibrium (TNE) strength are introduced to probe the complex configurations and kinetic processes. In the simulations, RTI always plays a major role in the later stage, while the main mechanism in the early stage depends on the comparison of buoyancy and shear strength. It is found that, both the total boundary length L of the condensed temperature field and the mean heat flux strength D 3,1 can be used to measure the ratio of buoyancy to shear strength, and to quantitatively judge the main mechanism in the early stage of the RTKHI system. Specifically, when KHI (RTI) dominates, L

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“…At fluid scales, the RTI can also emerge as a primary instability because of the gravitational acceleration since the magnetosheath is denser than the magnetosphere. However, since the gravitational acceleration is small and because the magnetic field tends to stabilize, the RTI is usually much less considered than the KHI, except than in some special cases (Guglielmi, Potapov & Klain 2010).…”

Section: Introductionmentioning

confidence: 99%

Interplay between Kelvin–Helmholtz and lower-hybrid drift instabilities

et al. 2019

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Boundary layers in space and astrophysical plasmas are the location of complex dynamics where different mechanisms coexist and compete eventually leading to plasma mixing. In this work, we present fully kinetic Particle-In-Cell simulations of different boundary layers characterized by the following main ingredients: a velocity shear, a density gradient and a magnetic gradient localized at the same position. In particular, the presence of a density gradient drives the development of the lower hybrid drift instability (LHDI), which competes with the Kelvin-Helmholtz instability (KHI) in the development of the boundary layer. Depending on the density gradient, the LHDI can even dominate the dynamics of the layer. Because these two instabilities grow on different spatial and temporal scales, when the LHDI develops faster than the KHI an inverse cascade is generated, at least in 2D. This inverse cascade, starting at the LHDI kinetic scales, generates structures at scale lengths at which the KHI would typically develop. When that is the case, those structures can suppress the KHI itself because they significantly affect the underlying velocity shear gradient. We conclude that depending on the density gradient, the velocity jump and the width of the boundary layer, the LHDI in its nonlinear phase can become the primary instability for plasma mixing. These numerical simulations show that the LHDI is likely to be a dominant process at the magnetopause of Mercury. These results are expected to be of direct impact to the interpretation of the forthcoming BepiColombo observations. †

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Rayleigh-Taylor-Kelvin-Helmholtz combined instability at the magnetopause

Cited by 12 publications

References 9 publications

Flow Instabilities in Solar Jets in Their Upstream and Downstream Regimes

Flow Instabilities in Solar Jets in Their Upstream and Downstream Regimes

Morphological and non-equilibrium analysis of coupled Rayleigh-Taylor-Kelvin-Helmholtz instability

Interplay between Kelvin–Helmholtz and lower-hybrid drift instabilities

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