A new MHD model for Io's and Europa's plasma interaction

<p>Io and Europa are embedded in Jupiter&#8217;s magnetosphere and the moons&#8217; surfaces and atmospheres interact with the surrounding moving magnetized plasma forming a complex plasma&#160;interaction. The interaction scenarios for both moons are characterized by inhomogeneities in the atmospheres from local outgassing. These inhomogeneities affect the electromagnetic&#160;environment but can also lead to localized features in the moons' auroral emissions. The moons&#8217; aurora in turn is sensitive to the energy or temperature of the exciting electrons in the plasma. To simulate the&#160;interaction scenarios including atmospheric inhomogeneities and aurora generation, we expand the magnetohydrodynamic code MPI-AMRVAC by implementing a self-consistent description of&#160;the electron temperature and the electron density where the cooling by inelastic collisions between the magnetospheric electrons and the atmosphere, and the electron heat flux from the&#160;magnetospheric plasma to the moons&#8217; ionosphere are included. Furthermore, the numerical schemes of MPI-AMRVAC are able to handle discontinuities that arise from the atmospheric inhomogeneities. Here,&#160;we demonstrate the&#160;implementation of the physical effects and first modeling results of Io&#8217;s and Europa&#8217;s plasma interaction with the advanced MHD code.</p>

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Self‐consistent, nonlocal electron heat flux at arbitrary ion charge number

Physics of Fluids B Plasma Physics ◽

10.1063/1.860366 ◽

1992 ◽

Vol 4 (11) ◽

pp. 3579-3585 ◽

Cited By ~ 10

Author(s):

Juan R. Sanmartín ◽

J. Ramírez ◽

R. Fernández‐Feria ◽

F. Minotti

Keyword(s):

Heat Flux ◽

Charge Number ◽

Electron Heat ◽

Self Consistent

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The role of electron heat flux in guide-field magnetic reconnection

Physics of Plasmas ◽

10.1063/1.1795991 ◽

2004 ◽

Vol 11 (12) ◽

pp. 5387-5397 ◽

Cited By ~ 70

Author(s):

Michael Hesse ◽

Masha Kuznetsova ◽

Joachim Birn

Keyword(s):

Heat Flux ◽

Magnetic Reconnection ◽

Guide Field ◽

Electron Heat

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Comparison of the measured and modelled electron densities and temperatures in the ionosphere and plasmasphere during 20-30 January, 1993

Annales Geophysicae ◽

10.1007/s00585-000-1257-6 ◽

2000 ◽

Vol 18 (10) ◽

pp. 1257-1262 ◽

Cited By ~ 1

Author(s):

A. V. Pavlov ◽

T. Abe ◽

K.-I. Oyama

Keyword(s):

Magnetic Field ◽

Heat Flux ◽

Electron Temperature ◽

Field Line ◽

Electron Density ◽

Magnetic Field Line ◽

New Approach ◽

Additional Heating ◽

Vibrational Levels ◽

The Magnetic Field

Abstract. We present a comparison of the electron density and temperature behaviour in the ionosphere and plasmasphere measured by the Millstone Hill incoherent-scatter radar and the instruments on board of the EXOS-D satellite with numerical model calculations from a time-dependent mathematical model of the Earth's ionosphere and plasmasphere during the geomagnetically quiet and storm period on 20–30 January, 1993. We have evaluated the value of the additional heating rate that should be added to the normal photoelectron heating in the electron energy equation in the daytime plasmasphere region above 5000 km along the magnetic field line to explain the high electron temperature measured by the instruments on board of the EXOS-D satellite within the Millstone Hill magnetic field flux tube in the Northern Hemisphere. The additional heating brings the measured and modelled electron temperatures into agreement in the plasmasphere and into very large disagreement in the ionosphere if the classical electron heat flux along magnetic field line is used in the model. A new approach, based on a new effective electron thermal conductivity coefficient along the magnetic field line, is presented to model the electron temperature in the ionosphere and plasmasphere. This new approach leads to a heat flux which is less than that given by the classical Spitzer-Harm theory. The evaluated additional heating of electrons in the plasmasphere and the decrease of the thermal conductivity in the topside ionosphere and the greater part of the plasmasphere found for the first time here allow the model to accurately reproduce the electron temperatures observed by the instruments on board the EXOS-D satellite in the plasmasphere and the Millstone Hill incoherent-scatter radar in the ionosphere. The effects of the daytime additional plasmaspheric heating of electrons on the electron temperature and density are small at the F-region altitudes if the modified electron heat flux is used. The deviations from the Boltzmann distribution for the first five vibrational levels of N2(v) and O2(v) were calculated. The present study suggests that these deviations are not significant at the first vibrational levels of N2 and O2 and the second level of O2, and the calculated distributions of N2(v) and O2(v) are highly non-Boltzmann at vibrational levels v > 2. The resulting effect of N2(v > 0) and O2(v > 0) on NmF2 is the decrease of the calculated daytime NmF2 up to a factor of 1.5. The modelled electron temperature is very sensitive to the electron density, and this decrease in electron density results in the increase of the calculated daytime electron temperature up to about 580 K at the F2 peak altitude giving closer agreement between the measured and modelled electron temperatures. Both the daytime and night-time densities are not reproduced by the model without N2(v > 0) and O2(v > 0), and inclusion of vibrationally excited N2 and O2 brings the model and data into better agreement.Key words: Ionosphere (ionospheric disturbances; ionosphere-magnetosphere interactions; plasma temperature and density)

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The electron heat flux in the polar solar wind: Ulysses observations

Geophysical Research Letters ◽

10.1029/1999gl900503 ◽

1999 ◽

Vol 26 (14) ◽

pp. 2129-2132 ◽

Cited By ~ 10

Author(s):

Earl E. Scime ◽

Allen E. Badeau ◽

J. E. Littleton

Keyword(s):

Heat Flux ◽

Solar Wind ◽

Electron Heat

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Controlled photo-discharge of dust in a complex plasma

Journal of Plasma Physics ◽

10.1017/s002237782100043x ◽

2021 ◽

Vol 87 (2) ◽

Author(s):

Michael McKinlay ◽

Edward Thomas

Keyword(s):

High Intensity ◽

Dusty Plasmas ◽

Lanthanum Hexaboride ◽

Magnetized Plasma ◽

Background Plasma ◽

Proof Of Concept ◽

Langmuir Probes ◽

Complex Plasma ◽

Dust Charge ◽

Selection Of

One of the limitations in studying dusty plasmas is that many of the important properties of the dust (like the charge) are directly coupled to the surrounding plasma conditions rather than being determined independently. The application of high-intensity ultraviolet (UV) sources to generate discharging photoelectric currents may provide an avenue for developing methods of controlling dust charge. Careful selection of the parameters of the UV source and dust material may even allow for this to be accomplished with minimal perturbation of the background plasma. The Auburn Magnetized Plasma Research Laboratory (MPRL) has developed a ‘proof-of-concept’ experiment for this controlled photo-discharging of dust; a high-intensity, near-UV source was used to produce large changes in the equilibrium positions of lanthanum hexaboride ( $\textrm {LaB}_6$ ) particles suspended in an argon DC glow discharge with negligible changes in the potential, density and temperature profiles of the background plasma. The shifts in equilibrium position of the dust are consistent with a reduction in dust charge. Video analysis is used to quantify the changes in position, velocity and acceleration of a test particle under the influence of the UV and Langmuir probes are used to measure the effects on the plasma.

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An explicit algebraic Reynolds-stress and scalar-flux model for stably stratified flows

Journal of Fluid Mechanics ◽

10.1017/jfm.2013.116 ◽

2013 ◽

Vol 723 ◽

pp. 91-125 ◽

Cited By ~ 21

Author(s):

W. M. J. Lazeroms ◽

G. Brethouwer ◽

S. Wallin ◽

A. V. Johansson

Keyword(s):

Heat Flux ◽

Kinetic Energy ◽

Temperature Gradient ◽

Reynolds Stress ◽

Turbulent Heat Flux ◽

Turbulent Heat ◽

Homogeneous Shear ◽

Self Consistent ◽

The Mean ◽

Homogeneous Shear Flow

AbstractThis work describes the derivation of an algebraic model for the Reynolds stresses and turbulent heat flux in stably stratified turbulent flows, which are mutually coupled for this type of flow. For general two-dimensional mean flows, we present a correct way of expressing the Reynolds-stress anisotropy and the (normalized) turbulent heat flux as tensorial combinations of the mean strain rate, the mean rotation rate, the mean temperature gradient and gravity. A system of linear equations is derived for the coefficients in these expansions, which can easily be solved with computer algebra software for a specific choice of the model constants. The general model is simplified in the case of parallel mean shear flows where the temperature gradient is aligned with gravity. For this case, fully explicit and coupled expressions for the Reynolds-stress tensor and heat-flux vector are given. A self-consistent derivation of this model would, however, require finding a root of a polynomial equation of sixth-order, for which no simple analytical expression exists. Therefore, the nonlinear part of the algebraic equations is modelled through an approximation that is close to the consistent formulation. By using the framework of a$K\text{{\ndash}} \omega $model (where$K$is turbulent kinetic energy and$\omega $an inverse time scale) and, where needed, near-wall corrections, the model is applied to homogeneous shear flow and turbulent channel flow, both with stable stratification. For the case of homogeneous shear flow, the model predicts a critical Richardson number of 0.25 above which the turbulent kinetic energy decays to zero. The channel-flow results agree well with DNS data. Furthermore, the model is shown to be robust and approximately self-consistent. It also fulfils the requirements of realizability.

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Fast measurements of the electron temperature and parallel heat flux in ELMy H-mode on the COMPASS tokamak

Nuclear Fusion ◽

10.1088/0029-5515/57/2/022010 ◽

2016 ◽

Vol 57 (2) ◽

pp. 022010 ◽

Cited By ~ 7

Author(s):

J. Adamek ◽

J. Seidl ◽

M. Komm ◽

V. Weinzettl ◽

R. Panek ◽

...

Keyword(s):

Heat Flux ◽

Electron Temperature

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Magnetorotational instability in cool cores of galaxy clusters

Journal of Plasma Physics ◽

10.1017/s0022377815000781 ◽

2015 ◽

Vol 81 (5) ◽

Cited By ~ 3

Author(s):

Carlo Nipoti ◽

L. Posti ◽

S. Ettori ◽

M. Bianconi

Keyword(s):

Heat Flux ◽

Heat Conduction ◽

Galaxy Clusters ◽

Magnetized Plasma ◽

Radiative Cooling ◽

Clusters Of Galaxies ◽

Magnetorotational Instability ◽

X Ray ◽

Stability Properties ◽

Anisotropic Heat Conduction

Clusters of galaxies are embedded in halos of optically thin, gravitationally stratified, weakly magnetized plasma at the system’s virial temperature. Owing to radiative cooling and anisotropic heat conduction, such intracluster medium (ICM) is subject to local instabilities, which are combinations of the thermal, magnetothermal and heat-flux-driven buoyancy instabilities. If the ICM rotates significantly, its stability properties are substantially modified and, in particular, also the magnetorotational instability (MRI) can play an important role. We study simple models of rotating cool-core clusters and we demonstrate that the MRI can be the dominant instability over significant portions of the clusters, with possible implications for the dynamics and evolution of the cool cores. Our results give further motivation for measuring the rotation of the ICM with future X-ray missions such as ASTRO-H and ATHENA.

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