Труды сотрудников ИВМ СО РАН

/ N. V. Erkaev [et al.] // Geophys. Res. Lett. - 2012. - Vol. 39. - Ст. L01103, DOI 10.1029/2011GL050209. - Cited References: 16. - This work was done while NVE was on a research visit to the Space Science Center of UNH. This work is supported by RFBR grant N 09-05-91000-ANF_a, and also by the Austrian "Fonds zur Forderung der wissenschaftlichen Forschung" under Project I 193-N16 and the "Verwaltungsstelle fur Auslandsbeziehungen" of the Austrian Academy of Sciences. Work by CJF was supported by NASA grants NNX10AQ29G and NNX08AD11G. . - ISSN 0094-8276РУБ Geosciences, Multidisciplinary

Аннотация: In previous work we used a semi-analytical treatment to describe accelerated magnetosheath flows caused by the draping of interplanetary magnetic field (IMF) lines around the magnetosphere. Here, we use the same approach, i.e., modeling the magnetic field lines as elastic strings, to examine how the magnetic tension force, one of the two agents responsible for producing these flows, varies along field lines away from the equatorial plane. The bend in the field line caused by the draping mechanism propagates as two oppositely-directed waves to higher latitudes. For a due northward IMF - the case we consider here - these propagate symmetrically north/south of the equatorial plane. As a result, a two-peaked latitude velocity profile develops as we go further downtail and the velocity peaks migrate along the magnetic field line to higher latitudes. We examine this velocity-profile for two Alfven Mach numbers (M-A = 8 and 3), representative of conditions in the solar wind at 1 AU ("normal" solar wind and solar transients). Qualitatively, the picture is the same but quantitatively there are important differences: (i) the flows reach higher values for the lower M-A (maximum V/V-SW = 1.6) than for the higher M-A (V/V-SW = 1.3); (ii) asymptotic values are reached farther downstream of the dawn-dusk terminator for the lower M-A (similar to-50 R-E vs -15 R-E); (iii) For the lower M-A the highest speeds are reached away from the equatorial plane. We predict two channels of fast magnetosheath flow next to the magnetopause at off-equatorial latitudes that exceed the solar wind speed. Citation: Erkaev, N. V., C. J. Farrugia, A. V. Mezentsev, R. B. Torbert, and H. K. Biernat (2012), Accelerated magnetosheath flows caused by IMF draping: Dependence on latitude, Geophys. Res. Lett., 39, L01103, doi:10.1029/2011GL050209.

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Доп.точки доступа:
Erkaev, N.V.; Еркаев, Николай Васильевич; Farrugia, C.J.; Mezentsev, A.V.; Torbert, R.B.; Biernat, H.K.

[Text] / M. Ampferer [et al.] // Ann. Geophys. - 2010. - Vol. 28, Is. 3. - pp. 779-787. - Cited References: 30. - This work is supported by grants 07 05 00135, 09-06-91000 from the Russian Foundation for Basic Research and by the Program 16.3 of the Russian Academy of Sciences. Additional support is due to the Austrian "Fonds zur Forderung der wissenschaftlichen Forschung" under Project I193-N16 and the "Verwaltungsstelle fur Auslandsbeziehungen" of the Austrian Academy of Sciences. The authors are grateful to the referees whose comments helped considerably to improve the paper. . - ISSN 0992-7689РУБ Astronomy & Astrophysics + Geosciences, Multidisciplinary + Meteorology & Atmospheric Sciences

Аннотация: It is well known that lithospheric electromagnetic emissions are generated before earthquakes occurrence. In our study, we consider the physical penetration mechanism of the electric field from the Earth's surface, through the atmosphere-ionosphere layers, and until its detection in space by satellites. A simplified approach is investigated using the electric conductivity equation, i.e., del((sigma) over cap.del Phi) = 0 in the case of a vertical inclination of the geomagnetic field lines. Particular interest is given to the conductivity profile near the ground and the electric field distribution at the Earth's surface. Our results are discussed and compared to the models of Pulinets et al. (2003) and Denisenko et al. (2008). It is shown that the near ground atmospheric layer with low conductivity decreases the electric field penetration into the ionosphere. The model calculations have demonstrated that the electric field of lithospheric origin is too weak to be observed at satellite altitudes.


Доп.точки доступа:
Ampferer, M.; Denisenko, V.V.; Денисенко, Валерий Васильевич; Hausleitner, W.; Krauss, S.; Stangl, G.; Boudjada, M.Y.; Biernat, H.K.

[Text] / H. K. Biernat [et al.] // Nonlinear Process Geophys. - 2000. - Vol. 7: 24th General Assembly of the European-Geophysical-Society (APR 19-23, 1999, THE HAGUE, NETHERLANDS), Is. 03.04.2013. - P201-209. - Cited References: 34 . - ISSN 1023-5809РУБ Geochemistry & Geophysics + Meteorology & Atmospheric Sciences

Аннотация: The study of the interaction of the solar wind with magnetized and unmagnetized planets forms a central topic of space research. Focussing on planetary magnetosheaths, we review some major developments in this field. Magnetosheath structures depend crucially on the orientation of the interplanetary magnetic field, the solar wind Alfven Mach number, the shape of the obstacle (axisymmetric/non-axisymmetric, etc.), the boundary conditions at the magnetopause (low/high magnetic shear), and the degree of thermal anisotropy of the plasma. We illustrate the cases of Earth, Jupiter and Venus. The terrestrial magnetosphere is axisymmetric and has been probed in situ by many spacecraft. Jupiter's magnetosphere is highly non-axisymmetric. Furthermore, we study magnetohydrodynamic effects in the Venus magnetosheath.


Доп.точки доступа:
Biernat, H.K.; Erkaev, N.V.; Еркаев, Николай Васильевич; Farrugia, C.J.; Vogl, D.F.; Schaffenberger, W.

[Text] / N. V. Erkaev [et al.] // COORDINATED MEASUREMENTS OF MAGNETOSPHERIC PROCESSES. Ser. ADVANCES IN SPACE RESEARCH : PERGAMON PRESS LTD, 2000. - Vol. 25: D0 1 Symposium of COSPAR Scientific Commission D Held at the 32nd COSPAR Scientific Assembly (JUL 12-19, 1998, NAGOYA, JAPAN), Is. 07.08.2013. - P1523-1528, DOI 10.1016/S0273-1177(99)00665-1. - Cited References: 18 . - ISBN 0273-1177РУБ Engineering, Aerospace + Astronomy & Astrophysics + Geosciences, Multidisciplinary + Meteorology & Atmospheric Sciences

Аннотация: We extend our "magnetic string" MHD model describing the flow of the shocked solar wind around the magnetosphere to include an anisotropic plasma pressure with p(perpendicular to) p(parallel to). Thermodynamic properties are determined by the law of conservation of energy of a magnetic string associated with a magnetic field line. The MHD equations are closed by a relation between p(perpendicular to) and p(parallel to) corresponding to the threshold of the electromagnetic proton cyclotron wave instability. Assuming no flow across the magnetopause, we compare profiles of the steady-state magnetic field and plasma parameters along the subsolar line for upstream sonic and Alfven Mach numbers = 10 with the isotropic case (p(perpendicular to) = p(parallel to)). In the anisotropic model, besides the density, both temperatures, plasma pressures and betas decrease toward the magnetopause. The temperature and plasma pressure parallel to the magnetic field decrease more strongly than those perpendicular to the field. Profiles for temperature and pressure in the case of isotropy lie between those of corresponding parallel and perpendicular values, but closer to the latter. The gradient of B near the magnetopause is larger than for isotropic pressure. (C) 2000 COSPAR. Published by Elsevier Science Ltd.


Доп.точки доступа:
Erkaev, N.V.; Еркаев, Николай Васильевич; Farrugia, C.J.; Biernat, H.K.; Ogilvie, K.W.; Quinn, J.M.

[Text] / N. V. Erkaev, C. J. Farrugia, H. K. Biernat // J. Geophys. Res-Space Phys. - 1999. - Vol. 104, Is. A4. - P6877-6887, DOI 10.1029/1998JA900134. - Cited References: 29 . - ISSN 0148-0227РУБ Astronomy & Astrophysics

Аннотация: We present a three-dimensional, one-fluid, steady state magnetohydrodynamic (MHD) model of magnetosheath flow near the subsolar line with unequal plasma pressures perpendicular (P-perpendicular to) and parallel (P-parallel to) to the magnetic field (P-perpendicular to P-parallel to) Aside from an assumption on the total pressure normal to the magnetopause, our analytical-numerical method is completely general and is an extension of our isotropic, "magnetic string" MHD model, which we describe in detail here. The MHD equations are closed by a relation between P-perpendicular to and P-parallel to as in the Bounded Anisotropy Model [Denton et al., 1994] corresponding to the threshold of the electromagnetic proton cyclotron wave instability. We take an IMF oriented perpendicular to the solar wind velocity. As boundary conditions, we have Rankine-Hugoniot relations at the bow shock and a no-flow condition at the magnetopause. We obtain steady state profiles of the magnetic field and plasma parameters for upstream sonic and Alfven Mach numbers equal to 10, and compare them with the isotropic case (P-parallel to = P-perpendicular to). Anisotropy slightly thickens the magnetosheath. In the anisotropic model, the density, the parallel and perpendicular temperatures, plasma pressures, and betas all decrease toward the magnetopause. Isotropic profiles lie between those of quantities perpendicular and parallel to the field. Anisotropy has considerable effect on the density profile, which lies below that in the isotropic limit throughout the magnetosheath. Density depletion results from stretching of magnetic field lines, which is caused by field-aligned plasma flow. Approaching the magnetopause, the tangential component of velocity parallel to the magnetic field decreases, while the tangential component perpendicular to the magnetic field increases. These are features characterizing a stagnation line flow at the magnetopause. The acceleration along the magnetic field is produced by the gradient of P-parallel to and the mirror force, which depends on anisotropy. They both make substantial contributions and are responsible for the changes we see;from isotropy. The acceleration perpendicular to magnetic field is also larger than in the case of isotropy and is caused by the gradient of total pressure, the magnetic strength, and the mirror force. In addition, acceleration in both directions is affected by the decreasing density.


Доп.точки доступа:
Erkaev, N.V.; Еркаев, Николай Васильевич; Farrugia, C.J.; Biernat, H.K.

[Text] / C. J. Farrugia [et al.] // Ann. Geophys.-Atmos. Hydrospheres Space Sci. - 1998. - Vol. 16, Is. 5. - P518-527, DOI 10.1007/s00585-998-0518-7. - Cited References: 24 . - ISSN 0992-7689РУБ Astronomy & Astrophysics + Geosciences, Multidisciplinary + Meteorology & Atmospheric Sciences

Аннотация: We compare numerical results obtained from a steady-state MHD model of solar wind flow past the terrestrial magnetosphere with documented observations made by the AMPTE!IRM spacecraft on 24 October, 1985, during an inbound crossing of the magnetosheath. Observations indicate that steady conditions prevailed during this about 4 hour-long crossing. The magnetic shear at spacecraft entry into the magnetosphere was 15 degrees. A steady density decrease and a concomitant magnetic field pile-up were observed during the 40 min interval just preceding the magnetopause crossing. In this plasma depletion layer (1) the plasma beta dropped to values below unity; (2) the flow speed tangential to the magnetopause was enhanced; and (3) the local magnetic field and velocity vectors became increasingly more orthogonal to each other as the magnetopause was approached (Phan er al., 1994). We model parameter variations along a spacecraft orbit approximating that of AMPTE/IRM, which was at slightly southern GSE latitudes and about 1.5 h post-noon Local Time. We model the magnetopause as a tangential discontinuity, as suggested by the observations, and take as input solar wind parameters those measured by AMPTE/IRM just prior to its bow shock crossing. We find that computed field and plasma profiles across the magnetosheath and plasma depletion layer match all observations closely. Theoretical predictions on stagnation line flow near this low-shear magnetopause are confirmed by the experimental findings. Our theory does not give, and the data on this pass do not show, any localized density enhancements in the inner magnetosheath region just outside the plasma depletion layer.


Доп.точки доступа:
Farrugia, C.J.; Biernat, H.K.; Erkaev, N.V.; Еркаев, Николай Васильевич; Kistler, L.M.; Le, G.; Russell, C.T.

[Text] / C. J. Farrugia, H. K. Biernat, N. V. Erkaev // Planet Space Sci. - 1998. - Vol. 46, Is. 5. - P507-514, DOI 10.1016/S0032-0633(97)00225-0. - Cited References: 20 . - ISSN 0032-0633РУБ Astronomy & Astrophysics

Аннотация: The solar wind flow past nonaxisymmetric magnetospheres exhibits features which are absent in the case of axisymmetric magnetospheres such as that of Earth. We discuss results obtained by a numerical integration of the dissipationless MHD equations, under simplifying assumptions, and apply them to the two outer planets Jupiter and Saturn, both of whose magnetospheres depart substantially from axisymmetry. We model these magnetospheres as paraboloids with two different radii of curvature at the subsolar point, L-0 and L-1, where L-0 and L-1 refer to a magnetopause cut containing the rotational axis, and to the rotational equator, respectively (L-0 L-1). The degree of flattening is expressed by a parameter q :


Доп.точки доступа:
Farrugia, C.J.; Biernat, H.K.; Erkaev, N.V.; Еркаев, Николай Васильевич

[Text] / C. J. Farrugia [et al.] // J. Geophys. Res-Space Phys. - 1998. - Vol. 103, Is. A4. - P6703-6727DOI 10.1029/97JA03248. - Cited References: 39 . - РУБ Astronomy & Astrophysics

Аннотация: We present maximum growth rate charts of the Kelvin-Helmholtz (KH) and Rayleigh-Taylor (RT) instabilities at the dayside magnetopause (MP), considering two orientations of the interplanetary magnetic field (IMF) (due north and 30 degrees west of north). We input parameters in the plasma depletion layer calculated from an MHD code. We study both a sharp MP transition and an MP with an attached boundary layer ("thin" and "thick" approximations, respectively). Our analysis applies to wavelengths (lambda) from similar to 2 x 10(3) km to less than or equal to 9 R-E. Thin model results are as follows: For a stationary MP and due north IMF, the off-noon, low-latitude MP is very low shear (less than or equal to 10 degrees) and is substantially KH active. With an IMF inclined to north, extremely low shear, KH-active regions are confined to two strips, one in each hemisphere, where short lambda perturbations are generated, which propagate as surface ripples on the high-latitude, duskside MP. For a sunward accelerating magnetopause and IMF north, a large part of the MP is unstable. With an inclined IMF, the KH+RT unstable strips are broader and growth rates are higher. Thick model results are as follows: For IMF due north and a stationary MP, the middle-to high-latitude MP is stable. At middle to low latitudes, the inner edge of the boundary layer (IEBL) is active, except fora 2-hour local time band on either side of noon. For the inclined IMF, the MP is stable for long lambda, with activity for short lambda confined to two strips, as before, with slightly reduced growth rates. For the IEBL, a clear dawn-dusk asymmetry in KH activity is evident. When the MP accelerates sunward and the IMF points north, we have to consider also the lambda of the perturbation. For short lambda, growth rates are enhanced with respect to stationarity at both the NIP and the IEBL. While there are extensive regions of negligible growth at the MP, the entire IEBL is RT + KH unstable. We give an example of a long lambda perturbation where both interfaces are coupled and oscillate together. Finally, for an inclined IMF, we have at the MP unstable strips which are wider and have higher growth rates. The IEBL, by contrast, is completely destabilized, with larger growth rates than under stationary conditions.

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Доп.точки доступа:
Farrugia, C.J.; Gratton, F.T.; Bender, L.; Biernat, H.K.; Erkaev, N.V.; Еркаев, Николай Васильевич; Quinn, J.M.; Torbert, R.B.; Denisenko, V.V.; Денисенко, Валерий Васильевич

[Text] / C. J. Farrugia [et al.] // SOLAR-TERRESTRIAL RELATIONS: PREDICTING THE EFFECTS ON THE NEAR- EARTH ENVIRONMENT. Ser. ADVANCES IN SPACE RESEARCH : PERGAMON PRESS LTD, 1998. - Vol. 22: DO 7 Symposium of COSPAR Scientific-Commission-D on Solar-Terrestrial Relations - Predicting the Effects on the Near-Earth Environment at the 31st COSPAR Sci Assembly (JUL 14-21, 1996, BIRMINGHAM, ENGLAND), Is. 1. - P67-72, DOI 10.1016/S0273-1177(97)01102-2. - Cited References: 19 . - ISBN 0273-1177. - ISBN 0-08-043465-7РУБ Engineering, Aerospace + Astronomy & Astrophysics + Geosciences, Multidisciplinary + Meteorology & Atmospheric Sciences

Аннотация: We compare numerical results of a steady-state MHD model for solar wind flow past the terrestrial magnetosphere with documented observations made by the AMPTE/IRM spacecraft on 24 October, 1985, during an inbound crossing of the magnetosheath. Observations indicate that steady conditions prevail during this similar to 4 hour-long crossing. The magnetic shear at entry into the magnetosphere was 15 deg. A steady density decrease and a concomitant magnetic field pile-up were observed during the similar to 40 min interval just preceding the magnetopause crossing. In this so-called plasma depletion layer (i) the plasma beta fell generally below unity; (ii) the flow speed tangential to the magnetopause was enhanced; and (iii) the local magnetic field and velocity vectors became increasingly more orthogonal to each other as the magnetopause was approached (Phan et al., 1994). We model parameter variations along a orbit similar to the AMPTE/IRM trajectory, which was at slightly southerly latitudes and similar to 1.5 hours post-noon local time (GSE). In our model we consider the magnetopause to be a tangential discontinuity, as suggested by the observations, and take as input solar wind parameters those measured by AMPTE/IRM just prior to its bow shock crossing. We find that theoretical predictions match all observations closely. (C) 1998 COSPAR. Published by Elsevier Science Ltd. All rights reserved.


Доп.точки доступа:
Farrugia, C.J.; Biernat, H.K.; Erkaev, N.V.; Еркаев, Николай Васильевич; Kistler, L.M.

[Text] / C. J. Farrugia [et al.] // J. Geophys. Res-Space Phys. - 1997. - Vol. 102, Is. A6. - P11315-11324DOI 10.1029/97JA00410. - Cited References: 29 . - РУБ Astronomy & Astrophysics

Аннотация: Together with the magnetic shear across the magnetopause, the solar wind Alfven Mach number, M-A infinity plays a central role in determining the structure of the magnetosheath. Recent theoretical modeling has shown, in particular, that as M-A infinity decreases, the region adjacent to the sunward side of the magnetopause where the interplanetary magnetic field (IMF) exerts a strong influence on the flow (i.e., the so-called ''plasma depletion layer''), is no longer confined to a thin layer similar to 0.3 Earth radii (R-E) thick but occupies an increasingly larger fraction of the magnetosheath. Furthermore, the model predicts the possibility of a plasma depletion layer for low M-A infinity, irrespective of the size of the magnetic shear at the magnetopause, In this paper we study three examples of low latitude ISEE 2 passes through the dayside magnetosheath near noon: December 3, 1979; October 5, 1979; and November 11, 1979, In all three examples, MA, was lower than normal. During the December 3 pass (which we treat qualitatively), we find evidence of a plasma depletion layer when the IMF was pointing south, On the other two passes (which we study quantitatively), the interplanetary magnetic field was strongly northward pointing, leading to low magnetic shear at the respective magnetopause crossings, The October 5 pass was under steady interplanetary conditions and we find good agreement between theory and data, Temporal variations of the interplanetary medium during the November 11 pass necessitated an extension of the steady state theory to encompass piecewise steady (on average) interplanetary conditions, Better agreement with the data results when the theory is extended further to correct the total pressure at the sunward side of the magnetopause by integrating the magnetic tension term across the layer. For wide plasma depletion layers, this correction can be substantial.


Доп.точки доступа:
Farrugia, C.J.; Erkaev, N.V.; Еркаев, Николай Васильевич; Biernat, H.K.; Lawrence, G.R.; Elphic, R.C.

[Text] / V. V. Denisenko [et al.] // Nat. Hazards Earth Syst. Sci. - 2008. - Vol. 8, Is. 5. - P1009-1017. - Cited References: 60. - This work is supported by grant 07-05-00135 from the Russian Foundation for Basic Research and by the Programs 16.3 and 2.16 of the Russian Academy of Sciences. Further support is due to the Austrian "Fonds zur Forderung der wissenschaftlichen Forschung" under project P20145-N16. We acknowledge support by the Austrian Academy of Sciences, "Verwaltungstelle fur Auslandsbeziehungen", and the Russian Academy of Sciences. Part of this research was done during academic visits of V. V. 'Denisenko to the Space Research Institute of the Austrian Academy of Sciences in Graz as well as during an academic visit of H. K. Biernat to the Institute of Computational Modelling of the Russian Academy of Sciences in Krasnoyarsk. . - ISSN 1561-8633РУБ Geosciences, Multidisciplinary + Meteorology & Atmospheric Sciences + Water Resources

Аннотация: The classic approach to calculate the electrostatic field penetration, from the Earth's surface into the ionosphere, is to consider the following equation del. ((sigma) over cap del Phi) =0 where (sigma) over cap and Phi are the electric conductivity and the potential of the electric field, respectively. The penetration characteristics strongly depend on the conductivities of atmosphere and ionosphere. To estimate the electrostatic field penetration up to the orbital height of DEMETER satellite (about 700 km) the role of the ionosphere must be analyzed. It is done with help of a special upper boundary condition for the atmospheric electric field. In this paper, we investigate the influence of the ionospheric conductivity on the electrostatic field penetration from the Earth's surface into the ionosphere. We show that the magnitude of the ionospheric electric field penetrated from the ground is inverse proportional to the value of the ionospheric Pedersen conductance. So its typical value in day-time is about hundred times less than in night-time.


Доп.точки доступа:
Denisenko, V.V.; Денисенко, Валерий Васильевич; Boudjada, M.Y.; Horn, M.; Pomozov, E.V.; Помозов, Егор Владимирович; Biernat, H.K.; Schwingenschuh, K.; Lammer, H.; Prattes, G.; Cristea, E.

[Text] / N. V. Erkaev [et al.] // Geophys. Res. Lett. - 2011. - Vol. 38. - Ст. L01104, DOI 10.1029/2010GL045998. - Cited References: 20. - This work was done while N.V.E. was on a research visit to the Space Science Center of UNH. This work is supported by RFBR grant N 09-05-91000-ANF_a and also by the Austrian "Fonds zur Forderung der wissenschaftlichen Forschung" under project I 193-N16 and the "Verwaltungsstelle fur Auslandsbeziehungen" of the Austrian Academy of Sciences. Work by C.J.F. was supported by NASA grants NNX10AQ29G and NNX08AD11G. . - ISSN 0094-8276РУБ Geosciences, Multidisciplinary

Аннотация: We study the acceleration of magnetosheath plasma using a semi-analytical magnetic string approach for a range of solar wind Alfven Mach numbers, M-A, between 2 and 20. We work with an IMF vector perpendicular to the solar wind velocity, V-sw, and pointing north. We do not invoke magnetic reconnection. Our results indicate that magnetosheath speeds can exceed the solar wind speed, and the ratio V/V-sw increases with decreasing M-A. Analyzing the dependence of this ratio on M-A, we find that for M-A = 2, maximum V/V-sw approximate to 1.6, and for M-A = 10-20, maximum V/V-sw varies from 1.21 to 1.13. Maximum speeds occur a few Earth radii (R-E) tailward of the dawn-dusk terminator. The thickness of the accelerated flow layer varies as M-A(-2). Taking the magnetopause subsolar distance as 10 R-E, we find typical values for the thickness of similar to 4 R-E for M-A = 3 and 0.35 R-E for M-A = 10. The physical mechanism is that of draping of the magnetic field lines around the magnetosphere, and the associated magnetic tension and total pressure gradient forces acting on the flow. For lower M-A the plasma depletion is stronger, and thus the acceleration produced by the pressure gradient is larger. An additional acceleration is produced by the magnetic tension, which is stronger for smaller M-A. At the dayside the pressure gradient and magnetic tension forces both act in the same direction. But tailward of the terminator the magnetic tension starts to act in the opposite direction to the pressure gradient. When the resulting force vanishes, the highest speed is attained. Citation: Erkaev, N. V., C. J. Farrugia, B. Harris, and H. K. Biernat (2011), On accelerated magnetosheath flows under northward IMF, Geophys. Res. Lett., 38, L01104, doi: 10.1029/2010GL045998.


Доп.точки доступа:
Erkaev, N.V.; Еркаев, Николай Васильевич; Farrugia, C.J.; Harris, B.; Biernat, H.K.

[Text] / D. B. Korovinskiy [et al.] // J. Geophys. Res-Space Phys. - 2011. - Vol. 116. - Ст. A05219, DOI 10.1029/2010JA015942. - Cited References: 45. - This work is supported by the Austrian Science Fund under projects I193-N16 and P21051-N16, by RFBR grant 09-05-91000-ANF-a, and by SPSU grant 11.38.47.2011. V. S. Semenov also thanks ISSI for hospitality and financial support. . - ISSN 2169-9380РУБ Astronomy & Astrophysics

Аннотация: A 2.5-D analytical electron Hall magnetohydrodynamic model of steady state magnetic reconnection in a collisionless compressible plasma with a constant electron temperature is developed. It is shown that as in the incompressible case, the solution of the Grad-Shafranov equation for the magnetic potential is a basis for the problem analysis. The formation of the double electric layers and layers of low-density plasma, mapping the magnetic separatrices, are investigated. It is found that the formation of depletion layers should not be governed by the out-of-plane magnetic field, but rather, the origin of these layers lies inside the electron diffusion region. The double electric layers are found to be thin separatrices-elongated sheets, whose cross sections are of the order of the electron diffusion region half width. These charged layers provide the presence of the strong electric field orthogonal to the in-plane projection of the magnetic field, which forces electrons to accelerate into the out-of-plane direction. Outside of the double electric layers, the condition of quasi-neutrality of the plasma is found to be fulfilled to high accuracy.


Доп.точки доступа:
Korovinskiy, D.B.; Semenov, V.S.; Erkaev, N.V.; Еркаев, Николай Васильевич; Divin, A.V.; Biernat, H.K.; Mostl, U.V.