Труды сотрудников ИВМ СО РАН

[Text] : статья / N.V. Erkaev [et al.] // International journal of geomagnetism and aeronomy. - 2002. - Vol. 3, № 1. - p. 67-76
Аннотация: One aspect of the Io-Jupiter interaction studied by many authors is the generation of Alfv_en waves by Io moving in the magnetized plasma. In our study, we focus on an additional mechanism of the interaction between Io and Jupiter based on MHD slow shocks propagating from Io toward Jupiter along a magnetic ux tube. These MHD slow shocks are produced by plasma ow injected by Io, which is considered as a source of ionized particles. The propagation of the slow shocks is calculated along a given magnetic ux tube from Io to Jupiter. The total pressure is assumed to be a known function of the distance measured along the tube. It is determined as the magnetic pressure corresponding to the undisturbed Jovian magnetic field calculated in a dipole approximation. The material coordinates are used to describe the plasma ow along the magnetic tube. The peculiarity of this problem stems from the fact that the total pressure increases by a factor of 105, whereas the cross section of the magnetic ux tube decreases by a factor of 300. The result is that the plasma velocity after the shock front substantially increases toward Jupiter with increasing magnetic pressure. The electric potential difference along the magnetic field is estimated, which is produced by the accelerated plasma ow propagating with the MHD slow shocks.

http://icm.krasn.ru/refextra.php?id=2436,
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ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44

Доп.точки доступа:
Erkaev, N.V.; Еркаев, Николай Васильевич; Semenov, V.S.; Семенов В. С.; Shaidurov, V.A.; Шайдуров В.А.; Langmayr, D.; Biernat, H.K.; Rucker, H.O.

[Text] : статья / N.V. Erkaev, V.A. Shaidurov, V.S. Semenov, H.K. Biernat // Nonlinear Processes in Geophysics. - 2002. - Vol. 9. - p. 163-172
Аннотация: Variations of the plasma pressure in a magnetic flux tube can produce MHD waves evolving into shocks. In the case of a low plasma beta, plasma pressure pulses in the magnetic flux tube generate MHD slow shocks propagating along the tube. For converging magnetic field lines, such as in a dipole magnetic field, the cross section of the mag-netic flux tube decreases enormously with increasing mag-netic field strength. In such a case, the propagation of MHD waves along magnetic flux tubes is rather different from that in the case of uniform magnetic fields. In this paper, the propagation of MHD slow shocks is studied numerically us-ing the ideal MHD equations in an approximation suitable for a thin magnetic flux tube with a low plasma beta. The results obtained in the numerical study show that the jumps in the plasma parameters at the MHD slow shock increase greatly while the shock is propagating in the narrowing mag-netic flux tube. The results are applied to the case of the interaction between Jupiter and its satellite Io, the latter be-ing considered as a source of plasma pressure pulses.

http://icm.krasn.ru/refextra.php?id=2437,
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ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44

Доп.точки доступа:
Shaidurov, V.A.; Шайдуров В.А.; Semenov, V.S.; Семенов В. С.; Biernat, H.K.; Еркаев, Николай Васильевич

[Текст] : монография / O. Sadovskaya, V. Sadovskii. - Berlin ; Heidelberg : Springer-Verlag, 2012. - 390 p. : il. - (Advanced Structured Materials, ISSN 1869-8433 ; vol. 21), ISSN 1869-8441 (electronic)). - Bibliogr. at the end of the chapters. - ISBN 978-3-642-29052-7. - ISBN 978-3-642-29053-4 (eBook) : Б. ц.ББК В25

Аннотация: This monograph contains original results in the field of mathematical and numerical modeling of machanical behavior of granular materials and materials with different strengths. It proposes new models helping to define zones of the strain localization. The book shows how to analyze processes of the propogation of elastic and elastic-plastic waves in loosened materials, and constructs models of mixed type, describing the flow of granular materials in the presence of quasi-static deformation zones. In a last part? the book studies a numerical realization of the models on multiprocessor computer systems. The book is intended for scientific researchers, lecturers of universities, postgraduates and senior students, who specialize in the field of the deformable materials mechanics, mathematical modeling and adjacent field of applied and calculus mathematics

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Доп.точки доступа:
Sadovskii, V.M.; Садовский, Владимир Михайлович; Садовская, Оксана Викторовна
Экземпляры всего: 1
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Свободны: ЗФ (1)

[Текст] : статья / E. D. Karepova, E. Dementyeva // Parallel Computing Technologies. - 2011. - Vol. 6873. - p. 444-451. - (Lecture Notes in Computer Science)DOI 10.1007/978-3-642-23178-0_39 . -
Аннотация: The ill-posed inverse problem of propagation of long waves in a domain of arbitrary form with the sufficiently smooth boundary on a sphere is consider. Numerical solution is based on finite elements method. Parallel software using MPI is performed. We compared efficiency of two popular implementations of the MPI standard and studied the behavior of our software when using various ways of memory allocation.

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Dementyeva, E.V.; Дементьева, Екатерина Васильевна; Карепова, Евгения Дмитриевна

[Text] : статья / E.D. Karepova, E. Dementyeva // Parallel Computing Technologies. - 2013. - Vol. 8236. - p. 345-354
Аннотация: The problem of propagation of long waves in a domain of an arbitrary form with the sufficiently smooth boundary on a sphere is considered. The boundary consists of “solid” parts passing along the coastline and “open liquid” parts passing through the water area. In general case the influence of the ocean through an open boundary is unknown and must be found together with components of a velocity vector and free surface elevation. For this purpose we use observation data of free surface elevation given only on a part of an “open liquid” boundary. We solve our ill-posed inverse problem by an approach based on the optimal control methods and adjoint equations theory.

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Dementyeva, E.V.; Дементьева, Екатерина Васильевна; Карепова, Евгения Дмитриевна

/ N.V. Erkaev, V.S. Semenov, H.K. Biernat // Phys. Plasmas. - 2012. - Vol. 19, Is. 6. - Ст. 62905, DOI 10.1063/1.4725506. - Cited References: 22. - This work is supported by RFBR Grants Nos. 12-05-00152-a and 12-05-00918-a, and also by St. Petersburg University grant. V. S. S. and H. K. B. are supported from the FP7 Programme under Grant No. 269198-Geoplasmas (Marie Curie Exchange Scheme). Additional support is due to the Austrian "Fonds zur Forderung der wissenschaftlichen Forschung" under Project I 193-N16 and the "Verwaltungsstelle fur Auslandsbeziehungen" of the Austrian Academy of Sciences. . - ISSN 1070-664XРУБ Physics, Fluids & Plasmas

Аннотация: Magnetic filament approach is applied for modeling of nonlinear "kink"-like flapping oscillations of thin magnetic flux tubes in the Earth's magnetotail current sheet. A discrete approximation for the magnetic flux tube was derived on a basis of the Hamiltonian formulation of the problem. The obtained system of ordinary differential equations was integrated by method of Rosenbrock, which is suitable for stiff equations. The two-dimensional exact Kan's solution of the Vlasov equations was used to set the background equilibrium conditions for magnetic field and plasma. Boundary conditions for the magnetic filament were found to be dependent on the ratio of the ionospheric conductivity and the Alfven conductivity of the magnetic tube. It was shown that an enhancement of this ratio leads to the corresponding increase of the frequency of the flapping oscillations. For some special case of boundary conditions, when the magnetic perturbations vanish at the boundaries, the calculated frequency of the "kink"-like flapping oscillations is rather close to that predicted by the "double gradient" analytical model. For others cases, the obtained frequency of the flapping oscillations is somewhat larger than that from the "double gradient" theory. The frequency of the nonlinear flapping oscillations was found to be a decreasing function of the amplitude. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4725506]


Доп.точки доступа:
Erkaev, N.V.; Еркаев, Николай Васильевич; Semenov, V.S.; Biernat, H.K.

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

/ V. M. Sadovskii, O. V. Sadovskaya ; ed. by T.E.Simos [et al.] // NUMERICAL ANALYSIS AND APPLIED MATHEMATICS (ICNAAM 2012), VOLS A AND B. Ser. AIP Conference Proceedings : AMER INST PHYSICS, 2012. - Vol. 1479: International Conference of Numerical Analysis and Applied Mathematics (ICNAAM) (SEP 19-25, 2012, Kos, GREECE). - pp. 1611-1614, DOI 10.1063/1.4756474. - Cited References: 4 . - ISBN 0094-243X. - ISBN 978-0-7354-1091-6РУБ Mathematics, Applied + Physics, Applied

Аннотация: Parallel program systems for numerical solution of 2D and 3D problems of the dynamics of deformable media with constitutive relationships of rather general form on the basis of universal mathematical model describing small strains of elastic, elastic-plastic and granular materials are worked out. Some computations of dynamic problems with and without taking into account the moment properties of a material were performed on supercomputers with cluster architecture.

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Доп.точки доступа:
Sadovskii, V.M.; Садовский, Владимир Михайлович; Sadovskaya, O.V.; Садовская, Оксана Викторовна; Simos, T.E. \ed.\; Psihoyios, G. \ed.\; Tsitouras, C. \ed.\

/ V.D. Suvorov [et al.] // Russian Geology and Geophysics. - 2013. - Vol. 54, Is. 9. - pp. 1108-1120, DOI 10.1016/j.rgg.2013.07.023 . - ISSN 1068-7971
Аннотация: The upper-mantle structure was studied from first-arrival data along the Meteorite profile, run using underground nuclear explosions. Unlike the layered, slightly inhomogeneous models in the previous works, emphasis was laid on lateral inhomogeneity at the minimum possible number of abrupt seismic boundaries. We used forward ray tracing of the traveltimes of refracted and overcritical reflected waves. The model obtained is characterized by considerable velocity variations, from 7.7 km/s in the Baikal Rift Zone to 8.0-8.45 km/s beneath the Tunguska syneclise. A layer of increased velocity (up to 8.5-8.6 km/s), 30-80 km thick, is distinguished at the base of seismic lithosphere. The depth of the layer top varies from 120 km in the northern Siberian craton to 210 km in its southeastern framing. It has been shown that, with crustal density anomalies excluded, the reduced gravity field is consistent with the upper-mantle velocity model. В© 2013.

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Suvorov, V.D.; Mel'nik, E.A.; Mishen'kina, Z.R.; Pavlov, E.V.; Kochnev, V.A.; Кочнев, Владимир Алексеевич

[Text] / O.V. Sadovskaya, V.M. Sadovskii // Acoust. Phys. - 2010. - Vol. 56, Is. 6. - P942-950, DOI 10.1134/S1063771010060199. - Cited References: 19. - This study was supported by the Russian Foundation for Basic Research (project no. 08-01-00148), Complex Fundamental Research Program no. 2 of the Presidium of the Russian Academy of Sciences, and Siberian Division of the Russian Academy of Sciences (Interdisciplinary Integration Project no. 40). . - 9. - ISSN 1063-7710РУБ Acoustics

Аннотация: Oscillatory processes in media with microstructure under the action of concentrated impulse and time-periodic perturbations are analyzed within the Cosserat elasticity theory. According to the results of computations, such media are characterized by a resonance frequency equal to the frequency of natural oscillations of particle rotational motion. This frequency is a phenomenological parameter of a material. It was established that the oscillatory rotation of particles changes for monotone rotational motion with increasing intensity of shear strains.


Доп.точки доступа:
Sadovskaya, O.V.; Садовская, Оксана Викторовна; Sadovskii, V.M.; Садовский, Владимир Михайлович

[Text] / N. Rubab [et al.] // Phys. Plasmas. - 2010. - Vol. 17, Is. 10. - Ст. 103704, DOI 10.1063/1.3491336. - Cited References: 54. - This work is funded by the Higher Education Commission of Pakistan under the HEC-Overseas scholarship program Grant No. Ref: 1-1/PM OS /Phase-II/Batch-I/Austria/2007/. Part of this work was done while N. V. Erkaev was at the Space Research Institute of the Austrian Academy of Sciences in Graz. This work is also supported due to the RFBR Grant No. 09-05-91000-ANF-a. Further support is due to the "Austrian Fonds zur Forderung der Wissenschaftlichen Forschung" under Grant No. P20145-N16. . - ISSN 1070-664XРУБ Physics, Fluids & Plasmas

Аннотация: This study presents a theoretical approach to analyze the influence of kappa distributed streaming ions and magnetized electrons on the plasma wave propagation in the presence of dust by employing two-potential theory. In particular, analytical expressions under certain conditions are derived for various modes of propagation comprising of kinetic Alfven wave streaming instability, two stream instability, and dust acoustic and whistler waves. A dispersion relation for kinetic Alfven-like streaming instability has been derived. The effects of dust particles and Lorentzian index on the growth rates and the threshold streaming velocity for the excitation of the instability are examined. The streaming velocity is observed to be destabilizing for slow motion and stabilizing for fast streaming motions. It is also observed that the presence of magnetic field and superthermal particles hinders the growth rate of instability. Possible applications to various space and astrophysical situations are discussed. (C) 2010 American Institute of Physics. [doi:10.1063/1.3491336]


Доп.точки доступа:
Rubab, N.; Erkaev, N.V.; Еркаев, Николай Васильевич; Langmayr, D.; Biernat, H.K.

[Text] / N.V. Erkaev, V.S. Semenov, H.K. Biernat // Phys. Plasmas. - 2010. - Vol. 17, Is. 6. - Ст. 60703, DOI 10.1063/1.3439687. - Cited References: 15. - This work is supported by RFBR (Grant Nos. N 07-05-00776-a and N 09-05-91000-ANF_a), and by Program No. 16 of RAS. Additional support is due to the Austrian "Fonds zur Forderung der wissenschaftlichen Forschung" under Project No. I 193-N16 and the "Verwaltungsstelle fur Auslandsbeziehungen" of the Austrian Academy of Sciences. . - ISSN 1070-664XРУБ Physics, Fluids & Plasmas

Аннотация: Hall magnetohydrodynamic model is investigated for current sheet flapping oscillations, which implies a gradient of the normal magnetic field component. For the initial undisturbed current sheet structure, the normal magnetic field component is assumed to have a weak linear variation. The profile of the electric current velocity is described by hyperbolic functions with a maximum at the center of the current sheet. In the framework of this model, eigenfrequencies are calculated as functions of the wave number for the "kink" and "sausage" flapping wave modes. Because of the Hall effects, the flapping eigenfrequency is larger for the waves propagating along the electric current, and it is smaller for the opposite wave propagation with respect to the current. The asymmetry of the flapping wave propagation, caused by Hall effects, is pronounced stronger for thinner current sheets. This is due to the Doppler effect related to the electric current velocity. (C) 2010 American Institute of Physics. [doi:10.1063/1.3439687]


Доп.точки доступа:
Erkaev, N.V.; Еркаев, Николай Васильевич; Semenov, V.S.; Biernat, H.K.

/ V. M. Sadovskii // Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics). - 2013. - Vol. 8236 LNCS: 5th International Conference on Numerical Analysis and Applications, NAA 2012 (15 June 2013 through 20 June 2013, Lozenetz. - P479-486, DOI 10.1007/978-3-642-41515-9_54 . -
Аннотация: Mathematical models of the dynamics of elastic-plastic and granular media are formulated as variational inequalities for hyperbolic operators with one-sided constraints describing the transition of a material in plastic state. On this basis a priori integral estimates are constructed in characteristic cones of operators, from which follows the uniqueness and continuous dependence on initial data of solutions of the Cauchy problem and of the boundary-value problems with dissipative boundary conditions. With the help of an integral generalization of variational inequalities the relationships of strong discontinuity in dynamic models of elastic-plastic and granular media are obtained, whose analysis allows us to calculate velocities of shock waves and to construct discontinuous solutions. Original algorithms of solution correction are developed which can be considered as a realization of the splitting method with respect to physical processes. В© 2013 Springer-Verlag.

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Доп.точки доступа:
Sadovskii, V.M.; Садовский, Владимир Михайлович

[Текст] : статья / V. M. Sadovskii, O. V. Sadovskaya, K. S. Svobodina // Journal of Siberian Federal University. Mathematics & Physics. - 2013. - Vol. 6, Iss. 3. - p. 342-348
   Перевод заглавия: Анализ дисперсии гидроакустических волн на основе модели вязкоупругой среды
Аннотация: On the basis of mathematical model of the Poynting–Thomson viscoelastic medium the effect of acoustic dispersion of water is described: the phase velocity of waves of terahertz frequency is doubled in comparison with the velocity of waves of sound range. Rheological parameters of the model are selected by means of the values of the velocities of propagation of slow and fast monochromatic waves. The system of equations of the dynamics of the Poynting–Thomson viscoelastic medium is reduced to the form, hyperbolic by Friedrichs. It guarantees the correctness of the Cauchy problem and boundary value problems with dissipative boundary conditions, and also allows to use the monotone grid-characteristic schemes for numerical solution of problems. In the framework of 1D model the computations of a transformation of hydroacoustic waves, generated by U-shaped impulse of pressure, were performed. Results of computations show a strong damping of the fast precursor as it passes the distance of hundred nanometers from the moment of entry and the emergence of stable profile of the slow wave at the mesolevel.

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Sadovskaya, O.V.; Садовская, Оксана Викторовна; Svobodina, K.S.; Садовский, Владимир Михайлович

/ V. M. Sadovskii, O. V. Sadovskaya // Physical Mesomechanics. - 2013. - Vol. 16, № 4. - P312-318, DOI 10.1134/S102995991304005X . - ISSN 1029-9599
Аннотация: Based on dynamic equations of a heterogeneous elastic medium which take into account rotational degrees of freedom of microstructure particles, a simplified mathematical model was constructed to describe the wave motions of a nematic liquid crystal under weak mechanical and temperature perturbations. It is shown that in the medium under plane deformation, the tangential stress obeys the Klein-Gordon equation of oscillatory particle rotation. Consideration is given to the possibility of initiating rotational waves in a nematic liquid crystal, which change its optical properties, due to heat sources acting at its boundary. © 2013 Pleiades Publishing, Ltd.

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ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44

Доп.точки доступа:
Sadovskaya, O.V.; Садовская, Оксана Викторовна; Sadovsky V.M.

[Text] / H. Gunell [et al.] // Plasma Phys. Control. Fusion. - 2008. - Vol. 50, Is. 7. - Ст. 74018, DOI 10.1088/0741-3335/50/7/074018. - Cited References: 27 . - ISSN 0741-3335РУБ Physics, Fluids & Plasmas + Physics, Nuclear

Аннотация: We present measurements of oscillations in the electron density, ion density and ion velocity in the induced magnetosphere of Mars. The fundamental frequency of the oscillations is a few millihertz, but higher harmonics are present in the spectrum. The oscillations are observed in a region where there is a velocity shear in the plasma flow. The fundamental frequency is in agreement with computational results from an ideal-MHD model. An interpretation based on velocity-shear instabilities is described.


Доп.точки доступа:
Gunell, H.; Amerstorfer, U.V.; Nilsson, H.; Grima, C.; Koepke, M.; Franz, M.; Winningham, J.D.; Frahm, R.A.; Sauvaud, J.A.; Fedorov, A.; Erkaev, N.V.; Еркаев, Николай Васильевич; Biernat, H.K.; Holmstrom, M.; Lundin, R.; Barabash, S.

[Text] / N. V. Erkaev, V. S. Semenov, H. K. Biernat // Geophys. Res. Lett. - 2008. - Vol. 35, Is. 2. - Ст. L02111, DOI 10.1029/2007GL032277. - Cited References: 13 . - ISSN 0094-8276РУБ Geosciences, Multidisciplinary

Аннотация: A new kind of magnetohydrodynamic waves are analyzed for a current sheet in a presence of a small normal magnetic field component varying along the sheet. As a background, two simplified models of a current sheet are considered with a uniform and nonuniform current distributions in the current sheet. On a basis of these two models, the flapping-type waves are obtained which are related to a coexistence of two gradients of the tangential and normal magnetic field components along the normal and tangential directions with respect to the current sheet. A stable situation for the current sheet is associated with a positive result of the multiplication of the two magnetic gradients, and unstable ( wave growth) condition corresponds to a negative result of the product. In the stable region, the "kink''-like wave mode is interpreted as so called flapping waves observed in the Earth's magnetotail current sheet.


Доп.точки доступа:
Erkaev, N.V.; Еркаев, Николай Васильевич; Semenov, V.S.; Biernat, H.K.

[Text] / N. V. Erkaev, V. S. Semenov, H. K. Biernat // Phys. Rev. Lett. - 2007. - Vol. 99, Is. 23. - Ст. 235003, DOI 10.1103/PhysRevLett.99.235003. - Cited References: 10 . - ISSN 0031-9007РУБ Physics, Multidisciplinary

Аннотация: A new kind of magnetohydrodynamic instability and waves are analyzed for a current sheet in the presence of a small normal magnetic field component varying along the sheet. These waves and instability are related to the existence of two gradients of the tangential (B(tau)) and normal (B(n)) magnetic field components along the normal (del(n)B(tau)) and tangential (del(tau)B(n)) directions with respect to the current sheet. The current sheet can be stable or unstable if the multiplication of two magnetic gradients is positive or negative. In the stable region, the kinklike wave mode is interpreted as so-called flapping waves observed in Earth's magnetotail current sheet. The kink wave group velocity estimated for the Earth's current sheet is of the order of a few tens of kilometers per second. This is in good agreement with the observations of the flapping motions of the magnetotail current sheet.


Доп.точки доступа:
Erkaev, N.V.; Еркаев, Николай Васильевич; Semenov, V.S.; Biernat, H.K.

[Text] / N. V. Erkaev [et al.] // Astrophys. J. Suppl. Ser. - 2005. - Vol. 157, Is. 2. - P396-401, DOI 10.1086/427904. - Cited References: 48 . - ISSN 0067-0049РУБ Astronomy & Astrophysics

Аннотация: During the past years, more than 130 giant planets were discovered in extrasolar planetary systems. Because of the fact that the orbital distances are very close to their host stars, these planets are embedded in a dense stellar wind, which can pick up planetary ions. We model the stellar wind interaction of the short-periodic exoplanets OGLE-TR-56b and HD 209458b at their orbital distances of approximate to 0.023 AU and approximate to 0.045 AU, by calculating the Alfven Mach number and the magnetosonic Mach number in the stellar wind plasma flow. We then analyze the different plasma interaction regimes around the planetary obstacles, which appear for different stellar wind parameters. Our study shows that the stellar wind plasma parameters like temperature, interplanetary magnetic field, particle density, and velocity near planetary obstacles at orbital distances closer than 0.1-0.2 AU have conditions such that no bow shocks evolve. Our study shows also that these close-in exoplanets are in a submagnetosonic regime comparable to the magnetospheric plasma interaction of the inner satellites of Jupiter and Saturn. Furthermore, we compare the results achieved for both exoplanets with the Jupiter-class exoplanet HD 28185b at its orbital distance of approximate to 1.03 AU. Finally, we also discuss the behavior of the stellar wind plasma flow close to the planetary obstacles of two highly eccentric gas giants, namely, HD 108147b and HD 162020b. Because of their eccentric orbits, these two exoplanets periodically experience both regimes with and without a bow shock. Finally, we simulate the neutral gas density of HD 209458b with a Monte Carlo model. By using the plasma parameters obtained in our study we calculate the ion production and loss rate of H+ with a test particle model. Our simulations yield H+ loss rates for HD 209458b or similar giant exoplanets in orders of about 10(8)-10(9) g s(-1). These ion loss rates are at least 1 order of magnitude lower than the observed loss rate of evaporating neutral H atoms. Our study indicates, that similar gas giants at larger orbital distances have lower ion loss rates. Thus, the dominating component of particle loss of short-periodic Jupiter-class exoplanets will be neutral hydrogen.


Доп.точки доступа:
Erkaev, N.V.; Еркаев, Николай Васильевич; Penz, T.; Lammer, H.; Lichtenegger, H.I.M.; Biernat, H.K.; Wurz, P.; Griessmeier, J.M.; Weiss, W.W.

[Text] / N. V. Erkaev [et al.] // Phys. Plasmas. - 2005. - Vol. 12, Is. 1. - Ст. 12905, DOI 10.1063/1.1833392. - Cited References: 18 . - ISSN 1070-664XРУБ Physics, Fluids & Plasmas

Аннотация: Within the framework of the assumption of large azimuthal wave numbers, the equations for Alfven and slow magnetosonic waves are obtained using frozen-in material coordinates. These equations are specified for the case of a nonuniform magnetic field with axial symmetry. Assuming a meridional polarization of the magnetic field and velocity perturbations, the effects of Alfven wave propagation are analyzed which are related to geometric characteristics of a nonuniform magnetic field: (a) A finite curvature radius of the magnetic field lines and (b) convergence of magnetic field lines. The interaction between the Alfven and magnetosonic waves is found to be strongly dependent on the curvature radius of the magnetic tube and the local plasma beta parameter. The electric field amplitude and the length scale of a wave front are found to increase very strongly in the course of the Alfven wave propagation along a converging magnetic flux tube. Also studied is a temporal decrease of the wave perturbations which is caused by dissipation at the conducting boundary. (C) 2005 American Institute of Physics.


Доп.точки доступа:
Erkaev, N.V.; Еркаев, Николай Васильевич; Shaidurov, V.A.; Semenov, V.S.; Langmayr, D.; Biernat, H.K.