Труды сотрудников ИВМ СО РАН

[Text] : статья / V.V. Denisenko // Siberian mathematical journal. - 2011. - Vol. 52, № 2. - p. 207-221DOI 10.1134/S0037446611020030 . -
Аннотация: We propose some minimum principle for an energy functional in an elliptic boundary value problem that arises in constructing time-harmonic solutions to the Maxwell equations. We suggest the potentials other than the vector and scalar potentials, used in the mathematical modeling of electromagnetic fields since the operators of traditional problems are not sign definite, which complicates constructions of iterative solution methods. We consider the problem in a parallelepiped whose boundary is ideally conducting. For nonresonant frequencies we prove that the operator of the boundary value problem is positive definite, propose a minimum principle for a quadratic energy functional, and prove the existence and uniqueness of generalized solutions.

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

Доп.точки доступа:
Денисенко, Валерий Васильевич

[Text] : статья / N.V. Erkaev, V.S. Semenov, H.K. Biernat // Nonlinear Processes in Geophysics. - 2002. - Vol. 9, № 2. - p. 131–138 . - ISSN 1023-5809
Аннотация: Magnetic reconnection is an important process providing a fast conversion of magnetic energy into thermal and kinetic plasma energy. In this concern, a key problem is that of the resistive diffusion region where the reconnec-tion process is initiated. In this paper, the diffusion region is associated with a nonuniform conductivity localized to a small region. The nonsteady resistive incompressible MHD equations are solved numerically for the case of symmetric reconnection of antiparallel magnetic fields. A Petschek type steady-state solution is obtained as a result of time relax-ation of the reconnection layer structure from an arbitrary initial stage. The structure of the diffusion region is studied for various ratios of maximum and minimum values of the plasma resistivity. The effective length of the diffusion re-gion and the reconnection rate are determined as functions of the length scale and the maximum of the resistivity. For suf-ficiently small length scale of the resistivity, the reconnection rate is shown to be consistent with Petschek's formula. By increasing the resistivity length scale and decreasing the re-sistivity maximum, the reconnection layer tends to be wider, and correspondingly, the reconnection rate tends to be more consistent with that of the Parker-Sweet regime.

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

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

/ D.B. Korovinskiy [et al.] // J. Geophys. Res-Space Phys. - 2013. - Vol. 118, Is. 3. - P1146-1158, DOI 10.1002/jgra.50206. - Cited References: 39. - This work is supported by the Austrian Science Fund (FWF): I193-N16, by the Onderzoekfonds KU Leuven (Research Fund KU Leuven), by RFBR Grants 12-05-00918-a and 12-05-00152-a, and by SPSU Grants 11.38.47.2011 and 11.38.84.2012. The research has received funding also from the European Union Seventh Framework Programme [FP7/2007-2013] under grant agreement 269198-Geoplasmas (Marie Curie International Research Staff Exchange Scheme) and 218816 (SOTERIA project). The simulations were conducted on the resources of the Vlaams Supercomputer Centrum (VSC) at the Katholieke Universiteit Leuven. N.V.E., V.S.S. and D.B.K. thank also ISSI for hospitality and financial support. The authors thank reviewers for their comments, which gave us the substantial aid in preparing of this manuscript. . - 13. - ISSN 2169-9380РУБ Astronomy & Astrophysics

Аннотация: The paper presents the detailed numerical investigation of the "double-gradient mode," which is believed to be responsible for the magnetotail flapping oscillations-the fast vertical (normal to the layer) oscillations of the Earth's magnetotail plasma sheet with a quasiperiod similar to 100-200 s. The instability is studied using the magnetotail near-equilibrium configuration. For the first time, linear three-dimensional numerical analysis is complemented with full 3-D MHD simulations. It is known that the "double-gradient mode" has unstable solutions in the region of the tailward growth of the magnetic field component, normal to the current sheet. The unstable kink branch of the mode is the focus of our study. Linear MHD code results agree with the theory, and the growth rate is found to be close to the peak value, provided by the analytical estimates. Full 3-D simulations are initialized with the numerically relaxed magnetotail equilibrium, similar to the linear code initial condition. The calculations show that current layer with tailward gradient of the normal component of the magnetic field is unstable to wavelengths longer than the curvature radius of the field line. The segment of the current sheet with the earthward gradient of the normal component makes some stabilizing effect (the same effect is registered in the linearized MHD simulations) due to the minimum of the total pressure localized in the center of the sheet. The overall growth rate is close to the theoretical double-gradient estimate averaged over the computational domain.

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Доп.точки доступа:
Korovinskiy, D.B.; Divin, A.; Erkaev, N.V.; Еркаев, Николай Васильевич; Ivanova, V.V.; Ivanov, I.B.; Semenov, V.S.; Lapenta, G.; Markidis, S.; Biernat, H.K.; Zellinger, M.

[Text] : статья / V.V.Denisenko // Computational Research. - 2013. - Vol. 1, № 2. - p. 34 - 51DOI 10.13189/cr.2013.010203 . -
Аннотация: Conventional two dimensional model for electric fields in the Earth’s ionosphere is analyzed to estimate its error. The main difficulties arise due to asymmetry of the conductivity tensor. We use the energy method and small parameter expansion. To make it possible in spite of asymmetry of the tensor coefficients the problem is reduced to the problem of minimum of proper quadratic energy functional. The variational principle is stated and proved for the 3-D boundary value problem. The error of the 2-D approximation is analyzed in the case, when conductor occupies a flat layer 0 < z < z0 and is homogeneous in z direction, and the vector of magnetic field has only z component. The results of numerical simulation of the electric field penetration from ground to the Earth’s ionosphere with reduction of the 3-D model of the ionospheric conductor to the 2-D model are presented. Precision of such an approach is demonstrated.

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

Доп.точки доступа:
Денисенко, Валерий Васильевич

/ C. J. Farrugia [et al.] // Sol. Phys. - 2012. - Vol. 281, Is. 1. - pp. 461-489, DOI 10.1007/s11207-012-0119-1. - Cited References: 53 . - 29. - ISSN 0038-0938РУБ Astronomy & Astrophysics

Аннотация: We discuss the temporal variations and frequency distributions of solar wind and interplanetary magnetic field parameters during the solar minimum of 2007-2009 from measurements returned by the IMPACT and PLASTIC instruments on STEREO-A. We find that the density and total field strength were significantly weaker than in the previous minimum. The Alfv,n Mach number was higher than typical. This reflects the weakness of magnetohydrodynamic (MHD) forces, and has a direct effect on the solar wind-magnetosphere interactions. We then discuss two major aspects that this weak solar activity had on the magnetosphere, using data from Wind and ground-based observations: i) the dayside contribution to the cross-polar cap potential (CPCP), and ii) the shapes of the magnetopause and bow shock. For i) we find a low interplanetary electric field of 1.3 +/- 0.9 mV m(-1) and a CPCP of 37.3 +/- 20.2 kV. The auroral activity is closely correlated to the prevalent stream-stream interactions. We suggest that the Alfven wave trains in the fast streams and Kelvin-Helmholtz instability were the predominant agents mediating the transfer of solar wind momentum and energy to the magnetosphere during this three-year period. For ii) we determine 328 magnetopause and 271 bow shock crossings made by Geotail, Cluster 1, and the THEMIS B and C spacecraft during a three-month interval when the daily averages of the magnetic and kinetic energy densities attained their lowest value during the three years under survey. We use the same numerical approach as in Fairfield's (J. Geophys. Res. 76, 7600, 1971) empirical model and compare our findings with three magnetopause models. The stand-off distance of the subsolar magnetopause and bow shock were 11.8 R-E and 14.35 R-E, respectively. When comparing with Fairfield's (1971) classic result, we find that the subsolar magnetosheath is thinner by similar to 1 R-E. This is mainly due to the low dynamic pressure which results in a sunward shift of the magnetopause. The magnetopause is more flared than in Fairfield's model. By contrast the bow shock is less flared, and the latter is the result of weaker MHD forces.

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Farrugia, C.J.; Harris, B.; Leitner, M.; Mostl, C.; Galvin, A.B.; Simunac, K.D.C.; Torbert, R.B.; Temmer, M.B.; Veronig, A.M.; Erkaev, N.V.; Еркаев, Николай Васильевич; Szabo, A.; Ogilvie, K.W.; Luhmann, J.G.; Osherovich, V.A.

/ 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] / U. Taubenschuss [et al.] // Ann. Geophys. - 2010. - Vol. 28, Is. 5. - pp. 1075-1100, DOI 10.5194/angeo-28-1075-2010. - Cited References: 92. - The author appreciates financial support on behalf of the projects 06/9690 from the Austrian Research Community and A3-12T63/2007-1 from the Styrian government. Participation at the ISSS8 was made possible due to the travel fellowship of UCLA. Nikolai Erkaev acknowledges support by RFBR grants Nos. 07-05-00135 and 09-05-91000-ANF. Charles Farrugia received NASA grants NNG06GD41G and NNX08AD11G. Christian Mostl and Ute Amerstorfer work under FWF projects P20145N16 and P21051-N16 of the Austrian Science Foundation, respectively. . - ISSN 0992-7689РУБ Astronomy & Astrophysics + Geosciences, Multidisciplinary + Meteorology & Atmospheric Sciences

Аннотация: We investigate the propagation of magnetic clouds (MCs) through the inner heliosphere using 2.5-D ideal magnetohydrodynamic (MHD) simulations. A numerical solution is obtained on a spherical grid, either in a meridional plane or in an equatorial plane, by using a Roe-type approximate Riemann solver in the frame of a finite volume approach. The structured background solar wind is simulated for a solar activity minimum phase. In the frame of MC propagation, special emphasis is placed on the role of the initial magnetic handedness of the MC's force-free magnetic field because this parameter strongly influences the efficiency of magnetic reconnection between the MC's magnetic field and the interplanetary magnetic field. Magnetic clouds with an axis oriented perpendicular to the equatorial plane develop into an elliptic shape, and the ellipse drifts into azimuthal direction. A new feature seen in our simulations is an additional tilt of the ellipse with respect to the direction of propagation as a direct consequence of magnetic reconnection. During propagation in a meridional plane, the initial circular cross section develops a concave-outward shape. Depending on the initial handedness, the cloud's magnetic field may reconnect along its backside flanks to the ambient interplanetary magnetic field (IMF), thereby losing magnetic flux to the IMF. Such a process in combination with a structured ambient solar wind has never been analyzed in detail before. Furthermore, we address the topics of force-free magnetic field conservation and the development of equatorward flows ahead of a concave-outward shaped MC. Detailed profiles are presented for the radial evolution of magnetoplasma and geometrical parameters. The principal features seen in our MHD simulations are in good agreement with in-situ measurements performed by spacecraft. The 2.5-D studies presented here may serve as a basis under more simple geometrical conditions to understand more complicated effects seen in 3-D simulations.


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

[Текст] : статья / S. Ahnert, T. Fink, A. Zinovyev // Journal of Theoretical Biology. - 2008. - Vol. 252, Iss. 4. - p. 587–592DOI 10.1016/j.jtbi.2008.02.005 . -
Аннотация: Despite tremendous advances in the field of genomics, the amount and function of the large non-coding part of the genome in higher organisms remains poorly understood. Here we report an observation, made for 37 fully sequenced eukaryotic genomes, which indicates that eukaryotes require a certain minimum amount of non-coding DNA (ncDNA). This minimum increases quadratically with the amount of DNA located in exons. Based on a simple model of the growth of regulatory networks, we derive a theoretical prediction of the required quantity of ncDNA and find it to be in excellent agreement with the data. The amount of additional ncDNA (in basepairs) which eukaryotes require obeys Ndef=1/2 (Nc/Np) (Nc−Np), where Nc is the amount of exonic DNA, and Np is a constant of about 10 Mb. This value Ndef corresponds to a few percent of the genome in Homo sapiens and other mammals, and up to half the genome in simpler eukaryotes. Thus, our findings confirm that eukaryotic life depends on a substantial fraction of ncDNA and also make a prediction of the size of this fraction, which matches the data closely.

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Доп.точки доступа:
Fink, Thomas M.A.; Zinovyev, Andrei; Зиновьев, Андрей Юрьевич

[Text] / H. K. Biernat [et al.] // Planet Space Sci. - 2007. - Vol. 55, Is. 12. - P1793-1803, DOI 10.1016/j.pss.2007.01.006. - Cited References: 28 . - ISSN 0032-0633РУБ Astronomy & Astrophysics

Аннотация: In this paper, the solar wind flow around Venus is modeled as a nondissipative fluid which obeys the ideal magnetohydrodynamic equations extended for mass loading processes. The mass loading parameter is calculated for four different cases, corresponding to solar minimum and maximum XUV flux and to nominal and low solar wind velocity. We get smooth profiles of the field and plasma parameters in the magnetosheath. Based on the results of this flow model, we investigate the occurrence of the Kelvin-Helmholtz (K-H) instability at the equatorial flanks of the ionopause of Venus. By comparing the instability growth time with the propagation time of the K-H wave, we find that the K-H instability can evolve at the ionopause for all four solar wind conditions. (C) 2007 Elsevier Ltd. All rights reserved.


Доп.точки доступа:
Biernat, H.K.; Erkaev, N.V.; Еркаев, Николай Васильевич; Amerstorfer, U.V.; Penz, T.; Lichtenegger, H.I.M.

[Text] / H. . Lammer [et al.] // Astrobiology. - 2007. - Vol. 7, Is. 1. - P185-207, DOI 10.1089/ast.2006.0128. - Cited References: 104 . - ISSN 1531-1074РУБ Astronomy & Astrophysics + Biology + Geosciences, Multidisciplinary

Аннотация: Atmospheric erosion Of CO2-rich Earth-size exoplanets due to coronal mass ejection (CME)-induced ion pick up within close-in habitable zones of active M-type dwarf stars is investigated. Since M stars are active at the X-ray and extreme ultraviolet radiation (XUV) wavelengths over long periods of time, we have applied a thermal balance model at various XUV flux input values for simulating the thermospheric heating by photodissociation and ionization processes due to exothermic chemical reactions and cooling by the CO2 infrared radiation in the 15 mu m band. Our study shows that intense XUV radiation of active M stars results in atmospheric expansion and extended exospheres. Using thermospheric neutral and ion densities calculated for various XUV fluxes, we applied a numerical test particle model for simulation of atmospheric ion pick up loss from an extended exosphere arising from its interaction with expected minimum and maximum CME plasma flows. Our results indicate that the Earth-like exoplanets that have no, or weak, magnetic moments may lose tens to hundreds of bars of atmospheric pressure, or even their whole atmospheres due to the CME-induced O+ ion pick up at orbital distances <= 0.2 astronomical units. We have found that, when exposed to intense XUV fluxes, atmospheres with CO2/N-2 mixing ratios lower than 96% will show an increase in exospheric temperatures and expanded thermosphere-exosphere environments. Hence, they suffer stronger atmospheric erosion, which can result in the total loss of several hundred bars even if an exoplanet is protected by a "magnetic shield" with its boundary located at I Earth radius above the surface. Furthermore, our study indicates that magnetic moments of tidally locked Earth-like exoplanets are essential for protecting their expanded upper atmospheres because of intense XUV radiation against CME plasma erosion. Therefore, we suggest that larger and more massive terrestrial-type exoplanets may better protect their atmospheres against CMEs, because the larger cores of such exoplanets would generate stronger magnetic moments and their higher gravitational acceleration would constrain the expansion of their thermosphere-exosphere regions and reduce atmospheric escape.


Доп.точки доступа:
Lammer, H.; Lichtenegger, H.I.M.; Kulikov, Y.N.; Griessmeier, J.M.; Terada, N.; Erkaev, N.V.; Еркаев, Николай Васильевич; Biernat, H.K.; Khodachenko, M.L.; Ribas, I.; Penz, T.; Selsis, F.

[Text] / H. Gunell [et al.] // Planet Space Sci. - 2005. - Vol. 53, Is. 4. - P433-441, DOI 10.1016/j.pss.2004.07.021. - Cited References: 21 . - ISSN 0032-0633РУБ Astronomy & Astrophysics

Аннотация: We present simulated images of energetic neutral atoms (ENAs) produced in charge exchange collisions between solar wind protons and neutral atoms in the exosphere of Venus, and make a comparison with earlier results for Mars. The images are found to be dominated by two local maxima. One produced by charge exchange collisions in the solar wind, upstream of the bow shock, and the other close to the dayside ionopause. The simulated ENA fluxes at Venus are lower than those obtained in similar simulations of ENA images at Mars at solar minimum conditions, and close to the fluxes at Mars at solar maximum. Our numerical study shows that the ENA flux decreases with an increasing ionopause altitude. The influence of the Venus nighttime hydrogen bulge on the ENA emission is small. (C) 2004 Elsevier Ltd. All rights reserved.


Доп.точки доступа:
Gunell, H.; Holmstrom, M.; Biernat, H.K.; Erkaev, N.V.; Еркаев, Николай Васильевич

[Text] / V. V. Denisenko, S. S. Zamai, A. V. Kitaev // Geomagn. Aeron. - 2003. - Vol. 43, Is. 6. - P680-686. - Cited References: 15 . - ISSN 0016-7932РУБ Geochemistry & Geophysics

Аннотация: The effect of viscous friction at the boundary between the plasma sheet and the solar wind on electric field generation in the plasma sheet is estimated. The boundary layer is modeled by a viscous layer with two mixing plasma flows. The distribution of the flow velocity in the inner parts of the plasma sheet outside the boundary layer is specified on the basis of experimental data. The calculated distribution of the electric potential in the plasma sheet and at the magnetopause is projected along magnetic lines onto the ionosphere. It has been indicated that, within the scope of the adopted model, viscous friction on the magnetotail flanks for an effective Reynolds number of Re = 3 x 10(3) results in an increase in the potential across the polar cap from 11 to 18 kV. In this case the maximum and minimum of the electric potential at the polar cap boundary are shifted from the nightside to the dayside. It is emphasized that the total distribution of the electric potential in the polar cap under quiet conditions results from the operation of several mechanisms of electric field generation.


Доп.точки доступа:
Zamai, S.S.; Kitaev, A.V.; Денисенко, Валерий Васильевич

[Text] : статья / A. N. Gorban [et al.] // Bulletin of Mathematical Biology. - 2011. - Vol. 73, Iss. 9. - p. 2013-2044DOI 10.1007/s11538-010-9597-1 . -
Аннотация: The “Law of the Minimum” states that growth is controlled by the scarcest resource (limiting factor). This concept was originally applied to plant or crop growth (Justus von Liebig, 1840, Salisbury, Plant physiology, 4th edn., Wadsworth, Belmont, 1992) and quantitatively supported by many experiments. Some generalizations based on more complicated “dose-response” curves were proposed. Violations of this law in natural and experimental ecosystems were also reported. We study models of adaptation in ensembles of similar organisms under load of environmental factors and prove that violation of Liebig’s law follows from adaptation effects. If the fitness of an organism in a fixed environment satisfies the Law of the Minimum then adaptation equalizes the pressure of essential factors and, therefore, acts against the Liebig’s law. This is the the Law of the Minimum paradox: if for a randomly chosen pair “organism–environment” the Law of the Minimum typically holds, then in a well-adapted system, we have to expect violations of this law. For the opposite interaction of factors (a synergistic system of factors which amplify each other), adaptation leads from factor equivalence to limitations by a smaller number of factors. For analysis of adaptation, we develop a system of models based on Selye’s idea of the universal adaptation resource (adaptation energy). These models predict that under the load of an environmental factor a population separates into two groups (phases): a less correlated, well adapted group and a highly correlated group with a larger variance of attributes, which experiences problems with adaptation. Some empirical data are presented and evidences of interdisciplinary applications to econometrics are discussed.

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Gorban, A.N.; Горбань, Александр Николаевич; Pokidysheva, L.I.; Smirnova, E.V.; Tyukina, T.A.

[Text] / Y. V. NEMIROVSKII, V. M. NEBOGATOV // SOVIET APPLIED MECHANICS. - 1986. - Vol. 22, Is. 11. - P1098-1103, DOI 10.1007/BF01272878. - Cited References: 6 . - ISSN 0038-5298РУБ Mechanics


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Держатели документа:
ACAD SCI USSR,CTR COMPUTAT,KRASNOYARSK,USSR
ИВМ СО РАН
Доп.точки доступа:
NEMIROVSKII, Y.V.; NEBOGATOV, V.M.

/ V. A. Gerasimov, B. S. Dobronets, M. Yu. Shustrov // Avtomatika i Telemekhanika. - 1991. - Is. 2. - P83-88 . - ISSN 0005-2310
Аннотация: Main principles of numerical arithmetical operations on histograms of random values are considered. A set of operations is defined including summing, subtracting, multiplication, division, rising to an integer power, maximum, and minimum. It is stated that this set is sufficient to calculate any function of an independent random value. A PASCAL program package is introduced implementing histogram arithmetic. Several applications of the package are mentioned.

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Держатели документа:
Vychislitel'nyj Tsentr Sibirskogo, Otdeleniya AN SSSR, Krasnoyarsk, Russian Federation
ИВМ СО РАН

Доп.точки доступа:
Gerasimov, V.A.; Dobronets, B.S.; Добронец, Борис Станиславович; Shustrov, M.Yu.

[Text] / V. V. Denissenko // ENUMATH 97 - 2ND EUROPEAN CONFERENCE ON NUMERICAL MATHEMATICS AND ADVANCED APPLICATIONS : WORLD SCIENTIFIC PUBL CO PTE LTD, 1998. - 2nd European Conference on Numerical Mathematics and Advanced Applications (SEP 28-OCT 03, 1997, HEIDELBERG, GERMANY). - P262-269. - Cited References: 6 . - ISBN 981-02-3546-1РУБ Mathematics

Аннотация: Dirichlet's and Thompson's variational methods that are in wide use to estimate electric capacitance values are generalized for transfer process with nonsymmetrical coefficients. In restating the problem the operator of the boundary value problem of elliptic type is a symmetrical positive definite operator. A quadratic energy functional which attains minimum at the solution of the boundary value problem is formulated and proved. It is used to estimate the linear functional value. The multigrid method is used to obtain guaranteed precise estimates for a test problem.

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Держатели документа:
Russian Acad Sci, Inst Computat Modelling, Krasnoyarsk 660036, Russia
ИВМ СО РАН

Доп.точки доступа:
Denisenko, V.V.; Денисенко, Валерий Васильевич

/ A. Shevyrnogov, G. Vysotskaya, E. Shevyrnogov // Advances in Space Research. - 2004. - Vol. 33, Is. 7. - P. 1179-1183, DOI 10.1016/S0273-1177(03)00369-7 . - ISSN 0273-1177
Аннотация: The work presents the data on the spatial distribution of temperature anomalies in the Global Ocean, based on the long-term measurements with the AVHRR satellite equipment. It is noteworthy that such results can be only obtained by using long time series of satellite images. To obtain them by ship-borne methods is actually impossible. The proposed anomaly criterion is equal to a difference between minimum/maximum and average temperature, normed for the mean square deviation. The difference is calculated from the whole time series (with regard to a season). Based on this criterion, anomalies can be distinguished on the background of usual seasonal dynamics at various absolute values of deviations of the measured parameter. Besides, rare, single, fluctuations can be also revealed. Based on the proposed criterion, connected zones have been defined. These zones occur almost in every part of the Global Ocean. The data obtained have been analyzed in association with the CZCS (1978-1986) and SeaWiFS satellite images in order to compare them with the areas of anomalous dynamics of chlorophyll concentration and the regions quasistationary in the seasonal dynamics of chlorophyll. Anomalies in the temperature dynamics are of exceptional importance for the formation of climatic deviations; they affect the ocean-atmosphere interaction and reflect variations in the hydrological structure of the surface waters. The work presents a comparison with the dynamics of chlorophyll concentration distribution determined from the SeaWiFS data for the Atlantic Ocean. В© 2003 COSPAR. Published by Elsevier Ltd. All rights reserved.

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Shevyrnogov, A.; Vysotskaya, G.; Высоцкая, Галина Степановна; Shevyrnogov, E.

/ D. Kubyshkina [et al.] // Adv. Space Res. - 2015. - Vol. 56, Is. 8. - P1699-1706, DOI 10.1016/j.asr.2015.07.023 . - ISSN 0273-1177
Аннотация: We study the dependence of the flapping oscillations on the magnetotail current sheet bending, which is caused by the dipole tilt. Observations show that flapping waves propagate from the center of the current sheet to its flanks with a velocity one order of magnitude less than typical Alfven speed. For our analysis we use the double gradient model (Erkaev et al., 2009) of the flapping oscillations, which predicts a small minimum of the total pressure (gas plus magnetic) across the current layer. It is the depth of the potential well in the total pressure which defines the period and the speed of the flapping waves. Using the extension of the Kan/Manankova equilibriums for the non-zero dipole tilt we investigate the depth of the potential well with respect to the current sheet bending rate. We show that with the growth of the dipole tilt angle the depth of the potential well becomes smaller, the period of the flapping oscillations increases, and oscillations become nonlinear. There exists the critical tilt angle, where the potential well disappears and flapping regime changes from oscillations to instability. © 2015 COSPAR. Published by Elsevier Ltd. All rights reserved.

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Держатели документа:
Saint Petersburg State University, Saint-Petersburg, Russian Federation
Institute of Computational Modelling SB RAS, Krasnoyarsk, Russian Federation
Siberian Federal University, Krasnoyarsk, Russian Federation; Siberian Federal University, Krasnoyarsk, Russian Federation

Доп.точки доступа:
Kubyshkina, D.; Semenov, V.; Erkaev, N.V.; Еркаев, Николай Васильевич; Kubyshkin, I.

/ I. V. Zenkov, I. M. Baradulin // Gorn. Zh. - 2016. - Vol. 2016, Is. 3. - С. 85-88, DOI 10.17580/gzh.2016.03.18 . - ISSN 0017-2278
Аннотация: Slow-rate development of mineral resources in Siberia is connected with remoteness of mineral fields and deficiency in hard-surface roads. The approval of the government transport system program in Siberia requires boosting road metal production and quarrying expansion. Mined-out voids of depleted quarries disturb lands and remain bare for a long time. The situation in the Krasnoyarsk Territory is of particular concern. It is urgently required to find planting methods for mined-out ballast quarries. The obstacle is the traditional geometry of mined-out open pits, with steep walls and vast bottom flooded with atmospheric precipitations. Ecological monitoring of mined-out surface mines in the Krasnoyarsk Territory and most effective vegetation of mined-out voids shows that, given the local climate (long cold winter and short hot summer), population of trees is higher on the southern and eastern pit walls, where moisture content is higher and trees are less dehumidified under the sun in simmer; of no less significance is flatness of slopes and weak inclination (3-5°) of roads towards pit walls, as well as presence of fertile soil layer in the walls. On special purpose plots of land 0.2 ha in area, trees have been counted per each element of a quarry, which makes the basis to develop recommendations on environmentally optimal shape of quarries: maximum area of the southern and eastern pitwalls to be slightly sloping (15-24°), minimum technologically reasoned area of bottom is shifted northwestward. The study is in accordance with the Fundamental Research Program of the National Academies of Sciences for 2013-2020 and the research plan of the Nauka Design and Engineering Center, ICT SB RAS for 2013-2017, under the project "Information Support Models and Technologies for Evaluation, Forecasting and Management of Regional Eco-Systems, Territorial Infrastructure and Natural and Industrial Safety".

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Держатели документа:
Institute of Computational Technologies, Siberian Branch, Russian Academy of Sciences, Krasnoyarsk, Russian Federation
Siberian Federal University, Krasnoyarsk, Russian Federation
Nauka Design and Engineering Center, Krasnoyarsk Division

Доп.точки доступа:
Zenkov, I. V.; Baradulin, I. M.

/ L. Fossati [et al.] // Astron. Astrophys. - 2017. - Vol. 598. - Ст. A90, DOI 10.1051/0004-6361/201629716. - Cited References:48. - We acknowledge the Austrian Forschungsforderungsgesellschaft FFG projects "RASEN" P847963 and "TAPAS4CHEOPS" P853993, the Austrian Science Fund (FWF) NFN project S11607-N16, and the FWF project P27256-N27. N.V.E. acknowledges support by the RFBR grant Nos. 15-05- 00879-a and 16-52-14006 ANF_a. We thank the anonymous referee for the comments that led to a considerable improvement of the manuscript. . - ISSN 1432-0746РУБ Astronomy & Astrophysics

Аннотация: Stimulated by the discovery of a number of close-in low-density planets, we generalise the Jeans escape parameter taking hydrodynamic and Roche lobe effects into account. We furthermore define Lambda as the value of the Jeans escape parameter calculated at the observed planetary radius and mass for the planet's equilibrium temperature and considering atomic hydrogen, independently of the atmospheric temperature profile. We consider 5 and 10 M-circle plus planets with an equilibrium temperature of 500 and 1000 K, orbiting early G-, K-, and M-type stars. Assuming a clear atmosphere and by comparing escape rates obtained from the energy-limited formula, which only accounts for the heating induced by the absorption of the high-energy stellar radiation, and from a hydrodynamic atmosphere code, which also accounts for the bolometric heating, we find that planets whose Lambda is smaller than 15-35 lie in the "boil-off" regime, where the escape is driven by the atmospheric thermal energy and low planetary gravity. We find that the atmosphere of hot ( i.e. T-eq >= 1000 K) low-mass (M-pl <= 5 M-circle plus) planets with Lambda < 15-35 shrinks to smaller radii so that their Lambda evolves to values higher than 15-35, hence out of the boil-off regime, in less than approximate to 500 Myr. Because of their small Roche lobe radius, we find the same result also for hot (i.e. T-eq >= 1000 K) higher mass (M-pl <= 10 M-circle plus) planets with Lambda < 15-35, when they orbit M-dwarfs. For old, hydrogen-dominated planets in this range of parameters, Lambda should therefore be >= 15-35, which provides a strong constraint on the planetary minimum mass and maximum radius and can be used to predict the presence of aerosols and/or constrain planetary masses, for example.

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Держатели документа:
Austrian Acad Sci, Space Res Inst, Schmiedlstr 6, A-8042 Graz, Austria.
SB RAS, Krasnoyarsk Sci Ctr, Fed Res Ctr, Inst Computat Modelling, Krasnoyarsk 36, Russia.
Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany.
Karl Franzens Univ Graz, Inst Geophys Astrophys & Meteorol, Univ Pl 5, A-8010 Graz, Austria.

Доп.точки доступа:
Fossati, L.; Erkaev, N.V.; Еркаев, Николай Васильевич; Lammer, H.; Cubillos, P. E.; Odert, P.; Juvan, I.; Kislyakova, K. G.; Lendl, M.; Kubyshkina, D.; Bauer, S. J.; Austrian Forschungsforderungsgesellschaft FFG projects ["RASEN" P847963, "TAPAS4CHEOPS" P853993]; Austrian Science Fund (FWF) NFN project [S11607-N16]; FWF project [P27256-N27]; RFBR grant [15-05- 00879-a, 16-52-14006 ANF_a]