[Text] : статья / I.L. Arshukova, N.V. Erkaev, H.K. Biernat // International journal of geomagnetism and aeronomy. - 2002. - Vol. 3, № 1. - p. 27–34
Аннотация: This article deals with the magnetohydrodynamic instability of the high magnetic shear magnetopause, which is considered to be a thin layer with a constant curvature radius and plasma velocity shear. In our model, the magnetic field and plasma density are assumed to be piecewise constant in three regions: in the magnetosphere adjacent to the magnetopause, in the magnetosheath, and inside a thin layer associated with the magnetopause. The plasma parameters and the magnetic field are assumed to obey the ideal incompressible magnetohydrodynamics. A Fourier analysis is used to calculate small perturbations of magnetic field and plasma parameters near the magnetopause in a linear approximation. The instability growth rate is obtained as a function of the angle between the velocity vector and the geomagnetic field direction for different plasma bulk speeds, wave numbers and curvature radii. The resulting instability is a mixture of interchange and Kelvin-Helmholtz instabilities on a surface with a nonzero curvature. The instability growth rate is an increasing function of the tangential velocity component perpendicular to the magnetic field. On the other hand, the growth rate is a decreasing function of the velocity component along the magnetic field.
http://icm.krasn.ru/refextra.php?id=2427,
Полный текст
Держатели документа:
ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44
Доп.точки доступа:
Erkaev, N.V.; Еркаев, Николай Васильевич; Biernat, H.K.; Аршукова И.Л.
Труды сотрудников ИВМ СО РАН
w10=
Найдено документов в текущей БД: 11
В3
A80
A80
Instability of the magnetopause with a finite curvature radius and velocity shear
В3
I70
I70
Investigation of MHD slow shocks propagating along the Io flux tube
[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,
Полный текст
Держатели документа:
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.
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,
Полный текст
Держатели документа:
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.
В3
G65
G65
Recovering data gaps through neural network methods
[Text] : статья / A.N. Gorban, A. Rossiev, N. Makarenko, Y. Kuandykov, V. Dergachev // International Journal of Geomagnetism and Aeronomy. - 2002. - Vol. 3, № 2. - p. 191–197
Аннотация: A new method is presented to recover the lost data in geophysical time series. It is clear that gaps in data are a substantial problem in obtaining correct outcomes about phenomenon in time series processing. Moreover, using the data with irregular coarse steps results in the loss of prime information during analysis. We suggest an approach to solving these problems, that is based on the idea of modeling the data with the help of small-dimension manifolds, and it is implemented with the help of a neural network. We use this approach on real data and show its proper use for analyzing time series of cosmogenic isotopes. In addition, multifractal analysis was applied to the recovered 14C concentration in the Earth's atmosphere.
http://icm.krasn.ru/refextra.php?id=2790,
http://ijga.agu.org/v03/gai01384/gai01384.pdf,
Полный текст
Держатели документа:
ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44
Доп.точки доступа:
Rossiev, A.; Россиев, Алексей Анатольевич; Makarenko, N.; Макаренко Н.; Kuandykov, Y.; Dergachev, V.; Горбань, Александр Николаевич
Аннотация: A new method is presented to recover the lost data in geophysical time series. It is clear that gaps in data are a substantial problem in obtaining correct outcomes about phenomenon in time series processing. Moreover, using the data with irregular coarse steps results in the loss of prime information during analysis. We suggest an approach to solving these problems, that is based on the idea of modeling the data with the help of small-dimension manifolds, and it is implemented with the help of a neural network. We use this approach on real data and show its proper use for analyzing time series of cosmogenic isotopes. In addition, multifractal analysis was applied to the recovered 14C concentration in the Earth's atmosphere.
http://icm.krasn.ru/refextra.php?id=2790,
http://ijga.agu.org/v03/gai01384/gai01384.pdf,
Полный текст
Держатели документа:
ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44
Доп.точки доступа:
Rossiev, A.; Россиев, Алексей Анатольевич; Makarenko, N.; Макаренко Н.; Kuandykov, Y.; Dergachev, V.; Горбань, Александр Николаевич
The effect of the magnetopause thickness on the interchange instability of the magnetospheric boundary
[Text] / I. L. Arshukova, N. V. Erkaev // Geomagn. Aeron. - 2000. - Vol. 40, Is. 6. - P692-698. - Cited References: 8
. - ISSN 0016-7932
РУБ Geochemistry & Geophysics
Аннотация: The interchange instability of the magnetospheric boundary at the subsolar point has been considered in the present paper on the basis of the magnetic gas-dynamic model (MGD approximation). The magnetopause is simulated by a thin layer of constant thickness and finite curvature radius. Two cases of changing magnetic field and plasma density at crossing the magnetopause were examined: (1) plasma parameters and the magnetic field are constant inside the magnetopause and change by a jump at its boundaries, and (2) all parameters continuously vary from their values in the magnetosheath to those in the magnetosphere, In the first case, an analytical solution has been found, and the linearized problem of small disturbances of the magnetospheric boundaries has been numerically solved in the second case. The growth rate of intel change instability has been determined depending on the direction of the interplanetary magnetic field, wavenumber, curvature radius of the magnetospheric boundary, and magnetopause thickness.
Доп.точки доступа:
Arshukova, I.L.; Erkaev, N.V.; Еркаев, Николай Васильевич
Рубрики:
KELVIN-HELMHOLTZ INSTABILITY
KELVIN-HELMHOLTZ INSTABILITY
Аннотация: The interchange instability of the magnetospheric boundary at the subsolar point has been considered in the present paper on the basis of the magnetic gas-dynamic model (MGD approximation). The magnetopause is simulated by a thin layer of constant thickness and finite curvature radius. Two cases of changing magnetic field and plasma density at crossing the magnetopause were examined: (1) plasma parameters and the magnetic field are constant inside the magnetopause and change by a jump at its boundaries, and (2) all parameters continuously vary from their values in the magnetosheath to those in the magnetosphere, In the first case, an analytical solution has been found, and the linearized problem of small disturbances of the magnetospheric boundaries has been numerically solved in the second case. The growth rate of intel change instability has been determined depending on the direction of the interplanetary magnetic field, wavenumber, curvature radius of the magnetospheric boundary, and magnetopause thickness.
Доп.точки доступа:
Arshukova, I.L.; Erkaev, N.V.; Еркаев, Николай Васильевич
Penetration of Electric Field from the Near Ground Atmospheric Layer to the Ionosphere
[Text] / V. V. Denisenko, E. V. Pomozov // Geomagn. Aeron. - 2011. - Vol. 51, Is. 7. - P866-872, DOI 10.1134/S0016793211070048. - Cited References: 13. - The work was supported by the Russian Foundation for Basic Research, project no. 09-06-91000. The authors are grateful to A.A. Namgaladze for a substantive, although not consensus-inducing, discussion of the work, as well as to colleagues from the Institute of Cosmic Research of the Austrian Academy of Sciences, with whom jointly this cycle of studies was carried out.
. - ISSN 0016-7932
РУБ Geochemistry & Geophysics
Аннотация: A mathematical model has been proposed for describing quasi-stationary atmospheric electric fields with approximate, but fairly accurate allowance for ionospheric conductivity. It is shown that some well-known models of electric field penetration from the Earth into the ionosphere have been deemed inadequate, though they work well in the atmosphere below 50 km. In these models, the arbitrarily specified boundary condition in the upper boundary of the atmosphere omits the existing good conductor or adds not existent conductor. The maximum possible field in our model is far less than in models where ionospheric conductivity is not taken into account, but vastly larger than in models based on the approximation with infinite Pedersen conductivity in the upper ionosphere.
Доп.точки доступа:
Pomozov, E.V.; Помозов, Егор Владимирович; Денисенко, Валерий Васильевич
Аннотация: A mathematical model has been proposed for describing quasi-stationary atmospheric electric fields with approximate, but fairly accurate allowance for ionospheric conductivity. It is shown that some well-known models of electric field penetration from the Earth into the ionosphere have been deemed inadequate, though they work well in the atmosphere below 50 km. In these models, the arbitrarily specified boundary condition in the upper boundary of the atmosphere omits the existing good conductor or adds not existent conductor. The maximum possible field in our model is far less than in models where ionospheric conductivity is not taken into account, but vastly larger than in models based on the approximation with infinite Pedersen conductivity in the upper ionosphere.
Доп.точки доступа:
Pomozov, E.V.; Помозов, Егор Владимирович; Денисенко, Валерий Васильевич
The effect of viscous friction between the solar wind and plasma sheet on electric field generation in the magnetosphere
[Text] / V. V. Denisenko, S. S. Zamai, A. V. Kitaev // Geomagn. Aeron. - 2003. - Vol. 43, Is. 6. - P680-686. - Cited References: 15
. - ISSN 0016-7932
РУБ 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
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
Variation in the effective conductivity due to motion in the ionosphere
[Text] / V. V. Denisenko, S. S. Zamay // Geomagn. Aeron. - 2001. - Vol. 41, Is. 1. - P91-95. - Cited References: 19
. - ISSN 0016-7932
РУБ Geochemistry & Geophysics
Аннотация: A method for estimating the effect of ponderomotive forces on the distribution of large-scale electric fields and currents in the ionosphere has been proposed. A model of the ionosphere as a global conductor is used to re-calculate local values of the conductivity tensor components in such a way that the acceleration of the medium under the action of ponderomotive forces would be taken into account. A multifold decrease in the F-2-layer effective conductivity has been found for processes lasting for several hours. In this case, the contribution of the entire F layer to the integral conductivity is significantly lowered and becomes negligible for the daytime ionosphere. In the nighttime, the F-layer contribution to the integral Pedersen conductivity several times exceeds the E-layer contribution.
Доп.точки доступа:
Zamay, S.S.; Денисенко, Валерий Васильевич
Аннотация: A method for estimating the effect of ponderomotive forces on the distribution of large-scale electric fields and currents in the ionosphere has been proposed. A model of the ionosphere as a global conductor is used to re-calculate local values of the conductivity tensor components in such a way that the acceleration of the medium under the action of ponderomotive forces would be taken into account. A multifold decrease in the F-2-layer effective conductivity has been found for processes lasting for several hours. In this case, the contribution of the entire F layer to the integral conductivity is significantly lowered and becomes negligible for the daytime ionosphere. In the nighttime, the F-layer contribution to the integral Pedersen conductivity several times exceeds the E-layer contribution.
Доп.точки доступа:
Zamay, S.S.; Денисенко, Валерий Васильевич
Calculation of atmospheric electric fields penetrating from the ionosphere
[Text] / V. V. Denisenko, V. V. Bychkov, E. V. Pomozov // Geomagn. Aeron. - 2009. - Vol. 49, Is. 8. - P1275-1277, DOI 10.1134/S0016793209080489. - Cited References: 4. - This work was supported by the Russian Foundation for Basic Research (project no. 07-05-00135) and the Russian Academy of Sciences (program nos. 2.16 and 16.3).
. - ISSN 0016-7932
РУБ Geochemistry & Geophysics
Аннотация: The spatial distributions of electric fields and currents in the Earth's atmosphere are calculated. Electric potential distributions typical of substorms and quiet geomagnetic conditions are specified in the ionosphere. The Earth is treated as a perfect conductor. The atmosphere is considered as a spherical layer with a given height dependence of electrical conductivity. With the chosen conductivity model and an ionospheric potential of 300 kV with respect to the Earth, the electric field near the ground is vertical and reaches 110 Vm(-1). With the 60-kV potential difference in the polar cap of the ionosphere, the electric field disturbances with a vertical component of up to 13 V m(-1) can occur in the atmosphere. These disturbances are maximal near the ground. If the horizontal scales of field nonuniformity are over 100 km, the vertical component of the electric field near the ground can be calculated with the one-dimensional model. The field and current distributions in the upper atmosphere can be obtained only from the three-dimensional model. The numerical method for solving electrical conductivity problems makes it possible to take into account conductivity inhomogeneities and the ground relief.
Доп.точки доступа:
Denisenko, V.V.; Денисенко, Валерий Васильевич; Bychkov, V.V.; Pomozov, E.V.; Помозов, Егор Владимирович; Russian Foundation for Basic Research [07-05-00135]; Russian Academy of Sciences
Аннотация: The spatial distributions of electric fields and currents in the Earth's atmosphere are calculated. Electric potential distributions typical of substorms and quiet geomagnetic conditions are specified in the ionosphere. The Earth is treated as a perfect conductor. The atmosphere is considered as a spherical layer with a given height dependence of electrical conductivity. With the chosen conductivity model and an ionospheric potential of 300 kV with respect to the Earth, the electric field near the ground is vertical and reaches 110 Vm(-1). With the 60-kV potential difference in the polar cap of the ionosphere, the electric field disturbances with a vertical component of up to 13 V m(-1) can occur in the atmosphere. These disturbances are maximal near the ground. If the horizontal scales of field nonuniformity are over 100 km, the vertical component of the electric field near the ground can be calculated with the one-dimensional model. The field and current distributions in the upper atmosphere can be obtained only from the three-dimensional model. The numerical method for solving electrical conductivity problems makes it possible to take into account conductivity inhomogeneities and the ground relief.
Доп.точки доступа:
Denisenko, V.V.; Денисенко, Валерий Васильевич; Bychkov, V.V.; Pomozov, E.V.; Помозов, Егор Владимирович; Russian Foundation for Basic Research [07-05-00135]; Russian Academy of Sciences
Influence of the atmospheric surface layer on the penetration of the electric field from the earth's surface into the ionosphere
[Text] / E. V. Pomozov // Geomagn. Aeron. - 2014. - Vol. 54, Is. 1. - P127-134, DOI 10.1134/S0016793213060121. - Cited References: 26. - This work was supported by the Russian Foundation for Basic Research, projects nos. 07-05-00135 and 12-05-00152.
. - ISSN 0016-7932. - ISSN 1555-645X
РУБ Geochemistry & Geophysics
Аннотация: In the used model, the quasistationary electric field in the atmosphere of the Earth is obtained by solving the conductivity equation. The penetration characteristics of the electric field from the Earth's surface into the ionosphere depend on both atmospheric and ionosphere conductivity. The ionosphere is taken into account by setting a special condition on the upper boundary of the atmosphere. The influence of the atmospheric surface layer with a reduced conductivity on the penetration of the electric field from the surface of the Earth into the ionosphere is analyzed.
WOS
Держатели документа:
Russian Acad Sci, Inst Computat Modeling, Siberian Branch, Krasnoyarsk 660033, Russia
ИВМ СО РАН
Доп.точки доступа:
Pomozov, E.V.; Помозов, Егор Владимирович; Russian Foundation for Basic Research [07-05-00135, 12-05-00152]
Аннотация: In the used model, the quasistationary electric field in the atmosphere of the Earth is obtained by solving the conductivity equation. The penetration characteristics of the electric field from the Earth's surface into the ionosphere depend on both atmospheric and ionosphere conductivity. The ionosphere is taken into account by setting a special condition on the upper boundary of the atmosphere. The influence of the atmospheric surface layer with a reduced conductivity on the penetration of the electric field from the surface of the Earth into the ionosphere is analyzed.
WOS
Держатели документа:
Russian Acad Sci, Inst Computat Modeling, Siberian Branch, Krasnoyarsk 660033, Russia
ИВМ СО РАН
Доп.точки доступа:
Pomozov, E.V.; Помозов, Егор Владимирович; Russian Foundation for Basic Research [07-05-00135, 12-05-00152]
Pressure balance at the magnetotail boundary
/ A. V. Kitaev // Geomagnetism and Aeronomy. - 1998. - Vol. 38, Is. 5. - P672-674
. - ISSN 0016-7932
Аннотация: The applicability of the well-known Newton pressure formula is analyzed in the context of the problem of interaction between the solar wind and the geomagnetic field. It is shown that this formula may lead to a twofold error in the pressure distribution over the magnetopause in comparison to a numerical simulation of the gasdynamic flow. An example is presented for the determination of the magnetotail shape from the ISEE 3 magnetic data both by the Newton formula and by a numerical calculation of the flow. Copyright В© 1999 by MAHK "Hayka/Interperiodica".
Scopus
Держатели документа:
Institute of Computer Simulations, Siberian Division, Russian Academy of Sciences, Akademgorodok, Krasnoyarsk 660036, Russian Federation
ИВМ СО РАН
Доп.точки доступа:
Kitaev, A.V.; Китаев, Анатолий Валерьевич
Аннотация: The applicability of the well-known Newton pressure formula is analyzed in the context of the problem of interaction between the solar wind and the geomagnetic field. It is shown that this formula may lead to a twofold error in the pressure distribution over the magnetopause in comparison to a numerical simulation of the gasdynamic flow. An example is presented for the determination of the magnetotail shape from the ISEE 3 magnetic data both by the Newton formula and by a numerical calculation of the flow. Copyright В© 1999 by MAHK "Hayka/Interperiodica".
Scopus
Держатели документа:
Institute of Computer Simulations, Siberian Division, Russian Academy of Sciences, Akademgorodok, Krasnoyarsk 660036, Russian Federation
ИВМ СО РАН
Доп.точки доступа:
Kitaev, A.V.; Китаев, Анатолий Валерьевич
Mathematical Simulation of the Ionospheric Electric Field as a Part of the Global Electric Circuit
/ V. V. Denisenko, M. J. Rycroft, R. G. Harrison // Surv. Geophys. - 2018, DOI 10.1007/s10712-018-9499-6
. - Article in press. - ISSN 0169-3298
Кл.слова (ненормированные):
Electric field -- Global electric circuit -- Ionosphere -- Mathematical simulation -- Electric fields -- Electric network analysis -- Electric network parameters -- F region -- Geomagnetism -- Ionosphere -- Ionospheric measurement -- Magnetic fields -- Magnetosphere -- Solar energy -- Thunderstorms -- Timing circuits -- Atmospheric conductivity -- Electric field strength -- Global electric circuit -- Internal electric fields -- Ionospheric electric fields -- Magnetospheric currents -- Mathematical simulations -- Two-dimensional approximation -- Electric lines
Аннотация: Electric currents flowing in the global electric circuit are closed by ionospheric currents. A model for the distribution of the ionospheric potential which drives these currents is constructed. Only the internal electric fields and currents generated by thunderstorms are studied, and without any magnetospheric current sources or generators. The atmospheric conductivity profiles with altitude are empirically determined, and the topography of the Earth’s surface is taken into account. A two-dimensional approximation of the ionospheric conductor is based on high conductivities along the geomagnetic field; the Pedersen and Hall conductivity distributions are calculated using empirical models. The values of the potential in the E- and F-layers of the ionosphere are not varied along a magnetic field line in such a model and the electric field strength is only slightly varied because the segments of neighboring magnetic field lines are not strictly parallel. It is shown that the longitudinal and latitudinal components of the ionospheric electric field of the global electric circuit under typical conditions for July, under high solar activity, at the considered point in time, 19:00 UT, do not exceed 9?V/m, and in the sunlit ionosphere they are less than 2?V/m. The calculated maximum potential difference in the E- and F-layers is 42V; the maximum of the potential occurs above African thunderstorms that are near the terminator at that time. A weak local maximum also exists above the thunderstorm area in Central America. The minimum potential occurs near midnight above the Himalayas. The potential has identical values at ionospheric conjugate points. The voltage increases to 55V at 23:00 UT and up to 72V at 06:00 UT, when local midnight comes, respectively, for the African and Central American thunderstorm areas. These voltages are about twice as large at solar minimum. With our more realistic ionospheric model, the electric fields are an order of magnitude smaller than those found in the well-known model of Roble and Hays (J Geophys Res 84(A12):7247–7256, 1979). Our simulations quantitatively support the traditional presentation of the ionosphere as an ideal conductor in models of the global electric circuit, so that our model can be used to investigate UT variations of the global electric circuit. © 2018, The Author(s).
Scopus,
Смотреть статью,
РИНЦ
Держатели документа:
Institute of Computational Modelling, Siberian Branch, Russian Academy of Sciences, Krasnoyarsk, 660036, Russian Federation
Siberian Federal University, Krasnoyarsk, 660041, Russian Federation
CAESAR Consultancy, Cambridge, CB3 9HW, United Kingdom
Centre for Space, Atmospheric and Oceanic Science, Department of Electronic and Electrical Engineering, University of Bath, Bath, BA2 7AY, United Kingdom
Department of Meteorology, University of Reading, Earley Gate, Reading, RG6 6BB, United Kingdom
Department of Electronic and Electrical Engineering, University of Bath, Bath, BA2 7AY, United Kingdom
Доп.точки доступа:
Denisenko, V. V.; Rycroft, M. J.; Harrison, R. G.
Кл.слова (ненормированные):
Electric field -- Global electric circuit -- Ionosphere -- Mathematical simulation -- Electric fields -- Electric network analysis -- Electric network parameters -- F region -- Geomagnetism -- Ionosphere -- Ionospheric measurement -- Magnetic fields -- Magnetosphere -- Solar energy -- Thunderstorms -- Timing circuits -- Atmospheric conductivity -- Electric field strength -- Global electric circuit -- Internal electric fields -- Ionospheric electric fields -- Magnetospheric currents -- Mathematical simulations -- Two-dimensional approximation -- Electric lines
Аннотация: Electric currents flowing in the global electric circuit are closed by ionospheric currents. A model for the distribution of the ionospheric potential which drives these currents is constructed. Only the internal electric fields and currents generated by thunderstorms are studied, and without any magnetospheric current sources or generators. The atmospheric conductivity profiles with altitude are empirically determined, and the topography of the Earth’s surface is taken into account. A two-dimensional approximation of the ionospheric conductor is based on high conductivities along the geomagnetic field; the Pedersen and Hall conductivity distributions are calculated using empirical models. The values of the potential in the E- and F-layers of the ionosphere are not varied along a magnetic field line in such a model and the electric field strength is only slightly varied because the segments of neighboring magnetic field lines are not strictly parallel. It is shown that the longitudinal and latitudinal components of the ionospheric electric field of the global electric circuit under typical conditions for July, under high solar activity, at the considered point in time, 19:00 UT, do not exceed 9?V/m, and in the sunlit ionosphere they are less than 2?V/m. The calculated maximum potential difference in the E- and F-layers is 42V; the maximum of the potential occurs above African thunderstorms that are near the terminator at that time. A weak local maximum also exists above the thunderstorm area in Central America. The minimum potential occurs near midnight above the Himalayas. The potential has identical values at ionospheric conjugate points. The voltage increases to 55V at 23:00 UT and up to 72V at 06:00 UT, when local midnight comes, respectively, for the African and Central American thunderstorm areas. These voltages are about twice as large at solar minimum. With our more realistic ionospheric model, the electric fields are an order of magnitude smaller than those found in the well-known model of Roble and Hays (J Geophys Res 84(A12):7247–7256, 1979). Our simulations quantitatively support the traditional presentation of the ionosphere as an ideal conductor in models of the global electric circuit, so that our model can be used to investigate UT variations of the global electric circuit. © 2018, The Author(s).
Scopus,
Смотреть статью,
РИНЦ
Держатели документа:
Institute of Computational Modelling, Siberian Branch, Russian Academy of Sciences, Krasnoyarsk, 660036, Russian Federation
Siberian Federal University, Krasnoyarsk, 660041, Russian Federation
CAESAR Consultancy, Cambridge, CB3 9HW, United Kingdom
Centre for Space, Atmospheric and Oceanic Science, Department of Electronic and Electrical Engineering, University of Bath, Bath, BA2 7AY, United Kingdom
Department of Meteorology, University of Reading, Earley Gate, Reading, RG6 6BB, United Kingdom
Department of Electronic and Electrical Engineering, University of Bath, Bath, BA2 7AY, United Kingdom
Доп.точки доступа:
Denisenko, V. V.; Rycroft, M. J.; Harrison, R. G.