Results 271 to 280 of about 7,951 (302)

Dynamic geomagnetic field models

Geomagnetism and Aeronomy, 2011
A review of modern dynamic models of the Earth’s magnetosphere (the A2000 paraboloid model and Tsyganenko’s T01 model) is presented. For the magnetic storm of January 9–11, 1997, the results of joint calculations of the magnetospheric magnetic field are presented and contributions of the large-scale magnetospheric currents to the Dst variations are ...
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Poloidal and toroidal fields in geomagnetic field modeling

Reviews of Geophysics, 1986
The theory of surface operators is described and applied to four surface operators on spheres: the dimensionless surface gradient, ▽1=r▽‐r∂r; the dimensionless surface curl, ; the dimensionless surface Laplacian, ▽1²=▽1 · ▽1; and the Funk‐Hecke operators, integral operators with axisymmetric kernels.
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Geomagnetic Core Field Models in the Satellite Era

2010
After a brief review of the theoretical basis and difficulties that modelers are facing, we present three recent models of the geomagnetic field originating in the Earth’s core. All three modeling approaches are using recent observatory and near-Earth orbiting survey satellite data. In each case the specific aims and techniques used by the modelers are
Lesur, V., Olsen, N., Thomson, A.
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Mathematical model of the geomagnetic field for 1965

Journal of Geophysical Research, 1966
A mathematical model of the geomagnetic field for 1965.0 is presented. The field is given by internal and external spherical harmonic coefficients to degree and order 12. This model was derived from approximately 425,000 measurements made since 1900. An important step in the derivation was the analytic smoothing of data, which produced the regularly ...
L. Hurwitz, D. G. Knapp, J. H. Nelson, D. E. Watson   +3 more
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A Phenomenological Model for Reversals of the Geomagnetic Field

1989
We consider a system made by N point interacting dipoles, each of them having a finite lifetime. A renewal process for the dipoles gives the time evolution of the system. When the number N of dipoles is low, and for a wide range of the coupling between the dipoles, we observe sudden transitions or excursions between two polarised states.
Mazaud, A., Laj, C., Bard, E.
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An Overview of Geomagnetic Field Models

1980
Abstract : Over the last decade, the utility of geomagnetic field models or the mathematical representations of the geomagnetic field has expanded considerably, both for civilian and military applications. Such an increase has been accompanied with more interest in models and demands for better accuracies with resultant changes in techniques of model ...
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Mathematical Methods of Geomagnetic Field Modeling

2017
The geomagnetic field, as the Earth’s magnetic field is called, extends from Earth’s interior to outer space. The magnetosphere is the region defined by the areal extent and the shape of the magnetic field of a celestial body, like the planet Earth.
Stavros Kolios, Andrei V. Vorobev, Gulnara R. Vorobeva, Chrysostomos Stylios   +3 more
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Operational modelling of geomagnetic fields and geomagnetically induced currents

2022
Geomagnetically induced currents (GICs) have long been known to affect power systems adversely. Modelling these GICs usually involves consideration of a chain of coupled systems. The scope of the modelling chain spans multiple disciplines, from solar physics through to geophysics and power engineering.
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Models of the geomagnetic field on the territory of the Republic of Macedonia

2008
The aim of this paper is to present various geomagnetic field models of Macedonia based on measurements at repeat stations as well as satellite data covering this region. At first a theoretical basis of the geomagnetic field, spherical cap harmonical model and polynomial model will be given.
Panovska, Sanja, Delipetrov, Todor, Delipetrev, Marjan, Delipetrev, Blagoj   +3 more
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Regional geomagnetic field model for Croatia

2015
Geomagnetic components at Croatian repeat stations and ground survey sites, as well as European observatories and repeat stations, were used to obtain a regional geomagnetic model over Croatia at 2009.5 epoch. Different models were derived, depending on input data, and the modelling techniques were Adjusted Spherical Harmonic Analysis and Spherical ...
Vujić, Eugen, Kovács, Peter, Brkić, Mario, Varga, Matej   +3 more
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