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Related papers: Geomagnetic spikes on the core-mantle boundary

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In the framework of turbulence dynamo, flow motions amplify a weak seed magnetic field through the stretching of field lines. Although the amplification process has been a topic of active research, less attention has been paid to the length…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Jungyeon Cho , Dongsu Ryu

A primordial cosmological magnetic field induces and supports vorticity or Alfven waves, which in turn generate cosmic microwave background (CMB) anisotropies. A homogeneous primordial magnetic field with fixed direction induces…

Astrophysics · Physics 2008-11-26 Gang Chen , Pia Mukherjee , Tina Kahniashvili , Bharat Ratra , Yun Wang

The 3D thermal convection in the Boussinesq approximation with heating from below and dynamo in the cube are considered. We study dependence of the convection intensity and magnetic field generation on the latitude in $\beta$-plane…

Fluid Dynamics · Physics 2018-03-06 M. Yu. Reshetnyak

We investigate hydromagnetic turbulence of primordial magnetic fields using magnetohydrodynamics (MHD) in an expanding universe. We present the basic, covariant MHD equations, find solutions for MHD waves in the early universe, and…

Astrophysics · Physics 2014-10-13 Axel Brandenburg , Kari Enqvist , Poul Olesen

We identify all fast-mode forward shocks, whose sheath regions resulted in a moderate (56 cases) or intense (38 cases) geomagnetic storm during 18.5 years from January 1997 to June 2015. We study their main properties, interplanetary causes…

Space Physics · Physics 2016-11-01 N. Lugaz , C. J. Farrugia , R. M. Winslow , N. Al-Haddad , E. K. J. Kilpua , P. Riley

At very high energies the Earth magnetic field, although in many other connections conside red rather weak, acts as a strong field on photons and leptons. This paper discusses the i ntimate connection between this effect and the…

Astrophysics · Physics 2009-11-07 U. I. Uggerhøj

After describing all the contradictions associated with the current Plate Tectonics theory, this paper proposes a model where a single cause can explain all geophysical and geological phenomena. The source of the Earth's activity lies in…

Geophysics · Physics 2016-08-16 André Rousseau

We extend some previous attempts to explain the origin and evolution of primordial magnetic fields during inflation induced from a 5D vacuum. We show that the usual quantum fluctuations of a generalized 5D electromagnetic field cannot…

General Relativity and Quantum Cosmology · Physics 2015-06-05 Federico Agustín Membiela , Mauricio Bellini

Time dependent magnetic fields can be sourced by spinning neutron stars, orbiting binaries and merging neutron stars. We consider electromagnetic radiation from axion condensates in the background of an alternating magnetic field. We find…

High Energy Physics - Phenomenology · Physics 2022-06-15 Srimoyee Sen , Lars Sivertsen

A very strong period of 3592+-57 yrs in 10Be deposition rates from Vostok ice core raw data was detected and verified against concentration raw data at Taylor Dome and Vostok. Data show Hallstadzeit Solar cycle at 2296+-57 yrs, and indicate…

Geophysics · Physics 2009-12-16 M. Omerbashich

Recent analyses of the cosmic microwave background (CMB) maps from the WMAP satellite have uncovered evidence for a hemispherical power anomaly, i.e. a dipole modulation of the CMB power spectrum at large angular scales with an amplitude of…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-28 Christopher M. Hirata

We measure the cosmic microwave background (CMB) power spectrum on angular scales l~30-200 (1-6 degrees) from the QMASK map, which combines the data from the QMAP and Saskatoon experiments. Since the accuracy of recent measurements leftward…

Astrophysics · Physics 2009-10-07 Yongzhong Xu , Max Tegmark , Angelica de Oliveira-Costa

We propose that strong magnetic fields should be generated at shock waves associated with formation of galaxies or clusters of galaxies by the Weibel instability, an instability in collisionless plasmas. The strength of the magnetic fields…

Astrophysics · Physics 2009-11-13 Yutaka Fujita , Tsunehiko N. Kato

Magnetic fields are everywhere in nature and they play an important role in every astronomical environment which involves the formation of plasma and currents. It is natural therefore to suppose that magnetic fields could be present in the…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-22 Dai G. Yamazaki , Kiyotomo Ichiki , Toshitaka Kajino , Grant J. Mathew

It is argued that large scale cosmic magnetic field could be generated in the primeval plasma slightly before hydrogen recombination. Non-zero vorticity, necessary for that, might be created by the photon diffusion in the second order in…

Astrophysics · Physics 2016-08-30 Z. Berezhiani , A. D. Dolgov

On the base of the solar magnetic field measurements obtained in Stanford in 1976--2003 the properties of the cyclic evolution of the large-scale magnetic field are investigated. Some regularities are found in longitudinal and latitudinal…

Astrophysics · Physics 2007-05-23 R. N. Ikhsanov , V. G. Ivanov

The CMB temperature power spectrum offers ambiguous evidence for the existence of horizon-scale power in the primordial power spectrum due to uncertainties in spatial curvature and the physics of cosmic acceleration as well as the observed…

Cosmology and Nongalactic Astrophysics · Physics 2009-07-30 Michael J. Mortonson , Wayne Hu

The Earth's magnetic field can be decomposed into spherical harmonics, and the exact coefficients of the decomposition can be determined through a few measurements of its value at different locations. Using measurements from a magnetometer…

Geophysics · Physics 2025-08-20 Nuno Barros e Sá , Lourenço Faria , Bernardo Alves , Miguel Cymbron

We study the impact of the extra density fluctuations induced by primordial magnetic fields on the reionization history in the redshift range: $6 < z < 10$. We perform a comprehensive MCMC physical analysis allowing the variation of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Kanhaiya L. Pandey , T. Roy Choudhury , Shiv K. Sethi , Andrea Ferrara

We study the evolution of galactic magnetic fields using 3D smoothed particle magnetohydrodynamics (SPMHD) simulations of galaxies with an imposed spiral potential. We consider the appearance of reversals of the field, and amplification of…

Astrophysics of Galaxies · Physics 2016-09-07 C. L. Dobbs , D. J. Price , A. R. Pettitt , M. R. Bate , T. Tricco