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Related papers: Kinetic Helicity in the Earth's atmosphere

200 papers

We derive horizontal fluid motions on the solar surface over large areas covering the quiet-Sun magnetic network from local correlation tracking of convective granules imaged in continuum intensity and Doppler velocity by the Helioseismic…

Solar and Stellar Astrophysics · Physics 2016-06-29 C. R. Sangeetha , S. P. Rajaguru

We demonstrate that the inclusion of the helicity flux in the magnetic helicity balance in the nonlinear stage of galactic dynamo action results in a radical change in the magnetic field dynamics. The equilibrium value of the large-scale…

Astrophysics · Physics 2007-05-23 N. Kleeorin , D. Moss , I. Rogachevskii , D. Sokoloff

The existence of a second quadratic inviscid invariant, the helicity, in a turbulent flow leads to coexisting cascades of energy and helicity. An equivalent of the four-fifth law for the longitudinal third order structure function, which is…

chao-dyn · Physics 2007-05-23 P. D. Ditlevsen , P. Giuliani

We present a new approach to the definition of optical helicity in a medium. Our approach resolves the problem that duality transformations which simultaneously combine $\mathbf{E}$ with $\mathbf{H}$ and $\mathbf{D}$ with $\mathbf{B}$ are…

The evolution of the magnetic helicity tensor for a nonzero mean magnetic field and for large magnetic Reynolds numbers in an anisotropic turbulence is studied. It is shown that the isotropic and anisotropic parts of the magnetic helicity…

Astrophysics · Physics 2008-11-26 N. Kleeorin , I. Rogachevskii

Mass currents in astrophysics generate gravitomagnetic fields of enormous complexity. Gravitomagnetic helicity, in direct analogy with magnetic helicity, is a measure of entwining of the gravitomagnetic field lines. We discuss…

General Relativity and Quantum Cosmology · Physics 2022-03-23 Donato Bini , Bahram Mashhoon , Yuri N. Obukhov

By defining an appropriate field line helicity, we apply the powerful concept of magnetic helicity to the problem of global magnetic field evolution in the Sun's corona. As an ideal-magnetohydrodynamic invariant, the field line helicity is…

Solar and Stellar Astrophysics · Physics 2017-07-05 A. R. Yeates , G. Hornig

We present new simulations of decaying hydromagnetic turbulence for a relativistic equation of state relevant to the early universe. We compare helical and nonhelical cases either with kinetically or magnetically dominated initial fields.…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-29 Axel Brandenburg , Tina Kahniashvili , Sayan Mandal , Alberto Roper Pol , Alexander G. Tevzadze , Tanmay Vachaspati

Helicity is a quadratic invariant of the Euler equation in three dimensions. As the energy, when present helicity cascades to smaller scales where it dissipates. However, the role played by helicity in the energy cascade is still unclear.…

Fluid Dynamics · Physics 2009-08-13 Paola Rodriguez Imazio , Pablo Daniel Mininni

The effect of kinetic helicity (velocity--vorticity correlation) on turbulent momentum transport is investigated. The turbulent kinetic helicity (pseudoscalar) enters the Reynolds stress (mirrorsymmetric tensor) expression in the form of a…

Fluid Dynamics · Physics 2016-04-06 Nobumitsu Yokoi , Axel Brandenburg

The theory of large scale dynamos is reviewed with particular emphasis on the magnetic helicity constraint in the presence of closed and open boundaries. In the presence of closed or periodic boundaries, helical dynamos respond to the…

Astrophysics · Physics 2009-11-07 A. Brandenburg , W. Dobler , K. Subramanian

Spatial buoyancy-helical distributed chaos (turbulence) in the cumulus, stratiform, stratocumulus, cirrus and cirrus mammatus clouds have been studied using results of direct numerical simulations and measurements in cloudy atmosphere. It…

Atmospheric and Oceanic Physics · Physics 2021-04-14 A. Bershadskii

A likely candidate mechanism to heat the solar corona and solar wind is low-frequency "Alfv\'enic" turbulence sourced by magnetic fluctuations near the solar surface. Depending on its properties, such turbulence can heat different species…

Solar and Stellar Astrophysics · Physics 2024-09-17 Jonathan Squire , Romain Meyrand , Matthew W. Kunz

Both dissipation of helicity and it spectrum we are study on the basis of asymptotic model. Introduction into model dependence of angle between turbulent components vorticity and velocity on the governing parameters leads to the spectra of…

Fluid Dynamics · Physics 2009-11-13 O. G. Chkhetiani , E. Golbraikh

One of the greatest challenges in solar physics is understanding the heating of the Sun's corona. Most theories for coronal heating postulate that free energy in the form of magnetic twist/stress is injected by the photosphere into the…

Solar and Stellar Astrophysics · Physics 2019-09-25 Kalman J. Knizhnik , Spiro K. Antiochos , James A. Klimchuk , C. Richard DeVore

Helicity transfer in a shell model of turbulence is investigated. We show that a Reynolds-independent helicity flux is present in the model when the large scale forcing breaks inversion symmetry. The equivalent in Shell Models of the ``2/15…

chao-dyn · Physics 2009-10-30 L. Biferale , D. Pierotti , F. Toschi

The electromagnetic helicity of the free electromagnetic field and the static magnetic helicity are shown to be two different embodiments of the same physical quantity, the total helicity. The total helicity is the sum of two terms: a term…

Optics · Physics 2021-02-03 Ivan Fernandez-Corbaton

A version of model is proposed, which is aimed for getting parameters of the atmospheric layer and upper water layer with account of the wind-wave state. The dynamics of the atmospheric boundary layer is realized in version of papers [1,…

Atmospheric and Oceanic Physics · Physics 2011-08-12 Vladislav Polnikov , Iliya Kabatchenko

We perform a study on the evolution of helical quantum turbulence at different temperatures by solving numerically the Gross-Pitaevskii and the Stochastic Ginzburg-Landau equations, using up to $4096^3$ grid points with a pseudospectral…

Fluid Dynamics · Physics 2018-09-26 P. Clark di Leoni , P. D. Mininni , M. -E. Brachet

We examine the relationship between magnetic flux generation, taken as an indicator of large-scale dynamo action, and magnetic helicity, computed as an integral over the dynamo volume, in a simple dynamo. We consider dynamo action driven by…

High Energy Astrophysical Phenomena · Physics 2017-07-19 G. Bodo , F. Cattaneo , A. Mignone , P. Rossi