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The solar dynamo is a physical process that generates the Sun's magnetic field.It is explained with a variant of the dynamo theory.A naturally occurring electric generator in the Sun's interior produces electric currents and a magnetic field, following the laws of Ampère, Faraday and Ohm, as well as the laws of fluid dynamics, which together form the laws of magnetohydrodynamics.
In physics, the dynamo theory proposes a mechanism by which a celestial body such as Earth or a star generates a magnetic field. The dynamo theory describes the process through which a rotating, convecting, and electrically conducting fluid can maintain a magnetic field over astronomical time scales.
In the height region between about 85 and 200 km altitude on Earth, the ionospheric plasma is electrically conducting. Atmospheric tidal winds due to differential solar heating or due to gravitational lunar forcing move the ionospheric plasma against the geomagnetic field lines thus generating electric fields and currents just like a dynamo coil moving against magnetic field lines.
However, the solar variability is known to be essentially stochastic and unpredictable beyond one solar cycle, which contradicts the idea of the deterministic planetary influence on solar dynamo. [120] Modern dynamo models are able to reproduce the solar cycle without any planetary influence. [23]
A half-dynamo-cycle corresponds to a single sunspot solar cycle. At a solar maximum , the external poloidal dipolar magnetic field is near its dynamo-cycle minimum strength, but an internal toroidal quadrupolar field, generated through differential rotation, [ 4 ] is near its maximum strength.
The Atmospheric dynamo is a pattern of electrical currents that are set up in the Earth's ionosphere by multiple effects, mostly the Sun's solar wind, but also the tides of the Moon and Sun. [1] [2] The currents flow in circuits between the poles and the equator, but they are not well understood.
Solar wind turbulence displays both magnetohydrodynamic (MHD) and kinetic plasma behaviors. It exhibits Kolmogorov-like power spectra at fluid scales, and shows strong Alfvénic correlations between velocity and magnetic field fluctuations, especially in fast solar wind. It evolves with distance from the Sun as the wind expands.
"Dynamo Electric Machine" (end view, partly section, U.S. patent 284,110) A dynamo is an electrical generator that creates direct current using a commutator.Dynamos were the first electrical generators capable of delivering power for industry, and the foundation upon which many other later electric-power conversion devices were based, including the electric motor, the alternating-current ...