frozen magnetic field line
xatt-e meydân-e meqnâtisi-ye yax basté, ~ ~ ~ rocidé
Fr.: ligne de champ magnétique gelée
Of or pertaining to → geomagnetism.
žirandegi-ye zamin-meqnâtisi, ~ zamin-meqnâti
Fr.: activité géomagnétique
Fr.: excursion géomagnétique
A geophysical event, distinguished from the → magnetic reversal, in which the Earth's magnetic field departs for a relatively short time from its usual near axial configuration, without establishing a reversed direction. During the excursion the intensity and direction of the Earth's magnetic field undergo drastic changes. Palaeomagnetic measurements have revealed that since the last full reversal the Earth's magnetic field has, for brief intervals, deviated from the behavior expected during "normal" secular variation.
meydân-e zamin-meqnâtisi, ~ zamin-meqnâti
Fr.: champ géomagnétique
The magnetic field that is generated within the Earth and extends out around the Earth. The intensity of the magnetic field at the Earth's surface is about 0.32 → gauss at the equator and 0.62 gauss at the north pole.
tufân-e zamin-meqnâtisi, ~ zamin-meqnâti
Fr.: orage géomagnétique
Same as → magnetohydrodynamics.
interplanetary magnetic field
meydân-e meqnâtisi-ye andarsayyârei
Fr.: champ magnétique interstellaire
The magnetic field that is carried along with the solar wind and fills the solar system space. It is wound into a spiral structure by the rotation of the Sun. At the Earth's distance from the Sun, it has a strength of about 5 x 10-5 gauss.
interstellar magnetic field
meydân-e meqnâtisi-ye andaraxtari
Fr.: champ magnétique interstellaire
A large-scale, weak magnetic field, with an estimated strength of about 1 to 5 microgauss, that pervades the disk of the Milky Way Galaxy and controls the alignment of interstellar dust grains.
longitudinal magnetic field
meydân-e meqnâtisi-ye derežnâyi
Fr.: champ magnétique longitudinal
1) A → magnetic field whose lines of force
(→ line of force)
run parallel to the long axis of the → magnet.
of a component can be accomplished using the longitudinal field set
up by a → coil or
→ solenoid. It can also be accomplished using
permanent magnets or electromagnets.
meqnâtisi (#), meqnâti, âhanrobâyik
Of or pertaining to a magnet or magnetism.
Fr.: advection magnétique
The transport of the magnetic field by a fluid. It is given by the term ∇ x (v x B) in the → induction equation.
Fr.: axe magnétique
botri-ye meqnâtisi (#)
Fr.: bouteille magnétique
Fr.: freinage magnétique
The process whereby a star which loses mass slows down under the action of its → magnetic field. The stellar material follows the → magnetic field lines extending well beyond the stellar surface. The material gain → angular momentum and the underlying object is slowed down. Magnetic braking is an efficient mechanism for removing angular momentum from the the rotating object. See also → disk locking.
Fr.: rayonnement de freinage magnétique
Same as → synchrotron radiation.
Fr.: flottabilité magnétique
The phenomenon whereby the presence of a → magnetic field can make a portion of → compressible fluid less dense than its surroundings, so that it floats upward under the influence of gravity. This magnetic buoyancy is thought, in fact, to be the mechanism by which magnetic flux tubes rise through the Sun's → convection zone and break at the surface in the form of → sunspots. The Sun's rotation would have a major effect on the rate at which these magnetic flux tubes rise. The rotation substantially lengthen the time taken for the flux tubes to reach the surface (D. J. Acheson, 1979, Nature 277, 41).
magnetic cataclysmic binary
dorin-e gatluri-ye meqnâtisi
Fr.: binaire cataclysmique magnétique
A cataclysmic binary in which the white dwarf primary has a strong magnetic field that radically affects the accretion flow in the system. → polar
Fr.: nuage magnétique
A transient ejection in the → solar wind having an enhanced field, a large and smooth change in field direction, and a low → proton temperature compared to the ambient proton temperature (L. F. Burlaga, 1995, Interplanetary Magnetohydrodynamics, Oxford Univ. Press, 89-114).
Fr.: compas magnétique