Steenbeck, Krause, and Radler were the first to describe how, in this theory, a pseudoscalar quantity dominates the expression for a time-varying field; this instability-causing phenomenon in this theory is called the alpha effect.
Steenbeck, Krause, and Radler were the first to describe how, in this theory, a pseudoscalar quantity dominates the expression for a time-varying field; this instability-causing phenomenon in this theory is called the alpha effect. The fundamental equation of this theory equates the time-derivative of the a field to the curl of the cross product of the velocity with the field, plus the Laplacian of the field times the magnetic diffusivity. If the field derived from this theory is to be steady, it cannot be generated by axisymmetric motion as a consequence of Cowling's theorem. The alpha effect in this theory is complementary to the phenomenon of differential rotation, resulting in the transformation of the poloidal field into a toroidal field and back. In this theory, a field is generated via induction by a moving fluid, and the motion of the conducting fluid across the field generates the current that maintains it. For 10 points, identify this theory which explains how molten fluid in planetary cores generates a planetary magnetic field.
Steenbeck, Krause, and Radler were the first to describe how, in this theory, a pseudoscalar quantity dominates the expression for a time-varying field; this instability-causing phenomenon in this theory is called the alpha effect.
dynamo theory [or geodynamo or solar dynamo; prompt on magnetohydrodynamics] 