magnetic crochet

plural magnetic crochets

1. natural sciencesA portion of a magnetograph recording showing electric currents in the Earth's ionosphere caused by a solar flare, identified by its characteristic shape, likened to a crochet hook.

   Figure 3 illustrates the short wave fade-out and the magnetic crochet, both of which endure only so long as the burst of x-rays from the flare continues.

   1966, James Robert Place, Magnetic disturbances and the equatorial electrojet, page 7

   2 more examples

   Back then, the hump was called a magnetic crochet because of its hook-like shape on graphs. Crochets appeared in both the declination and horizontal components. But, the synoptic analyses by Cliver and Svalgaard indicated the magnetic crochet in the horizontal component was among the largest ever reported.

   2010, Taylor A. Cisco, Jr, All Shall Hide, page 70

   1969, John Marshall, R. Alan Plumb, J. Van Mieghem (series editor), Atmosphere, Ocean and Climate Dynamics: An Introductory Text, International Geophysics Series, page 191, With regard to the magnetic crochet, we recall that the conductivity per ion pair is so small below 80 km that huge changes of electron concentration would be required to enable sizable electric currents to flow.