Polarization of sudden impulses in the geomagnetic field

Abstract

Sudden impulses in the earth's magnetic field were analyzed by the construction of vector diagrams of the total horizontal disturbance vector ΔH from D and H rapid-run magnetograms for observatories all over the world. At high latitudes the si field was found to be elliptically polarized during the first few minutes of the disturbance. From a comparison of the morphologies of ssc's and si's, it was concluded that si's are also caused by fluctuations in the solar wind energy density and that the perturbations are propagated to the earth's surface by hydromagnetic waves.