Geomagnetic pulsations

Abstract

Since the first report by Stewart (186]), pulsations of the earth's electromagnetic field (T,-~0.2-600 sec) have been studied by many researchers under the names of geomagnetic oscillations, fluctuations, micropulsations, pulsations, hydromagnetic (HM) emissions, ULF, and so on. In some cases, even the term giant micropulsations was used. In this review paper, the term geomagnetic pulsations or pulsations will be used. Geomagnetic pulsations have been classified by the researchers into various types under a variety of new names, for example, type A, Lpc, Ilpc, spc, SIP, PSC, etc. At the Berkeley Meeting in 1963, the International Association of Geomagnetism and Aeronomy (IAGA) summarized these various terms and recommended the international classification as listed in Table I.