Here is a fascinating text that integrates topics pertaining to all scales of the MHD-waves, emphasizing the linkages between the ULF-waves below the ionosphere on the ground and magnetospheric MHD-waves. It will be most helpful to graduate and post-graduate students, familiar with advanced calculus, who study the science of MHD-waves in the magnetosphere and ionosphere. The book deals with Ultra-Low-Frequency (ULF)-electromagnetic waves observed on the Earth and in Space.

The verage morphology of magnetic storms with sudden commencement was studied with 346 magn tic storms that occurred in the years 1902 to 1945. Magnetic recor from 26 observatories were used. The 346 storms were classed into three intensity groups of great, moderate and weak storms, and their morphology was investig ted s par t ly S OR VARI TION WAS ANALYZED INTO WO PARTS, Dst and DS. DS was naly ed harmonically, and its changes with storm time were studied in great detail. The author's present views on stor sudden commencements and on the b ormal nature of t e storm variations at the geomagnetic equator are briefly reviewed. (Author).