Electromagnetic Waves and their Effects in near-Earth Space

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At the start of the space age, James Van Allen made a startling discovery: the space above our atmosphere is filled with high-energy radiation. That was in 1958, and the discovery soon made him Time Magazine's "Man of the Year". Much has changed since that time, and our society has come to rely on orbiting satellites. Applications such as GPS positioning and satellite weather maps are a part of our daily lives. However, the radiation that Van Allen discovered is a natural phenomenon, and modern satellites often cross through the two doughnut-shaped regions now known as the Van Allen radiation belts. The radiation in these regions comes from electrons and ions which are trapped by the Earth's magnetic field and accelerated to very high energies. These particles pose a serious threat to any satellites passing through them, mostly due to their ability to damage and disrupt on-board electronics. Starting from the mid-1990s, it became increasingly apparent that we have only a limited understanding of how the particles in the radiation belts reach such high energies, or what processes cause them to be occasionally released into our atmosphere or into deep space. Older physical models simply could not explain their dynamic and hard-to-predict nature. There is presently a focussed international effort to remedy this and to fully understand the radiation belts, with a dedicated mission recently launched by NASA and closely related projects from several nations including Canada. This proposal requests funds to examine the role of a class of electromagnetic waves known as "whistler-mode" waves in both accelerating radiation belt particles and releasing them from the belts. It uses a unique combination of Canadian and international resources, both space- and ground-based, in order to maximize the Canadian scientific return from the upcoming intense period of radiation belt investigation.