Magnetospheric cleft



The magnetospheric cleft is an opening between the earth's magnetic field and the interplanetary field associated with the magnetic poles. Charged particles entering the earth's upper atmosphere cause the airglow or aurora which occurs in the polar regions. At this time of year, as the sun approaches winter solstice and is below the horizon in northern Canada, atmospheric conditions can be studied on the ‘sunside’ of the earth as they appear in the dark from the ground. The cleft offers a unique opportunity to study particle acceleration mechanisms in a regime that is less structured in space and time, as opposed to the highly dynamic nightside auroral region, yet is equally interesting and physically rewarding.