High Frequency Radar Studies of the Very High Latitude Ionosphere

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The ionosphere at high latitudes is disturbed by a variety of energy inputs from the magnetosphere, including particle precipitation, electric fields, and the flow of electrical currents, all ultimately originating with the interaction of the solar wind and the outer boundary of the magnetosphere. Ionospheric density irregularities and drifts are present over a wide range of scale sizes and velocities. The deployment of modern radar systems, with sophisticated computer diagnostics and data compression capabilities, allows these irregularities and drifts to be measured as part of a thorough study of the high latitude ionosphere, and provides information for the solution of practical problems associated with radio communication at high latitudes. This award is for continued support of the Johns Hopkins University radar at Goose Bay, Labrador, in conjunction with satellite measurements, other ground based instruments in the area, and a similar radar in Antarctica. The Antarctic radar is at Halley Bay, the magnetic conjugate point, i.e., the place where the magnetic field lines that thread the Goose Bay ionosphere, and extend out many earth radii into the magnetosphere, return to the southern hemisphere ionosphere. The currents, electric fields, and particles from the magnetosphere tend to extend along field lines and be the same at conjugate points, but the differences give important information on the coupling between the magnetosphere and the ionosphere.