Advanced Ground-Based Observations of LF/MF/HF Radio Noise from Auroral Latitudes

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9316126 LaBelle Research funded by NSF during the past year has proven that using inexpensive ground-based instrumentation, it is possible to detect at least two types of radio phenomena at LF/MF/HF frquencoes (0.05- 5.0 MHz) in the auroral zone. These include narrowband emissions near twice and three times the ionospheric electron gyrofrequency and broadband noise enhancements with nulls in the spectrum near harmonies of the gyrofrequency. Although models have been proposed for both these phenomena, their cause is undetermined, as are the range and time variation of their occurrence. We propose to make more advanced measurements of these wave phenomena, including measurements from a chain of stations, with the following objectives: (1) to determine the latitude and time dependence of the waves; (2) to test several specific models for their generation, using wave data and complementary ionosonde, magnetometer, riometer, and all-sky camera data; and (3) to explore the use of these wave observations in combination with CANOPUS/ISTO instrumentation as a ground-based diagnostic of the auroral ionosphere. Although radio emissions comprise a small fraction of the total energy of the Aurora, they may provide important clues to the more energetic processes, in analogy to the way in which solar radio emissions have been used to infer the processes taking place in the solar corona. ***