Collaborative Research: Multi-instrument Studies of Auroral Plasma Radiation

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This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Plasma waves and radiation play key roles in space physics, in some cases playing an important role controlling particle transport, loss rates, or energy exchange, and in other cases serving as a key means of directly or remotely sensing space plasma processes, structures, or boundaries. For all these reasons, understanding emission and propagation of plasma waves and radiation is a top priority in space physics. The proposed research will focus on combining data from the South Pole's set of LF/MF/HF radio receivers with other imaging instruments such as the all-sky cameras and the imaging riometer and electromagnetic wave experiments such as the broadband VLF receiver, the ELF receiver, and the ULF search coils. While it is known that auroral radio emissions are associated with auroral substorms, the methods outlined in this proposal will determine which features of the substorm can be remotely sensed by their radio emissions. The proposed methodology will provide key clues to the generation mechanism of auroral MF-burst, a significant radio emission of unknown cause, and determine whether there is a connection between the recently discovered LF auroral hiss discrete features and those known to occur at VLF. A second proposed method is to adapt relevant plasma theory to the data interpretation, with the help of a plasma theorist with specific experience in auroral plasma waves. By employing theoretical methods such as numerical ray-tracing calculations of mode-converted Langmuir waves and numerical calculations of discrete upper hybrid waves in the presence of non-cylindrical density irregularities, data from the three South Pole 0.1-5.0 MHz receivers can be used to effectively test generation mechanisms of the waves and wave structures. The fieldwork and analysis efforts associated with this project are highly suitable for involvement and research training of graduate students.