SGER: Advanced Modular Incoherent Scatter Radar (AMISR) Studies at High-Frequency Active Auroral Research Program (HAARP)

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The investigator will conduct geophysical tests of the Advanced Modular Incoherent Scatter Radar (AMISR), which is currently under development for future deployment in Alaska and Canada. An 8-panel radar production prototype was delivered to the High-Frequency (HF) Active Auroral Research Program (HAARP) facility in January 2005. This is a small sub-unit of the actual radar. The HAARP facility will generate a strong geophysical target (the so-called HF enhanced plasma line) that can be used to test radar reception at frequency offsets from the transmission frequency (nominally 446 MHz). There are several fundamental questions related to radio wave modification of the high-latitude ionosphere that may be answered by the AMISR observations. These include: 1) why is airglow preferentially generated by the HF beam when it is directed parallel to geomagnetic field lines? 2) why are there pronounced overshoots in HF-induced airglow emissions at 630.0 nm? 3) can strong turbulence be detected within the HF standing wave pattern during vertical transmissions at HAARP? and 4) do the enhanced electron temperatures generated when the HF beam is directed parallel to the geomagnetic field give rise to stronger enhanced plasma lines because of reductions in ion Landau damping? The former two questions must be answered under new moon conditions in February/March/April, whereas the latter two questions are best answered under summertime conditions. AMISR is a state of- the-art system with wide-ranging capabilities (e.g., rapid beam scanning, remote operation, and a reconfigurable antenna architecture). This test program will introduce several new HF-modification observing techniques to students and postdoctoral fellows and entails instruction and training of personnel in the interaction of a high-power radio wave with the ionospheric plasma. The wave-plasma physics to be studied scales directly into the dimensional regime of laser plasmas. The great advantage of ionospheric modification experiments is the laboratory-without-walls environment of space, which avoids artifacts caused by particle interactions with laboratory chamber walls. Activities of this nature broaden the education of individuals focused on studies of the natural ionosphere and/or upper atmosphere. Moreover, the test experiments will provide cross-disciplinary training for students studying basic plasma physics. The results of this program will be disseminated through publications in professional journals, public presentations, and other non-refereed publications.