This project seeks to improve our understanding of ionospheric irregularities, building on recent work at high southern latitudes that demonstrated a clear connection between the interplanetary magnetic field (IMF) and irregularity production in the auroral E-region. The fundamental issue to be addressed is solar control of irregularity production via indirect IMF effects versus direct effects of solar-induced ionization. This study will focus on evaluating the extent of IMF control of small-scale irregularities and the relationship to other scales. The project will address the question of whether the presence of the polar patches is a necessary condition for irregularity production, and whether solar illumination suppresses or enhances irregularity generation. Inter-hemispheric differences will be investigated to determine the relative importance of solar wind drivers versus solar ionization.
Earlier studies of small-scale plasma irregularities have analyzed local observations using rockets and/or radio techniques. This project will analyze irregularity production in the polar cap in context of its global drivers focusing on observations from the first US Antarctic HF (SuperDARN) radar at McMurdo, Antarctica and complementary instrumentation. The polar cap ionosphere is directly connected to the solar wind; hence, one can expect IMF effects on small-scale irregularity production to be even more pronounced than in the previously studied auroral region. The polar cap also has reasonably uniform solar ionization conditions near solstices and sharp contrasts between seasons, so solar illumination effects can be revealed more clearly. In addition, the polar cap appears to be especially rich in irregularities.
This project will leverage data from the NSF-funded Antarctic facilities, providing essential support for a newly-established faculty researcher in the US, and expand a graduate student training program in the geosciences area in Alaska.
