Understanding the physics of ionospheric structures

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A comprehensive study of the ionosphere is central to an understanding of the electrodynamic and thermodynamic processes that link atmospheric winds from below and the solar wind from above to the upper atmosphere, with important implications for our technology through "space weather" impacts. We are coming to the realization that the system is full of large amplitude structures and is highly turbulent. This means that most of the key ionospheric properties and coupling mechanisms with other regions must depend on the presence of structures in time and space. With this in mind, the central focus of this proposal is to study ionospheric structures over a wide range of latitudes and scales from combined theoretical and observational approaches. This includes studying the origin of ionospheric plasma irregularities, of their evolution, and of their impact on the larger system. The research will also scrutinize how plasma irregularities can be used to diagnose the state of the ionosphere and how plasma instabilities affect the coupling of the ionosphere with the thermosphere and the magnetosphere. The studies will focus specifically on (1) the origin and evolution of meter to decameter plasma instabilities in the ionosphere between 100 and 1000 km altitudes; (2) the electrodynamic and thermodynamics taking place in 10 to 100 km auroral structures. This will include a study of the mechanisms responsible for the escape of ions from the ionosphere; (3) the origin and evolution of patches of plasma at high to very high latitudes; and (4) the ionospheric response to sudden temporal changes in the solar wind be it because of strong southward excursions in the solar wind magnetic field or through solar wind shocks hitting the earth. We will also consider the global ramifications of the magnetic storms triggered by the solar wind, through a study of their impact all the way to the equatorial regions.