Continuation of Radar Studies of the Equatorial Ionosphere

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This project is concerned with the dynamics of the equatorial upper atmosphere and the ionosphere. The 50 km to 1000 km altitude region of the atmosphere will be probed using a very high frequency (VHF) radar at the Jicamarca Radio Observatory near Lima, Peru. This facility, operated by the Geophysical Institute of Peru with support form the National Science Foundation, is the largest atmospheric VHF radar facility in existence, and the only instrument in its class located at equatorial latitudes. Studies will focus on ionospheric plasma instabilities (processes which disturb the equilibrium distribution of the ionized component of the upper atmosphere above roughly 100 km altitude), and on measurements of winds, atmospheric waves and turbulence in the 50 to 100 kilometer region. The shapes of plasma irregularities along and perpendicular to the geomagnetic field direction will be measured using interferometric radar imaging techniques which make use of multiple receiving antennas; such measurements will aid in developing models of plasma instability evolution. Time resolution will be sufficient to measure the drift velocity and temporal evolution of plasma structures in a field of view of approximately 7 degrees (about 12 km horizontal distance at 100 km altitude). Measurements in the 50 to 100 km region will be aimed at the interactions between wind, wave, and turbulence processes, and the altitude distribution of turbulence strength. Various radar techniques suitable for such measurements will also be improved and compared.