Comprehensive Plasma Line Studies at Arecibo Observatory

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This project concerns thermosphere-ionosphere-magnetosphere coupling mechanisms as observed through variations in the ionospheric electron density at the F2 peak. Two established, but seldom utilized, Incoherent Scatter Radar (ISR) electron plasma line techniques that offer high precision information on the ionospheric F-region will be employed at the Arecibo ISR. The plasma line measurements to be conducted will provide very precise foF2 data (measurements of foF2 at kHz accuracy, corresponding to density changes of the order of 100/cm3, and at time scales near one second) as well as electron drift velocity data, which when combined with interleaved standard ISR measurements that yield electron temperature and ion drift data can produce a precise measurement of the vertical current. The techniques will be used together with the dual beam capability of the Arecibo ISR which is a significant advancement compared to earlier experiments utilizing these techniques. The experimental approach has been validated in a pilot-study. Results from the pilot-study reconfirm the presence of broad-band as well as discrete fluctuations and divulge new spatial and temporal features of these. As part of this project, two additional experiments will be conducted at Arecibo to collect a comprehensive data set of the fluctuations. Comparison with other data at Arecibo, including magnetometer measurements, as well as modeling of the ionospheric response to fluctuations and sources of vertical currents will be included in the data analysis. The overarching goal of the research is the identification of the source of the fluctuations. Specific candidates include local ionosphere-thermosphere disturbances, acoustic waves and magnetic field oscillations.Students will participate in the research project through summer internships at Center for Remote Sensing, which will provide unique opportunities for students to get hands-on training and experience with the Arecibo radar and measurement techniques.