Probing Space Weather Events with the Cornell University Portable Radar Imager (CUPRI)

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This project will undertake an upgrade to and continued science investigations with the VHF Cornell University Portable Radar Imager (CUPRI) which will be relocated to Cornell University in Ithaca, NY from Puerto Rico. The primary science focus is high latitude E region plasma instabilities which will be studied through observations of the radar echoes observed by CUPRI. The origin of the echoes remains a subject of debate; until recently, the irregularities were believed to be created during intense energetic particle precipitation. However, two new mechanisms have been proposed. The first involves the generation of instabilities by the steep plasma density gradients associated with storm-enhanced density (SED) structures. The SED features have been observed from the tropics to well beyond the plasmapause. Given the right electric field conditions, the SEDs may cause the plasma to go unstable, creating the small-scale structures required to enhance radar backscatter. Alternatively, there may be a second mechanism responsible for driving plasma instabilities: a temperature gradient instability that has been observed to produce HF scattering over the SuperDARN radar at Wallops Island. These space weather events can result in degraded communication and navigation systems as the primary instabilities cascade to smaller scale lengths, producing scatter with consequential multi-path interference. In addition to investigating the origin of the perturbed echoes, the project will explore three other science questions: (1) do auroral events created by intense energetic particle precipitation, like those previously observed by CUPRI along the poleward edge of visible auroral arcs, relate to, or are they distinguished from, SED structures? (2) will images obtained by CUPRI be correlated with perturbations in total electron content during significant space weather events? (3) can more be learned about auroral plasma physics from measurements of magnetic aspect angles, as has been observed at Jicamarca Radar Observatory? (4) does the temperature gradient instability that causes some of the HF scattering observed over the SuperDARN radar at Wallops Island play a role in VHF scattering observed from Ithaca? The planned upgrades to the CUPRI system include (1) deploying additional antennae and receivers to enable 3-D imaging of the echoes as well as measurements of the magnetic field aspect angle sensitivity of the echoes; (2) replacing analog receivers with digital receivers for improved quality control of the data from different antennae; (3) networking the data acquisition system to provide wide access, including student access, to real time and processed data products; and (4) creating a large networked database. The broader impacts of the project include the provision of extensive hands-on experience in developing, deploying, operating, and maintaining modern radar equipment to graduate and undergraduate students, as well as opportunities in data acquisition, analysis and interpretation. The host institution has demonstrated a strong commitment to including underrepresented groups in its research activity, particularly women and Hispanics, which is expected to continue under this project.