This project will continue operating the Low-latitude Ionosphere Sensor Network (LISN) and utilize its regional measurements to investigate the day-to-day variability and formation of structures and dynamics in the low-latitude ionosphere. LISN is a distributed observatory composed of GPS receivers, flux gate magnetometers, and Vertical Incidence Pulsed Ionospheric Radar (VIPIR) ionosondes installed principally in the western half of South America. The work carried out under this grant will collect, store, and disseminate real-time ionospheric observables - a nowcast - and to conduct dedicated campaigns and investigations leading toward developing a predictive capability - a forecast - of the electrodynamics and stability of the low- latitude ionosphere over South America.