The investigators will use data from a multi-instrument observational campaign centered on Poker Flat Research Range near Fairbanks, AK to study the phenomenon of sustained upward vertical winds (SUVW) in the thermosphere that are associated with the soft particle precipitation of auroral activity. These winds have speeds in excess of 15 meters per second and appear continuously upward over several hours. They are generally preceded by a period of downward winds with speeds of 20 to 30 m/s. Far from being an intriguing curiosity, vertical winds are important to understanding the complex dynamic behavior of the upper atmosphere. Vertical winds in the thermosphere are responsible for vertical mass transport, disrupting stratification and changing the local composition, which can lead to changes in the overall thermal budget. Understanding the underlying source of these sustained vertical upward winds will enable a prediction of the global distribution of their occurrence and their impact on thermospheric dynamics. The study will take advantage of a critical mass of key instruments in the auroral zone in central Alaska that will produce comprehensive data sets to characterize the auroral input and large scale thermospheric conditions leading to the sustained upward vertical wind events. The primary instruments for observing vertical winds will be a set of three imaging Fabry-Perot interferometers (FPI), located at Poker Flat, Fort Yukon and Eagle, AK and dedicated to high-cadence zenith measurements. The contextual instruments include the Poker Flat Incoherent Scatter Radar (PFISR), a set of four scanning Doppler imagers (SDI) at Poker Flat, Gakona, Toolik Field Station, and Kaktovik, AK, all-sky cameras and meridian spectrographs at Poker Flat and remote observing sites. The broader impacts of this work will be the training and educational opportunities for undergraduates in technical research by participating in the analysis of the data obtained by the zenith FPI instruments.
