A program of upper atmosphere dynamics studies is proposed that involves work at the University of Pittsburgh, at the equatorial Airglow Observatory in Arequipoa, Peru, and at the midlatitude Millstone Hill Observatory in Massachusetts. Determinations of Doppler shifts and widths of nightglow emission lines will be made by upgraded Fabry-Perot interferometer (FPI) instruments to yield velocities and temperatures. The FPIs are of both conventional and all-sky designs that make use of CCD detectors to provide greatly improved sensitivity. Accurate determinations of the Doppler shifts will be provided by zero velocity reference sources, either using the PIs newly developed oxygen afterglow reference source (OARS) that emits the forbidden OI 630.0 and 557.7 nm lines or by more portable Secondary Standard sources that will be interferometrically calibrated against the OARS standard. The improved precision will permit accurate determinations of the (small) vertical velocities, supplementing the usual horizontal velocity determinations to provide a 3-dimensional characterization of the thermospheric flow.
For the equatorial measurements in Peru, the new, multi-wavelength capability of the FPI will broaden the ongoing 630 nm studies of upper thermosphere dynamics to include mesopause wind and temperature determinations via OH (731.6 nm) nightglow line studies. The all-sky FPI at Millstone Hill will be used to examine coupling effects between the midlatitude lower and upper thermosphere by sequential determinations of their wind and temperature fields using the 557.7 nm and 630.0 nm airglow emissions. At both latitudes, the neutral dynamics results can be compared to the ionospheric dynamics measurements obtained by either the Jicamarca or the Millstone Hill incoherent scatter radar.
