The goal of this project is to delineate and understand variability in the mesosphere-lower thermosphere due to the interaction of atmospheric tides and planetary waves. The approach is to employ temperature measurements from the TIMED and EOS satellites, data recorded by ground-based wind radars, and an observation-driven, nonlinear mechanistic model. Satellite data will be used to diagnose planetary waves and to recover the spectrum of diurnal tides. Global tidal winds will be computed from the observed temperature tides, and synthesized at longitudes and latitudes of individual radars. A comparative analysis with the radar data will then be used to validate the global tidal winds and to illuminate the extent to which local temporal variations can be attributed to global-scale influences including cross-hemisphere coupling. The underlying mechanisms and origins of tide-planetary wave interaction, including forcing terms, relative importance compared to other tidal sources and the role of atmospheric background conditions will be diagnosed from various model runs.
