Seasonal Impacts of Atmospheric Tides on High-Latitude Gravity Waves

Atmospheric gravity waves (GWs) are significant drivers of middle-and-upper atmosphere momentum transport. Breaking GWs contribute to drag on background winds, which significantly influences the mean flow and circulation of the mesosphere and lower thermosphere (MLT). Currently, GWs are parameterized in many global circulation models (GCMs), and GWs with horizontal wavelengths <200 km often remain altogether unresolved. Further, measurements of GW-tide coupling remain limited in the polar region due to logistical constraints. As a result, long-term analysis of regular GW observations remains critical for the high-latitude environment. We present a seasonal analysis of concurrent, high-frequency OH-layer images and meteor radar measurements from Poker Flat, Alaska (65°N 147°W), comparing varying tidal amplitudes and phases with GW prominences for winter months. In doing so, we analyze the tidal influence on background winds and effective GW propagation over longer timespans than commonly available, shedding light on GW-tide coupling in the polar region.