Gravity Wave Characterization Over Alaska Associated with Geomagnetic Activity

Gravity Waves (GW) are important drivers of the energy and momentum budget in our atmosphere, especially in the ionosphere-thermosphere region, and are commonly associated with Traveling Ionospheric Disturbances (TIDs) in the ionosphere. In the upper atmosphere, interactions between the charged ionosphere and neutral thermosphere are vital to understanding the dynamics of this critical region, but coincident measurements of the neutral and charged regions to observe waves are limited. In this work we present a case study over Poker Flat, Alaska comparing overlapping TID measurements in the ionosphere using incoherent scatter radar electron densities, and GW observations in the thermosphere using scanning doppler imager wind measurements. We focus on short time periods before and after a geomagnetic storm, during which there was no direct auroral activity over Poker Flat, thus TIDs can be associated with sources other than direct ionosphere enhancement from particle precipitation. This case study allows for the study of GW generation arising from a disturbed atmosphere after a strong geomagnetic event, and GW generation in association with geomagnetic activity at other geographic locations not overlapping Poker Flat (e.g. cross-polar propagation of GWs or GW generation at higher latitudes). These results are then compared to model results from the Global Ionosphere-Thermosphere Model.