Investigating Tsunami-Ionospheric Coupling Efficiency

Abstract

Coupling has been shown to exist between tsunamis and the upper atmosphere, making their detection in the total electron content (TEC) and the airglow layer possible. However, a quantitative relationship between the strength of the ionospheric signature and the sea level variation remains elusive. Here, we show the ionospheric detection of the 28 October 2012 Haida Gwaii tsunami in both the TEC and the airglow layer. Previously reported ionospheric signatures from the 11 March 2011 Tohoku tsunami are re-explored in comparison to the newer Haida Gwaii detections. Both events provide excellent test cases in the study of tsunami ionospheric coupling efficiency which is most notably affected by the observation geometry and the tsunami propagation direction. A simple a priori model based on the problem geometry is developed that predicts the relative coupling effi ciency while also incorporating the observability of the gravity wave. Predictions are compared to observations and the limitations of the model are discussed in an effort to motivate future studies.