How do tsunamis affect the atmosphere?

Tsunamis are known for the great destruction they cause on land. Some recent, devastating tsunamis were observed in Japan and Indonesia. Interestingly, scientists have found that, apart from the lithosphere, our atmosphere is also affected by the tsunamis.
Ionosphere, a layer of atmosphere that lies between 50 and 300 miles (80 and 500 km) above the Earth's surface is primarily affected by the tsunamis. The waves generated by the tsunamis cause ripples in the ionosphere and disturb the electron density in that region of the atmosphere. More specifically, the tsunamis cause gravity waves in the atmosphere and these waves match the horizontal speed of the tsunami (as was observed during the 2011 tsunamis in Japan). The earthquake that caused the 2011 Japan tsunamis also created acoustic and Rayleigh waves that reached the ionosphere. 
An interesting effect of the resulting changes in the ionosphere is the anomalies in GPS data, which may allow the scientists to (someday) detect the tsunami.