Imaging of the atmosphere with infrasound

Ground-truth sources in infrasound are rare but very useful for assessing the accuracy of wind and temperature models for propagation and the propagation itself. In this study, seismic and infrasound signals are used from explosions in Finland observed at the seismic array ARCES in Norway between 2001 and 2006. The seismic signals deliver the ground-truth in terms of origin time and location. The variability in the infrasound signals is caused by the atmosphere as the seismic signals are almost similar throughout the years. Conventional modeling only partly explains the observations. A hypothesis is tested that partly reflections due to fine scale structure in the stratosphere cause arrivals on the edge of the shadow zone. Such phases are not covered by the models.