Print Email Facebook Twitter Anomalous infrasound propagation in a hot stratosphere and the existence of extremely small shadow zones Title Anomalous infrasound propagation in a hot stratosphere and the existence of extremely small shadow zones Author Evers, L.G. Van Geyt, A.R.J. Smets, P. Fricke, J.T. Faculty Aerospace Engineering Department Control & Operations Date 2012-03-31 Abstract Long-range infrasound propagation strongly depends on the state of the stratosphere. Infrasound can be efficiently ducted between the Earth's surface and the stratopause under a favorable wind and temperature structure between 40 and 50 km altitude. Understanding infrasound propagation under variable stratospheric conditions is of importance for a successful verification of the Comprehensive Nuclear-Test Ban Treaty, in which infrasound is used as a verification technique. Inversely, infrasound observations can be used in acoustic remote sensing of the upper atmosphere. In previous studies, attention has been paid to the strength and direction of the circumpolar vortex wind. In this study, an analysis is made of the temperature effect in the stratosphere on infrasound propagation. A case study is presented from an explosion during a sudden stratospheric warming. During such conditions, the size of the classical stratospheric shadow zone (?200 km) appeared to be reduced by a factor of 2. The occurrence of such conditions is quantified by evaluating 10 years of atmospheric specifications. It unexpectedly appeared that the size of the shadow zone can become smaller than 100 km, which is confirmed by evaluating infrasound detections from mining blasts in southwestern Siberia, Russia. These results are valid over a latitudinal range of 20°N to 60°N, which is determined by the stratospheric surf zone. Subject infrasoundminingpropagationsudden stratospheric warming To reference this document use: http://resolver.tudelft.nl/uuid:e54b91ae-f6be-4202-bc45-4851a70f5ab7 DOI https://doi.org/10.1029/2011JD017014 Publisher American Geophysical Union ISSN 0148-0227 Source Journal of Geophyscial Research, 117 (D6), 2012 Part of collection Institutional Repository Document type journal article Rights (c) 2012 American Geophysical Union Files PDF Fricke_2012.pdf 1.84 MB Close viewer /islandora/object/uuid:e54b91ae-f6be-4202-bc45-4851a70f5ab7/datastream/OBJ/view