Monday, 23 January 2012: 2:15 PM
Highlights From the 2011 CASA Infrasound Field Experiment
Room 340 and 341 (New Orleans Convention Center )
Severe weather such as tornadoes produces infrasound. Tornado generated infrasound can travel long distances allowing it to be detected by remote sensors. Infrasound sites with arrays of sensors can determine the azimuth angle pointing back in the direction of the infrasound source. Triangulation of the azimuths from two or more infrasound sites can geolocate the infrasound source. If the infrasound sites are sufficiently close to the infrasound source, the geolocated detections could aid in tornado detection and warning. Recently, Paroscientific, Inc. made a firmware upgrade to its Model 6000-16B resonant crystal barometric pressure instruments that allow them to detect the entire range of infrasound frequencies (www.paroscientific.com). Using this instrument, the NSF Engineering Research Center for Collaborative Adaptive Sensing of the Atmosphere (CASA) has launched a pilot study to understand the various ways that infrasound might be integrated into the weather prediction, forecasting, warning, and response infrastructure. At the 2011 AMS Conference in Seattle, WA, we described a planned field experiment involving the deployment of two infrasound sites in the heart of “tornado alley” southwest of Norman Oklahoma (Pepyne et al, "An Integrated Radar-Infrasound Network for Meteorological Infrasound Detection and Analysis", 91st Annual Meeting of the AMS, 15th Symposium on IOAS-AOLS, http://ams.confex.com/ams/91Annual/webprogram/Paper185435.html). As promised in that paper, this paper presents the results of that field experiment. After describing the final deployment of the two infrasound sites, the paper describes the infrasound signal processing algorithms used, highlights the results, discusses lessons learned, and outlines planned improvements for a redeployment for the 2012 tornado season. Taking place during a particularly active and deadly tornado season, our results contain a detailed analysis of the detections that occurred as well as the missed detections that we believe should have occurred. This work is supported by the Engineering Research Centers Program of the National Science Foundation (NSF) under NSF Cooperative Agreement EEC-0313747, with additional funding provided by the Jerome M. Paros Fund for Measurement and Environmental Sciences Research, and the NSF Research Experience for Undergraduates (REU) program.