Payload 02 Information

Abstract:
The generation and propagation of acoustic waves provide valuable constraints on source processes (e. g. volcanoes, meteorites, and severe storms) as well as atmospheric structure. However, existing acoustic and infrasound arrays, in nearly all cases, lie on the surface of the Earth and thus neglect the three dimensional radiation pattern of acoustic energy. We propose to address this shortcoming with a balloon-mounted acoustic array. The payload will consist of an acoustic array, a high altitude GPS, and an instrument deployment system. The array will include infrasonic microphones with attached data loggers separated by 12 m of wire; this system will be deployed in-flight and will extend below the payload module. This experiment will test the accuracy of existing infrasound propagation models that lack constraints in the atmosphere, search for acoustic waveguides at the tropopause, and potentially detect never-before recorded signals that do not reach the Earth's surface. The atmospheric propagation models will be evaluated by recording mine blasts from southwestern New Mexico. The existence of waveguides will be tested as the balloon transits the tropopause. The long flight time will give ample opportunities for recording novel signals in the mid-stratosphere.