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We have developed a new approach to modeling the acoustic-gravity wave (AGW) radiation from bolide sources. This first effort involves entry modeling of bolide sources that have available satellite data through procedures developed in ReVelle (Earth Moon Planets 95, 441-476, 2004a; in: A. Milani, G. Valsecchi, D. Vokrouhlicky (eds) NEO Fireball Diversity: Energetics-based Entry Modeling and Analysis Techniques, Near-earth Objects: Our Celestial Neighbors (IAU S236), 2007b). Results from the entry modeling are directly coupled to AGW production through line source blast wave theory for the initial wave amplitude and period at $$x=10$$ (at 10 blast wave radii and perpendicular to the trajectory). The second effort involves the prediction of the formation and or dominance of the propagation of the atmospheric Lamb, edge-wave composite mode in a viscous fluid (Pierce, J. Acoust. Soc. Amer. 35, 1798-1807, 1963) as a function of the source energy, horizontal range and source altitude using the Lamb wave frequency that was deduced directly during the entry modeling and that is used as a surrogate for the source energy. We have also determined that Lamb wave production by bolides at close range decreases dramatically as either the source energy decreases or the source altitude increases. Finally using procedures in Gill (Atmospheric-Ocean Dynamics, 1982) and in Tolstoy (Wave Propagation, 1973), we have analyzed two simple dispersion relationships and have calculated the expected dispersion for the Lamb edge-wave mode and for the excited, propagating internal acoustic waves. Finally, we have used the above formalism to fully evaluate these techniques for four large bolides, namely: the Tunguska bolide of June 30, 1908; the Revelstoke bolide of March 31, 1965; the Crete bolide of June 6, 2002 and the Antarctic bolide of September 3, 2004. Due to page limitations, we will only present results in detail for the Revelstoke bolide. [ABSTRACT FROM AUTHOR]

We have recently digitized and partially reanalyzed the historic bolide infrasonic database. These 10 events were originally detected by the U.S. Air Force Technical Applications Center (AFTAC) from ∼1960 to 1974. In this paper we present the first preliminary reanalysis results for two of the 10 bolide events, namely the Revelstoke bolide of 3/31/1965 as well as the Prince Edward Islands (P.E.I). S. African bolide of 8/03/1963, which were among the largest bolides detected during this time period. These bolides have been investigated initially since they are most likely to have had a significant effect on the computed global influx rate of ReVelle (Global Infrasonic Monitoring of Large Bolides, pp 483-490, 2001) as indicated in Brown et al. (Nature, 420:314-316, 2002). We are in the process of recomputing all relevant infrasonic propagation quantities such as plane wave back azimuth, signal velocities, power spectra, spectrograms, as well as energy estimates using multiple techniques. In a future paper we will present a complete digital reanalysis of the AFTAC bolide infrasonic data and its final resulting global bolide influx implications. [ABSTRACT FROM AUTHOR]

Recent observations using the newly installed Elginfield infrasound array in coordination with the Southern Ontario all-sky meteor camera network and Canadian Meteor Orbit Radar (CMOR) has shown that the number of meteors producing infrasound at the Earth's surface is more frequent than previously thought. These data show the flux of meteoroids capable of producing infrasound at the ground is at least 1/month and is limited to meteors with peak visual brightness above −2. Comparisons to current meteor infrasound theory show excellent agreement with amplitude and period predictions for weakly non-linear shock waves using a realistic vertically inhomogeneous atmosphere. Similar predictions show isothermal assumptions underestimate the amplitude by orders of magnitude. [ABSTRACT FROM AUTHOR]

The acoustic amplitude-yield relationships, including formal errors, for a population of energetic (>0.05 kt) and well-observed bolide events have been investigated. Using various infrasonic signal measurements as a function of range, these data have been calibrated against optical yield estimates from satellite measurements. Correction for the presence of stratospheric winds has also been applied to the observations and is found to be small, suggesting that either scatter is dominated by other variations amongst the fireball population such as differing burst altitudes and greater or lesser amounts of fragmentation or the magnitude of the variability in the stratospheric winds, which can be comparable to or even exceed the strength of the winds themselves. Comparison to similar point source, ground-level nuclear and high explosive airwave data shows that bolide infrasound is consistently lower in amplitude. This downward shift relative to nuclear and HE data is interpreted as due in part to increased weak non-linearity during signal propagation from higher altitudes. This is a likely explanation, since mean estimates of the altitude of maximum energy deposition along the bolide trajectory was found to be between 20 and 30 km altitude for this fireball population. [ABSTRACT FROM AUTHOR]