Sensitivity of Simulated Infrasound Propagation to Lead Times and Averaging Intervals of Input Meteorological Data

Abstract:

Accurate characterization of the environment is essential for robust predictions of infrasound propagation. In particular, recent efforts have incorporated three-dimensional output from numerical weather prediction models into infrasound propagation models to improve the characterization of the atmosphere. However, three-dimensional weather model output is not always available at the exact times needed for comparison to field experiments involving infrasound propagation. Furthermore, for weather model output that is generated at high temporal frequencies, temporal averaging may be required to smooth out the effects of small-scale, random meteorological phenomena such as turbulence. Therefore, to determine the sensitivity of infrasound simulations to temporal variations of the input meteorological data, a simulation was conducted with the Weather Research and Forecasting (WRF) meteorological model to produce output at a range of lead times (1 minute to 24 hours) preceding an infrasound-producing small explosion from a previous field experiment. The output was also averaged over various temporal intervals (30 minutes to 24 hours). The meteorological output was then incorporated into a wide-angle parabolic equation method (PE) model to predict local infrasound propagation between 1 and 20 Hz, and the sensitivity of infrasound propagation to lead times and averaging intervals of the input meteorological data was calculated. The results of these sensitivity analyses will be discussed.

(This work was funded by the Assistant Secretary of the Army for Acquisition, Logistics, and Technology [ASA{ALT}] under 0602784/T40/24 and 0602146/AR9/01.)

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