Development and Application of an Integrated Infrasound Propagation Modeling Tool Kit

Infrasound propagation models and upper-atmospheric characterizations have been integrated into a single software tool kit that allows for user-friendly model execution and data visualization. The tool kit, called InfraMAP, for Infrasonic Modeling of Atmospheric Propagation, can be applied to predict travel times, bearings, and amplitudes from potential event locations worldwide. Temporal and spatial variability of the atmosphere is addressed by allowing range-dependent sound speed and winds to be incorporated with the propagation models. The ability to predict propagation characteristics necessary for localization is therefore enhanced. The integrated software has been used to conduct sensitivity analyses and to model infrasound propagation corresponding to historical events of interest. Results from these analyses and comparisons of predictions with measurements are discussed. InfraMAP integrates three types of research-grade propagation models with two empirically based atmospheric models. The baseline set of acoustic propagation models consists of a three-dimensional ray theory model (HARPA), a WKB version of Pierce’s normal mode model, and a continuous-wave, twodimensional parabolic equation model. The baseline empirical atmospheric models are the Horizontal Wind Model (HWM) and the Extended Mass Spectrometer Incoherent Scatter Radar (MSIS or MSISE) temperature model. Wind, temperature, and densities are modeled from the surface into the thermosphere and include spatial, diurnal, and seasonal effects. The InfraMAP tool kit provides a common user interface that allows researchers to use these models efficiently for investigating issues of interest for CTBT monitoring.