Atmospheric Specifications for Infrasound Studies: 2. The Added Value of a High‐Top Model, UA‐ICON

Abstract Infrasound monitoring activities that deal with long‐range acoustic propagation, as within the Comprehensive Nuclear‐Test‐Ban Treaty's (CTBT), need accurate and operational modeling of the atmosphere up to the lower thermosphere. Yet, operational meteorological products issued by weather services are topped at around 80 km altitude with a sponge layer starting in the stratosphere. This prevents reliable simulation of atmospheric dynamics where infrasound waveguides form. Hence, investigating higher‐top atmospheric models enabling simulations at typical operational horizontal resolutions ( km) are of high interest to improve the description of the propagation medium, which is needed to localize and characterizes acoustic sources of interest. The extension of the ICOsahedral Nonhydrostatic (ICON) model to the upper‐atmosphere, UA‐ICON with a model top of 150 km, is run at the ICON operational horizontal resolution. Simulations are compared with LiDAR observations at three different sites and with operational analyses. We demonstrate the better performance of the UA‐ICON simulations compared to operational models in the mesosphere, especially for the temperature field while it is less clear for the winds. This is achieved by tuning the nonorographic gravity wave (GW) parameterization coefficient that drives the saturation and breaking of the waves. Additionally, infrasound propagation simulations are performed using UA‐ICON atmospheric specifications. For the two case studies, one at high latitudes and one in tropical regions, we demonstrate the added value of the UA‐ICON with a tuned GW parameterization, while also illustrating how infrasound can contribute to model validation and tuning in the upper‐atmosphere.