Studying infrasound propagation in the middle atmosphere with UA-ICON: parameterisation and characterisation of gravity waves with the Multi-Scale Gravity Wave Model

Infrasound signals are used to monitor various anthropogenic and natural sources. To determine accurate source locations and energy, an accurate model of wind and temperature from the surface up to the lower thermosphere is necessary, hence operational NWP products are of great importance for routine infrasound monitoring activities. However, many of these models focus on tropospheric conditions, and the middle and upper atmosphere, where the relevant infrasound waveguides for long-range propagation are found, is not well represented. UA-ICON is an upper atmosphere version of the ICOsahedral Non-hydrostatic weather and climate model (ICON) that provides modelled atmospheric parameters up to 150 km. From an infrasound perspective, small-scale perturbations - most notably gravity waves - can have a large impact on propagation due to the effects on both the background winds and temperatures, hence on the acoustic waveguides, but also due to the small perturbations they produce, which cause partial reflections of acoustic waves. Therefore, the transient-3D Multi-Scale Gravity Wave Model (MSGWaM) was used within UA-ICON to produce accurate background conditions, and predict the global gravity wave activity. We will present the methodology used to generate the wind and temperature gravity wave perturbation profiles, as well as analysis of infrasound propagation using these gravity wave realisations.