Meteo-HySEA: A GPU accelerated code for simulating atmospherically-driven tsunamis on real bathymetries. Evaluating the performance of the newly implemented nested grids system.

Atmospherically-driven tsunamis or meteotsunamis are generated by atmospheric disturbances with steep gradients of pressure and/or wind. In recent years, meteotsunamis have received more attention from the tsunami modelling community. Although their destructive potential might be less severe than for earthquake or landslide generated tsunamis, their frequency is much higher. The two main processes driving the most extreme meteotsunami events are the offshore amplification of the ocean long-waves due to Proudman or Greenspan resonances (i.e., when the atmospheric disturbance travels at the same speed than the long-waves) and, nearshore, the amplification factor of the shelfs, bays or inlets (i.e., resonance frequency associated to the nearshore geometry). As meteotsunamis have a high dependence on the nearshore geometric characteristics, they often occur at known hotspot locations such as along the coastlines of Croatia, the Balearic Islands, Sicily, Malta, the Nagasaki Bay or the Baltic Sea. One of the highest meteotsunami waves ever witnessed (with conservative estimate of up to 6 m in height) took place in Vela Luka (Adriatic Sea, Croatia) on the 21^st of June 1978.

Meteo-HySEA is a GPU accelerated code developed by EDANYA group from the University of Málaga which incorporates the atmospheric forcing together with additional terms such as the Coriolis force and the wind drag to simulate meteotsunami events. After successfully benchmarking the code to replicate laboratory experiments on Proudman resonance and a real-world test case in the Gulf of Mexico using actual topobathymetric data and synthetic pressure data, this updated version of the code introduces the capability to use multiple grids with varying resolutions in a single simulation. This enhancement provides more accurate modelling of Greenspan resonance effects and enables the computation of high-resolution meteotsunami inundation.

The Adriatic Sea was selected as an ideal starting point to showcase the reliability of Meteo-HySEA, given its extensive historical record of meteotsunami events and readily available meteotsunami data. Future efforts will focus on comparing the performance of this code with other existing tools designed for meteotsunami simulations.

Acknowledgments: This contribution was supported by the EU project “A Digital Twin for Geophysical Extremes” (DT-GEO) (No: 101058129) and by the Center of Excellence for exascale in Solid Earth (ChEESE-2P) funded by the European High Performance Computing Joint Undertaking (JU) under grant agreement No 101093038.