Numerical study of meteotsunamis driven by atmospheric gravity waves in coastal waters of Buenos Aires Province, Argentina

Abstract

The generation and propagation of meteorological tsunamis (meteotsunamis) were numerically investigated in coastal waters of Buenos Aires Province. This study was carried out using a vertically integrated ocean model driven by a theoretical atmospheric forcing. This forcing simulates a train of nondispersive atmospheric gravity waves (AGW) propagating within a bounded area that moves at the speed of the synoptic systems. Firstly, a study case of simultaneous AGW and meteotsunami activity was simulated to validate the implemented methodology. Subsequently, after several numerical experiments, it was obtained that the amplitude, the dominant period, and the direction of propagation of the AGW train were the parameters that have the largest impact on the simulated meteotsunami amplitude. Maximum meteotsunami wave height (0.85 m) was obtained at Punta Rasa (the northern extreme of the coast of Buenos Aires Province) when the AGW reached this location. Numerical outcomes also showed that the meteotsunamis would propagate like ocean edge waves. In these cases, the continuous transference of energy from the atmosphere to the ocean could be possible (Greenspan resonance). Even though the implemented theoretical forcing is realistic, the numerical experiments revealed that some particular issues should be enhanced to better simulate the genesis and propagation of the meteotsunamis in coastal waters of the Buenos Aires Province. These issues are analyzed and discussed in this paper.