Relevance of wind stress and wave-dependent ocean surface roughness on the generation of winter meteotsunamis in the Northern Gulf of Mexico

Abstract Meteotsunamis associated with passing squall lines are often observed ahead of cold fronts during the winter in the Northern Gulf of Mexico. Winter meteotsunamis occur simultaneously with wind speed variations (~5–20 m/s) and sea-level atmospheric pressure oscillations (~1–6 hPa) with periods between several minutes to 2 h. In order to enhance understanding of meteotsunami generation and propagation, the Coupled-Ocean-Atmosphere-Wave-Sediment Transport (COAWST) modeling system is applied to one of the most intense winter meteotsunamis measured in the Northern Gulf of Mexico during the decade 2009–2018. The model, verified with sea level and atmospheric observations, is able to reproduce the timing and intensity of the wind at 10 m elevation and sea level atmospheric pressure fluctuations. The mean bias between observed and measured wind speeds and atmospheric pressure are 1.73 m/s and 0.63 hPa, respectively. The maximum meteotsunami elevation and its timing are successfully captured with a 7% underestimation of the maximum elevation. The relative effect of atmospheric pressure and wind stress on meteotsunami generation is assessed with different numerical simulations. Results indicate that both wind stress and atmospheric pressure changes contributed to the generation of the meteotsunami. Wind stress was the dominant force in shallow waters (