Numerical modelling of meteotsunami wave induced currents in Marinas using SPH

Meteotsunami waves entering harbour basins can generate rapid and potentially hazardous sea-level oscillations and associated currents, posing a serious threat to navigation, mooring safety, and port infrastructure. Large commercial ports are typically subdivided into multiple interconnected but functionally distinct basins, each serving specific operational purposes. Among these, small recreational marinas – although integral to major port systems – are often particularly vulnerable due to their limited spatial extent, complex geometry, and reduced hydrodynamic damping. The Smiltynė marina within the Port of Klaipėda represents a characteristic example of such a setting. In this study, we aim to numerically reconstruct the meteotsunami-induced water-level variability and the spatial distribution of current velocities observed during documented events in the Port of Klaipėda, with a specific focus on the hydrodynamic response of the Smiltynė marina using a Smoothed Particle Hydrodynamics modelling framework.

Smoothed Particle Hydrodynamics (SPH) is a mesh-free, fully Lagrangian numerical method that has become increasingly important for simulating complex free-surface flows in coastal and harbour environments. In contrast to traditional grid-based models, SPH represents the fluid as a collection of discrete particles that move with the flow, allowing for a natural treatment of large deformations, rapidly evolving water surfaces, and non-linear hydrodynamic processes. These characteristics are particularly relevant for meteotsunami events, which are often associated with short-lived but intense water-level oscillations and strongly transient current patterns in confined basins.

The particle-based formulation of SPH enables accurate representation of complex and irregular harbour geometries, narrow basins, and interactions with coastal structures without the need for dynamic remeshing. This is a key advantage when modelling small marinas, where localized flow acceleration, basin-scale resonance, and wave–structure interactions can play a dominant role in determining hydrodynamic response. Furthermore, SPH is well suited for resolving fluid–structure interactions and extreme flow conditions near quays and mooring facilities, where conventional depth-averaged or grid-based approaches may struggle to capture spatial heterogeneity. Owing to its ability to directly couple long-wave propagation, resonance processes, and current generation within a single modelling framework, SPH provides a robust and flexible tool for investigating meteotsunami-induced water-level variability and current velocities in small harbour environments. These capabilities make SPH particularly valuable for hazard assessment, operational risk evaluation, and infrastructure-oriented analyses in marinas exposed to extreme long-wave forcing. The first modelling results allow the identification of the most hazardous quays for vessel mooring under meteotsunami forcing. These findings are of direct relevance to marina operators, vessel owners, and coastal engineers, providing a scientific basis for risk-aware operational decisions and for the future planning and development of the marina infrastructure. This study was partially funded by the WaveWise project, which received funding from the Research Council of Lithuania (LMTLT) under agreement No. SMIP-24-140.