Lagrangian Modeling of the Marine Surface Pollution Transport in the Southeastern Baltic Sea Using the INMOM Model

Abstract A detailed analysis of passive pollutant dispersion in the water of the southeastern Baltic Sea is carried out using Lagrangian methods. Primary attention is given to modeling the trajectories of passive markers based on surface current fields computed by the INMOM hydrodynamic model for the meteorological conditions of 2014. The numerical experiments have revealed that the pollutant distribution is determined by the combination of alongshore transport, offshore dispersion, and local eddy structures, as well as by seasonal wind dynamics. In spring, there is a shift of polluting particles towards the central part of the sea area, while in summer and autumn, there is an intensification of coastal transport and the formation of extensive alongshore plumes. The study has demonstrated the efficiency of integrating the Lagrangian approach, hydrodynamic modeling, and meteorological data for predicting pollutant dispersion. The obtained results have applied significance for monitoring systems and operational response to oil spills and other types of anthropogenic pollution, as well as for assessing ecological risks and planning measures to protection the Baltic Sea’s coastal ecosystems.