Performance of operationally calculated hydrodynamic forecasts during storm surges in the Pomeranian Bay and the Szczecin Lagoon

The modified hydrodynamic model of the Baltic Sea, developed at the Institute of Oceanography, University of Gdansk was validated using storm-related sea level fluctuations as well as water temperature and salinity variations in the Pomeranian Bay and the Szczecin Lagoon (southern Baltic). The high resolution (about 300 m) applied to the model for the Szczecin Lagoon area resulted in a much better description of the area's bathymetry, and in an improved fit between the modelled and the observed distributions of the data sets both in the Bay and in the Lagoon. Model quality tests involving 2002―2007 storm surge events showed a better representation of events characterised by rapid water level fluctuations and fast changes of physical water properties. The numerical model's high quality of simulations allows for applying the higher resolution of spatial spacing to the Szczecin Lagoon area also in the operational version of the model.