Averkiev A. S.
The results of level rise simulation in the Gulf of Finland during the passage of the extreme and realy observed cyclones over the Baltic Sea are presented. The analytical expression of atmospheric pressure field when passing intense cyclones was developed in the model of the Baltic Sea, which reproduces storm surges. This allows to simulate a wide range of trajectories and parameters of dangerous cyclones and resulting dangerous fluctuations in water level in the Gulf of Finland. Operation of St.-Petersburg Flood Protection Barrier was considered in the numerical experiments. It is shown that local level slope occurs in the Neva Bay under the closed Flood Protection Barrier and this slope can reach dangerous values. The simulation results are confirmed by level observations in the Gulf of Finland and in the Neva Bay during floods 2011 and 2013. These floods in St.-Petersburg were actually prevented. However, a more thorough analysis of the model calculations and the characteristics of specific cyclones will allow to carry out Protection Barrier gates maneuvers with most optimal way in the future.