Estonian Science Foundation, Grant 7413 “Spatial and temporal variability of the Baltic Sea wave fields in changing climatic conditions” (Läänemere lainetuse tingimuste ajalis-ruumiline muutlikkus muutuvates kliimatingimustes), 2008–2011. Responsible scientist T. Soomere.
Wave conditions in different parts of the Baltic Sea vary considerably owing to its complex geometry and anisotropy of dominating winds. Both instrumental and visual data (Broman et al. 2006, Soomere and Zaitseva 2007) suggest that the long-term variability of wave fields in the Baltic Proper is weakly correlated with the variations of the average wind speed. Consequently, other properties of wind fields (e.g. the duration of storms, spatial patterns of wind direction, the trajectory and speed of translation of the storms), strongly affect wave properties in this area. This implies that (i) the changes in wave conditions may largely differ in different sectors of the downwind (Estonian) coasts, and (ii) estimates the Baltic Sea wave fields with the use of wind data measured at a few points are not reliable.
We aim at establishing the temporal and spatial variability of the wave properties in the northern Baltic Proper based on the long-term wave hindcast with the use of a high-resolution version of the WAM wave model. The realistic wind patterns and the factual ice conditions will be received from the Swedish Meteorological and Hydrological Institute. The results will be compared with historical wave data (partially digitized from the archives of the Estonian Meteorological and Hydrological Institute and its sister organizations).
The results form an atlas of the Baltic Sea wave fields and allow constructing of multivariate distributions of basic properties of waves for different sectors of the sea. They allow identification of typical and extreme wave conditions in different regions of the sea and the coast as well as their trends and substantial changes, and the spatial pattern of the changes. The influence of the changes in ice conditions on the properties of wave fields and on the course of coastal processes will be analysed as well in parallel with studies into statistics of freak shallow-water waves, sneaker waves, and parameters of wave runup
The results of simulations allow constructing of rapid estimates of wave climate, its changes and extreme conditions for selected regions of the sea. Such estimates have direct applications in navigation and planning of fairways, in planning and assessing of environmental impact of offshore constructions (e.g. wind parks), in planning of various coastal engineering activities, and also in verifying warnings of dangerous sea states in operational forecasts based on lower-resolution models.