However, the mean currents do not go into the open area west of Bornholm but either follow the coast

straight toward the west or go south into Bornholm. An interesting question is whether it is possible to calculate approximations of the measures from the statistics of the currents only without employing the computationally expensive technique of tracer ensemble simulations. This question is outside the scope of the present study. A certain asymmetry is visible in several places, e.g., east of Gotland, where the maximum is closer to Gotland than Latvia, or south of Bornholm, where the maximum is closer to Bornholm than Poland. The asymmetry south of Bornholm can be explained to a large extent by the small size of the island of Bornholm, which occupies a much narrower sector of directions than the Polish coast at the same distance. The same explanation cannot be applied to the asymmetry east of Gotland. For Instance, the isoline between yellow and Idelalisib ic50 green in Fig. 4 is very close to Gotland but far away from the Latvian coast. However, the southerly currents close to Gotland (see Fig. 3) may explain the asymmetry. There are also northerly currents

along the opposite coast, but the bathymetry in the direction of the currents differs. Many of the investigations of the Gulf of Finland suggest asymmetries in the selleck compound corresponding measures and in the locations of maritime routes (Viikmäe et al., 2011, Andrejev et al., 2011, Soomere et

al., 2011a and Soomere et al., 2011c). The Gulf of Finland is rather symmetrical. Hence, the asymmetries are explained by the patterns of the currents rather than by the bathymetry. For the northern Baltic proper, a very strong asymmetry toward the west is found by Viikmäe et al. (2011). This finding is in contrast to our results, which show a slight, if any, asymmetry toward the east. Viikmäe et al. (2011) attributed the strong asymmetry to the dominating west wind. However, as in this website our study, Viikmäe et al. (2011) have not considered the direct impact of wind on an oil spill. In our study, there are no easterly current components (Fig. 3), which could be the result of preferably westerly wind. A more likely explanation of the asymmetry is provided by the southerly current in the western part of the area, as well as the fact that trajectories are not traced outside of the domain studied by Viikmäe et al. (2011). In Fig. 15, some examples of real routes of tankers carrying hazardous cargo are shown. The routes for these ships have been optimized with respect to fuel consumption and travelling time by considering forecasted currents, waves and wind. Environmental factors are considered only by taking into account areas prohibited by national maritime administration agencies. In general, real maritime routes use more direct paths than those calculated in our study, e.g., most routes go north instead of south of Bornholm.