Wind and wind waves regime climatical changes at the SE Baltic Sea coast

Abstract

Changes of the wind and wave regime at the south eastern coast of the Baltic proper, Lithuanian coast, during last decades can be interpreted, as one of the cause of the changes in the sediment transport at study area. Main changes in the predominant wave direction were noticed in the different years that clarify changes in the annual wave activities. Noticed features estimated from field observations and geomorphic features showed that waves approaching from the south-west direction are the major driver for the coastal processes and cause predominant sediment transport along the Lithuanian coast from the south to north. Wave activity is the major driver of coastal processes along the eastern coast of the Baltic Sea and in many sections of its sub-basins. The Lithuanian sea coast is almost straight and exposed to the wind and wave impact. Changes in the wave regime at the eastern coast of the Baltic proper may cause considerable changes in the coastal processes. Variations in the wind wave dynamics may occur at the main wave parameters, such as wave height and period. Changes in the wave approaching direction also may be significant in the short time period. In this study we analyzed changes of the wave regimes at the south-eastern part of the Baltic proper, Lithuanian coast during last decades. Result show that this research can be interpreted, as one of the cause of the changes in the sediment transport regime at study area. Wave prorogation direction mainly depends on the prevalent wind direction. It should be noted that the intensity of coastal circulation has increased during the research period. Changes in the wind direction induce more repetitive west wave direction. The most frequent wave approach direction was indicated as south-west. The second most frequent direction of wind directions and wave approach directions is either from west. These directions also correspond with the typical direction of strongest winds and have one of the longest fetches in the South-eastern Baltic at the Lithuanian coast. This analysis partly explains changes in the abrasion processes at the Lithuanian coast of the Baltic proper. That allows us to continue further studies of changes in wave's regime in the study area, because of the important practical and economical consequences.