Temporal and Spatial Changes of Joint Influence of Waves and Water Levels in the Eastern Baltic Sea

Männikus, R.; Viigand, K., and Soomere, T., 2024. Temporal and spatial changes of joint influence of waves and water levels in the eastern Baltic Sea. In: Phillips, M.R.; Al-Naemi, S., and Duarte, C.M. (eds.), Coastlines under Global Change: Proceedings from the International Coastal Symposium (ICS) 2024 (Doha, Qatar). Journal of Coastal Research, Special Issue No. 113, pp. 986-990. Charlotte (North Carolina), ISSN 0749-0208. We analyzed temporal and spatial variability of joint influence of water levels and wave heights in terms of wave run-up on the eastern coast of the Baltic Sea. These shores include long straight sections, mixed with pocket beaches and semi-enclosed gulfs exposed to different wind and wave directions. We use modeled wave data with an hourly temporal and a spatial resolution of ∼6 km for the whole Baltic Sea and a locally nested finer models (up to 1700 m) in the Gulf of Riga and Gulf of Finland. The model was forced with ERA5 wind data set for 1991–2022. Simultaneous values of sea levels from models and water levels from local measurement stations provided input for total wave run-up (water level plus run-up height) calculations. The changes of total run-up were assessed for 30 years to get an insight of trends of the wave climate. Correlations between wave heights and wave run-up showed considerable spatio-temporal differences over the study area.