Long-Term Contribution of Wind-Generated Waves to the Mean and Extreme Sea Level in Coastal Waters of U.S. East and Gulf Coasts

Coastal communities are vulnerable to sea level changes influenced by different contributing processes ranging from the global scale to localized coastal conditions. Among these processes are wind-generated waves, which can affect coastal sea levels through wave setup, i.e., an increase in the water level due to momentum transfer from breaking waves into the water column. The effect of wave setup is generally pronounced during storms and can contribute significantly to the increase of water level at its peak. While the contribution of wave setup to sea levels at a storm time scale is extensively studied, our understanding of wave setup contribution to long-term sea level change and variability is very limited. The goal of this study is to advance the understanding of long-term changes in sea level due to wave setup along the Atlantic coast. To achieve this goal, a high-resolution regional-scale coupled circulation-wave model (ADCIRC+SWAN) is utilized to simulate the water level and waves in the Western North Atlantic Ocean for a historical period. We use atmospheric forcing, water level, and wave spectra data from the ERA5 reanalysis dataset to force the model at its boundaries. The water levels are then simulated in the presence and absence of waves in order to quantify the contribution of wave setup. Model results are statistically analyzed to determine the long-term contribution of waves to both mean and extreme water levels along the U.S. East and Gulf Coasts.