Trends in the Climatology of Winter Wind Wave Heights in a Back-Barrier Bay in Western North Atlantic Ocean

Abstract

Wave climate studies mainly focus on the wave climatology in the open ocean. There is currently a limited understanding of trends and changes in the wave climatology of coastal waters. This study quantifies climate-induced trends in winter wind-generated wave heights in Jamaica Bay, a back-barrier bay in the western North Atlantic Ocean. A high-resolution hydrodynamic-wave model, forced by pressure and wind fields from a local weather station and the ERA5 reanalysis, is utilized to generate a 30-year (1990–2019) hindcast of wave heights. The model accuracy is evaluated using existing wave height measurements, and the bias in model results is calculated and subtracted from the simulated wave heights. The bias-corrected hindcast is then utilized to determine the wave height climatology and the trends in the mean and extreme (95th percentile) significant wave heights. The study shows that the winter mean and extreme wave heights in Jamaica Bay are 0.12 and 0.5 m, respectively. Based on the trends detected using a linear regression method, the mean and extreme wave heights, averaged in the study area, have increased, respectively, up to 1 and 3 mm/year. The rates of increase in extreme wave heights are generally larger than that in the mean wave height. A decadal trend analysis indicates that the rates of change in wave heights vary in different decades, suggesting that the wave climate change in Jamaica Bay is nonstationary. The increasing waves could cause adverse effects on salt marsh ecosystems in Jamaica Bay, which have already experienced marsh losses since the past century.