A Multidecadal Assessment of Mean and Extreme Wave Climate Observed at Buoys off the U.S. East, Gulf, and West Coasts

Abstract

The current understanding of wind-generated wave climate from buoy-based measurements is mainly focused on a limited number of locations and has not been updated to include measurements in the past decade. This study quantifies wave climate variability and change during the historical period of 1980–2020 through a comprehensive analysis of wave height measurements at 43 buoys off the U.S. Pacific, Atlantic, and Gulf of Mexico Coasts. Variabilities and trends in the annual and monthly mean and 95th percentile significant wave heights (SWH) and the number of extreme wave events are quantified for the cold and warm seasons. We calculate the SWH long-term and decadal trends, and temporal variabilities using the ordinary least squares regression and coefficient of variation, respectively. Independent extreme wave events are identified using a method based on the peaks-over-threshold and the autocorrelation function, which accounts for the geographical variation in the timespan between independent extreme events. Results show that the warm season’s interannual variabilities in monthly and annual SWH are smaller in the Pacific while larger in the Atlantic and Gulf, with the largest variabilities observed at buoys in the Gulf and lower latitudes of the Atlantic. Strong significant alternating decadal trends in SWH are found in the Pacific and Atlantic regions. Buoys in the Atlantic and Gulf regions have experienced higher numbers of extreme wave events (anomalies) compared to the Pacific region. In general, the long-term trend in the number of extreme events during the cold season is positive at buoys located at higher latitudes but negative at lower latitudes.

Historical change and variability of spectral wind wave climate in the New York Bight

“…Wave climate analyses are typically performed based on trends and variabilities in integrated bulk wave parameters such as significant wave height, mean wave period and mean wave direction (El Safty & Marsooli, 2022; Marsooli et al, 2021; Menéndez et al, 2008; Young et al, 2012). Some studies aiming to investigate wave climate trends and variability rely solely on reanalysis data (Dodet et al, 2010) or satellite data (Izaguirre et al, 2011; Stopa, 2021), while others combine them with buoy (Jamous & Marsooli, 2023; Kumar et al, 2018; Loureiro & Cooper, 2018) or altimetry data (Hemer et al, 2010) to verify their findings. Previous wave climate studies have also investigated the relationships between the wave climate and climate indices.…”