No abstract

The evolution of a beach nourishment project constructed in Long Branch, NJ was investigated using the method of empirical orthogonal functions (EOF). Most applications of EOFs on beach fill projects have focused on traditional linear fills on relatively long, straight, uninterrupted coastlines. The Long Branch project was somewhat unique in that it was designed as a feeder beach and was constructed within a groin field. EOFs were used to analyze shoreline positions and nearshore beach slopes at the site. The first three modes, determined from the shoreline position data set, explain more than ninety percent of the variation from the mean. Mode 1 and Mode 3 illustrate variations of the fill's spreading as material moved in the direction of the net littoral drift, where several shore-perpendicular structures intercepted it. One of these structures was a large outfall pipe, which was shown to have a dominant influence over the shoreline evolution. The second mode was related to seasonal or storm impacts. The EOF analysis of the beach slope data also identified modes related to the spreading of the fill (Mode 2) and seasonal impacts (Mode 1). Overall, the eigenfunctions determined from both data sets reflect the morphological changes which were observed during the field surveys.

Abstract. Two buoys equipped with Doppler lidars owned by the U.S. Department of Energy (DOE) were deployed off the coast ofCalifornia in fall of 2020 by Pacific Northwest National Laboratory. The buoys collected data for an entire annual cycle at twooffshore locations proposed for offshore wind development by the Bureau of Ocean Energy Management. One of the buoys was deployed approximately 50 km off the coast near Morro Bay in central California in 1100 m of water. The second buoywas deployed approximately 40 km off Humboldt County in northern California in 625 m of water. The buoys provided thefirst-ever continuous measurements of the air–sea transition zone off the coast of California. The atmospheric andoceanographic characteristics of the area and estimates of annual energy production at both the Morro Bay and HumboldtWind Energy Areas show that both locations have a high wind energy yield and are prime locations for future floating offshore wind turbines. This article provides a description and comprehensive analysis of the data collected by the buoys is conducted and a final post-processed dataset is uploaded to a data archive maintained by DOE. Additional analysis was conducted to show the value of the data collected by the DOE buoys. All post-processed data from this study are currently available on the Wind Data Hub website, https://a2e.energy.gov/data#. Near-surface, wave, current, and cloud datasets for Humboldt andMorro Bay are provided at 10.21947/1783807 and 10.21947/1959715, respectively. Lidar datasets for Humboldt and Morro Bay are provided at 10.21947/1783809 and 10.21947/1959721, respectively.

The beach fill was constructed using an innovative feeder beach design, rather than a standard linear fill template. The feeder beach design was adopted to address the concerns of local surfing groups by initially burying fewer structures, and by potentially creating additional surfing opportunities through enhanced bar formation during the equilibration process. Nine months of monitoring results show that roughly 84% of the placed material can be accounted for within the project area and on the downdrift beaches. The immediate impact of the fill on the local surfing conditions was negative within the project area as steep slopes, violent plunging breakers, and narrow surfzones limited the use of the feeder beach area; however traditional surf spots to the north and south were unaffected by the nourishment due to the concentrated nature of its placement. More recently, as the post-nourishment slopes have begun to equilibrate, surfing conditions have improved markedly within the project area, while the up drift and down drift beaches remain relatively unaffected.

Abstract. The California Pacific coast is characterized by considerable wind resource and areas of dense population, propelling interest in offshore wind energy as the United States moves toward a sustainable and decarbonized energy future. Reanalysis models continue to serve the wind energy community in a multitude of ways, and the need for validation in locations where observations have been historically limited, such as offshore environments, is strong. The U.S. Department of Energy (DOE) owns two lidar buoys that collect wind speed observations across the wind turbine rotor layer along with meteorological and oceanographic data near the surface to characterize the wind resource. Lidar buoy data collected from recent deployments off the northern California coast near Humboldt County and the central California coast near Morro Bay allow for validation of commonly used reanalysis products. In this article, wind speeds from the Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA-2), the Climate Forecast System version 2 (CFSv2), the North American Regional Reanalysis (NARR), the European Centre for Medium-Range Weather Forecasts Reanalysis version 5 (ERA5), and the analysis system of the Rapid Refresh (RAP) are validated at heights within the wind turbine rotor layer ranging from 50 to 100 m. The validation results offer guidance on the performance and uncertainty associated with utilizing reanalyses for offshore wind resource characterization, providing the offshore wind energy community with information on the conditions that lead to reanalysis error. At both California coast locations, the reanalyses tend to underestimate the observed rotor-level wind resource. Occasions of large reanalysis error occur in conjunction with stable atmospheric conditions, wind speeds associated with peak turbine power production (> 10 m s−1), and mischaracterization of the diurnal wind speed cycle in summer months.