NOAA National Data Buoy Center Research Articles

A significant wave height forecast framework with end-to-end dynamic modeling and lag features length optimization

Ocean wave energy is attracting more and more attention from researchers on observation of its clean and sustainable properties. Significant wave height (SWH) is one of the key wave parameters, making accurately forecasting the SWH important for coastal/ocean engineers. In this paper, we propose a new framework for forecasting the SWH. The data were decomposed and reconstructed, and the lag features length of the input data were adaptively optimized using the Bayesian optimization (BO) algorithm. A new paradigm for end-to-end dynamic modeling (EEDM) forecast is then proposed, where data are modeled and forecasted separately for buoys at various geographical locations, with automated machine learning (AutoML) as the back-end modeling support for the paradigm. It was also trained and tested on nine buoys from NOAA National Data Buoy Center, which are located at sites with different water depths. The results show that the forecast framework has provided reliable forecasts. We also discussed the reasons for the buoy with the worst forecast in terms of model interpretability and data quality. Finally, we compared three deep learning models (simple recurrent network, long short-term memory and gate recurrent unit) and three machine learning models (principal component regression, support vector machine and K-nearest neighbor). The comparisons indicate that the AutoML turns out to be the best.

Performance Evaluation of the Newly Operational NDBC 2.1-m Hull

Abstract The importance of quantifying the accuracy in wave measurements is critical to not only understand the complexities of wind-generated waves, but imperative for the interpretation of implied accuracy of the prediction systems that use these data for verification and validation. As wave measurement systems have unique collection and processing attributes that result in large accuracy ranges, this work quantifies bias that may be introduced into wave models from the newly operational NOAA National Data Buoy Center (NDBC) 2.1-m hull. Data quality consistency between the legacy NDBC 3-m aluminum hulls and the new 2.1-m hull is compared to a relative reference, and provides a standardized methodology and graphical representation template for future intrameasurement evaluations. Statistical analyses and wave spectral comparisons confirm that the wave measurements reported from the NDBC 2.1-m hulls show an increased accuracy from previously collected NDBC 3-m hull wave data for significant wave height and average wave period, while retaining consistent accuracy for directional results, purporting that hull size does not impact NDBC directional data estimates. Spectrally, the NDBC 2.1-m hulls show an improved signal-to-noise ratio, allowing for increase in energy retention in the lower-frequency spectral range, with an improved high-frequency spectral accuracy above 0.25 Hz within the short seas and wind chop wave component regions. These improvements in both NDBC bulk and spectral data accuracy provide confidence for the wave community’s use of NDBC wave data to drive wave model technologies, improvements, and validations.

Utilizing data from the NOAA National Data Buoy Center

Utilizing data from the NOAA National Data Buoy Center

Modeling Subsurface Oil Transport and Concentrations during the Response to the Deepwater Horizon Oil Spill

Abstract Beginning 22 April 2010, crude oil was released from the Deepwater Horizon well for 84 days at about 1600m below the water surface in the northeastern Gulf of Mexico. Sampling was performed throughout the water column in areas near the well and downstream, to document the distribution of the contamination and calibrate/validate modeling of oil fate and exposure for Natural Resource Damage Assessment purposes. Real-time Acoustic Doppler Current Profiler (ADCP) measurements of currents were down-loaded off the NOAA National Data Buoy Center (NDBC) website and interpolated to develop a 3-dimensional and time-varying current file that was used as input to the oil fate model (Spill Impact Model Application Package, SIMAP). Daily model runs indicated oil droplet and dissolved hydrocarbon distributions throughout the water column, as well as where oil should be surfacing and in elevated concentrations in subsurface layers, such that adaptive sampling could be performed by placing stations in appropriate...

Wave spectral energy variability in the northeast Pacific

The dominant characteristics of wave energy variability in the eastern North Pacific are described from NOAA National Data Buoy Center (NDBC) buoy data collected from 1981 to 2003. Ten buoys at distributed locations were selected for comparison based on record duration and data continuity. Long‐period (LP) [T > 12] s, intermediate‐period [6 ≤ T ≤ 12] s, and short‐period [T < 6] s wave spectral energy components are considered separately. Empirical orthogonal function (EOF) analyses of monthly wave energy anomalies reveal that all three wave energy components exhibit similar patterns of spatial variability. The dominant mode represents coherent heightened (or diminished) wave energy along the West Coast from Alaska to southern California, as indicated by composites of the 700 hPa height field. The second EOF mode reveals a distinct El Niño‐Southern Oscillation (ENSO)‐associated spatial distribution of wave energy, which occurs when the North Pacific storm track is extended unusually far south or has receded to the north. Monthly means and principal components (PCs) of wave energy levels indicate that the 1997–1998 El Niño winter had the highest basin‐wide wave energy within this record, substantially higher than the 1982–1983 El Niño. An increasing trend in the dominant PC of LP wave energy suggests that storminess has increased in the northeast Pacific since 1980. This trend is emphasized at central eastern North Pacific locations. Patterns of storminess variability are consistent with increasing activity in the central North Pacific as well as the tendency for more extreme waves in the south during El Niño episodes and in the north during La Niña.

The Keweenaw Current and Ice Rafting: Use of Satellite Imagery to Investigate Copper-rich Particle Dispersal

The immense surface area and large volume of Lake Superior causes thermal characteristics to resemble marine waters, yet the completely bounded shoreline and low flushing rate introduce unique features. Previously, shoreline inputs were considered minor, as annual river discharges account for only 0.36% of the total hydrologic volume of the lake. However, thermal bar formation and wind shear from prevailing westerlies impound warm waters along the southern coastline, creating a coastal exposure corridor with strong counterclockwise circulation known as the Keweenaw Current. Discharges from rivers and industrial sources are confined, then entrained. Here infrared AVHRR (Advanced Very High Resolution Radiometer) satellite imagery was utilized, verified by NDBC (NOAA National Data Buoy Center) buoy surface data, to document thermal features of offshore waters and the coastal zone. Five stamp mills at Freda/Redridge discharged over 45 million metric tons of stamp sands between 1895 and 1922. The coarse fraction forms beach sands that now extend 23 kilometers north from their sources and that blanket shallow-water sandy sediments. The finer fractions disperse much farther than the coarse fractions, moving along the primary track of the Keweenaw Current. SPOT and TM (Thematic Mapper) imagery were used to document how Ontonagon clays and Freda/Redridge stamp sand particles are entrained by the Keweenaw Current. The two particle types have distinctive reflective spectra. An additional transport mechanism, revealed by RADARSAT ScanSAR (Synthetic Aperature Radar) imagery, is ice rafting. Nearshore ice incorporates large amounts of coastal sands and deeper-water sediments. Spring break-up of coastal ice results in large drifting ice packs that are pushed by prevailing westerlies and currents around the tip of the Keweenaw Peninsula into the Caribou Basin.