An official website of the United States government
This paper evaluates the contribution of waves to the total predicted storm surges in a Hurricane Irma hindcast, using ADCIRC+SWAN and ADCIRC models. The contribution of waves is quantified by subtracting the water levels hindcasted by ADCIRC from those hindcasted by ADCIRC+SWAN, using OWI meteorological forcing in both models. Databases of water level time series, wave characteristic time series, and high-water marks are used to validate the model performance. Based on the application of our methodology to the coastline around Florida, a peninsula with unique geomorphic characteristics, we find that wave runup has the largest contribution to the total water levels on the south and northeast coasts. Waves increase the surge on the south and northeast coasts, due to large fetch and wave runups. On the west coast, the wave effect is not significant, due to limited fetch. However, significant wave heights become greater as the waves propagate into the deep inner gulf. The continental shelf on Florida’s west coast plays a critical role in decreasing the significant wave height and sheltering the coastal areas from large wave effects. Both models underpredict the high-water marks, but ADCIRC+SWAN reduces the underprediction and improves the parity with the observed data, although the scatter is slightly higher than that of ADCIRC.
more »
« less
Arctic Alaska Coastal Hazards Dataset (1979 - 2024)
### Access All files can be accessed and downloaded from the directory via: [http://arcticdata.io/data/10.18739/A2MW28G9D](http://arcticdata.io/data/10.18739/A2MW28G9D). ### Overview Storm surge extremes are intensifying across Arctic coastlines, yet limited observational records hamper detailed spatial and temporal characterization of these events. To address that, this data is a 45-year hydrodynamic hindcast of storm-driven water levels across Northern and Western Alaska. We utilize ADCIRC+SWAN to simulate interactions between the ocean, land, sea ice, and atmosphere, focusing on the period from 1979 to 2024 for Western to Northern Alaska coasts. Data from the European Centre for Medium-Range Weather Forecasts Re-Analysis (ERA5), including sea ice concentration and atmospheric forcing were utilized to support these simulations, which investigate annual conditions in the Alaskan Arctic. The Processed_DATA dataset contains extracted parameters for communities located in western to northern Alaska. For other areas in the state not included here, please refer to the Raw_DATA file. ### Goal The goal of this study's data is to attribute long-term changes in Arctic storm surge extremes to evolving physical drivers—primarily the transition from sea-ice-dominated to wind-driven surge regimes. Furthermore, to fill in the gap in observed water levels and wave conditions throughout Alaska. ### Methods This study’s hindcast model framework is to evaluate the storm driven water levels from 1979 to 2024. The framework integrates a coupled hydrodynamic–wave model driven by time-varying boundary inputs representing atmospheric, oceanic, tidal, and sea ice conditions. We used the coupled Advanced CIRCulation and Simulating WAves Nearshore model (ADCIRC+SWAN) to simulate water levels and wave conditions.
more »
« less
- Award ID(s):
- 1927785
- PAR ID:
- 10639413
- Publisher / Repository:
- NSF Arctic Data Center
- Date Published:
- Subject(s) / Keyword(s):
- Hydrodynamics Waves ADCIRC-SWAN Alaska water levels sea ice Arctic
- Format(s):
- Medium: X Other: text/xml
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Dynamically-coupled SWAN and ADCIRC models have been applied to enhance the predictions of extreme waves and storm surges induced by hurricanes and sea level rise (SLR) in the Gulf of Mexico. The model performance was evaluated using Hurricane Michael, a Category-5 hurricane, as a case study. Modeled wave heights were compared to the observations. Results indicate that the dynamically-coupled SWAN-ADCIRC models substantially enhance the modeling accuracy. By comparing to the maximum observed 2.69 m of wave height near the hurricane landing site, the error is 0.04 m by the SWAN-ADCIRC models in comparison to the 0.39 m by the SWAN stand-alone simulation. Effects of sea level rise on hurricane wave heights were investigated under four SLR scenarios of 0.2m, 0.5m, 1m, and 1.5m. Results indicate that, as sea level rises, wave heights increase non-linearly in shallow waters near the hurricane landing site. At the wave observation station near the hurricane landing site, the ratio of the wave-height change to SLR increases to 117% and the ratio of the combined wave-surge change to SLR increases to 265%. Analysis indicates that this is due to the substantial percentage changes in water depth occurring in shallow water compared to deep water caused by SLR.more » « less
-
Diminishing sea ice is impacting the wave field across the Arctic region. Recent observation and model-based studies highlight the spatiotemporal influence of sea ice on offshore wave climatologies, but effects within the nearshore region are still poorly described. This study characterizes the wave climate in the central Beaufort Sea coast from 1979 to 2019 by utilizing a wave hindcast model that uses ERA5 winds, waves, and ice concentrations as input. The spectral wave model SWAN is calibrated and validated based on more than 10,000 in situ measurements collected over a 13-year time period across the region, with friction variations and empirical coefficients for newly implemented empirical ice formulations for the open water season. Model results and trends are analyzed over the 41-year time period using the non-parametric Mann-Kendall test, including an estimate of Sen’s slope. The model results show that the reduction of sea ice concentration correlates strongly with increases in average and extreme wave conditions. In particular, the open water season extended by ~96 days over the 41-year time period (~2.4 days/yr), resulting in a five-fold increase of the yearly cumulative wave power. Moreover, the open water season extends later into the year, resulting in relatively open-water conditions during fall storms with high wind speeds. The later freeze-up results in an increase of the annual offshore median wave heights of 1% per year and an increase in the average number of rough wave days (defined as days when maximum wave heights exceed 2.5 m) from 1.5 in 1979 to 13.1 days in 2019. Trends in the nearshore areas deviate from the patterns offshore. Model results indicate a non-breaking depth induced saturation limit for high wave heights in the shallow areas of Foggy Island Bay. Similar patterns are found for yearly cumulative wave power.more » « less
-
Hurricane storm surges are influenced by wind intensity, forward speed, width and slope of the ocean bottom, central pressure, angle of approach, shape of coastal lines, local features, and storm size. A numerical experiment is conducted using the Advanced Circulation + Simulation and Simulating Waves Nearshore (ADCIRC + SWAN) coupled model for understanding the effects of wind intensity, forward speed, and wave on the storm surges caused by Hurricane Harvey. The ADCIRC + SWAN is used to simulate hurricane storm surges and waves. The wind fields of Hurricane Harvey were reconstructed from observed data, aided by a variety of methodologies and analyses conducted by Ocean Weather Inc (OWI) after the event. These reconstructed wind fields were used as the meteorological forcing in the base case in ADCIRC+SWAN to investigate the storm surges caused by the hurricane. Hurricane Harvey was the second most costly hurricane in the United States, causing severe urban flooding by dropping more than 60 inches of rainfall in Texas. The hurricane made three landfalls, with its first landfall as a Category 4 based on the Saffir–Simpson Hurricane Wind Scale (SSHWS), with wind intensities of 212.98 km/h (59 m/s). The storm surges caused by Hurricane Harvey were unique due to the slow speed, crooked tracks, triple landfalls in the USA, and excessive rain. The model’s storm surge and wave results were compared against observed data. High water marks at 21 locations and time series at 12 National Oceanic and Atmospheric Administration (NOAA) gauges were compared with the generated results. Several cases were investigated by increasing or decreasing the wind intensity or hurricane forward speed by 25% of the OWI wind and pressure data. The effects of the wave were analyzed by comparing the results obtained from ADCIRC + SWAN (with waves) and ADCIRC (without waves) models. The study found that the changes in wind intensity had the most significant effect on storm surges, followed by wave and forward speed changes. This study signifies the importance of considering these factors to enhance accuracy in predicting storm surges.more » « less
-
### Overview This dataset contains simulated significant wave height data generated from the WaveWatch III model run from 2020 up to 2070. It was produced to predict future environmental hazards threatening maritime navigation within the Arctic. Four unique simulations were produced using different Coupled Model Intercomparison Project Phase 6 (CMIP6) climate models' wind and sea ice projections along the shared socioeconomic pathways 5-8.5 (SSP5-8.5) future emissions scenario. The climate models used include: CNRM-CM6-1-HR, EC-Earth3, MPI-ESM1-2-HR, and MRI-ESM2-0. For each climate model, data is organized into yearly files written to NetCDF format. The data is contained on a spatially-varying unstructured triangular mesh which spans from 50° North (N) to 89.9°N and 180° West (W) to 180° East (E). The 'hs' variable presents the significant wave height (highest one thirds of wave heights) to occur for each node during the simulation in 6 hour intervals. ### Access Data files can be accessed via: [https://arcticdata.io/data/10.18739/A2ST7DZ74/](https://arcticdata.io/data/10.18739/A2ST7DZ74/)more » « less
