scholarly journals Projected changes in significant wave height toward the end of the 21st century: Northeast Atlantic

2017 ◽  
Vol 122 (4) ◽  
pp. 3394-3403 ◽  
Author(s):  
Ole Johan Aarnes ◽  
Magnar Reistad ◽  
Øyvind Breivik ◽  
Elzbieta Bitner-Gregersen ◽  
Lars Ingolf Eide ◽  
...  
Keyword(s):  
Wave Height ◽  
21St Century ◽  
Significant Wave Height ◽  
Northeast Atlantic ◽  
Significant Wave ◽  
Projected Changes

scholarly journals Projected 21st century changes in extreme wind-wave events

2020 ◽  
Vol 6 (24) ◽  
pp. eaaz7295 ◽  
Author(s):  
Alberto Meucci ◽  
Ian R. Young ◽  
Mark Hemer ◽  
Ebru Kirezci ◽  
Roshanka Ranasinghe
Keyword(s):  
Wave Height ◽  
21St Century ◽  
Significant Wave Height ◽  
High Latitudes ◽  
Extreme Wave ◽  
Significant Wave ◽  
Statistical Confidence ◽  
The North ◽  
Wave Conditions ◽  
Projected Changes

We describe an innovative approach to estimate global changes in extreme wave conditions by 2100, as a result of projected climate change. We generate a synthetic dataset from an ensemble of wave models forced by independent climate simulation winds, enhancing statistical confidence associated with projected changes in extreme wave conditions. Under two IPCC representative greenhouse gas emission scenarios (RCP4.5 and RCP8.5), we find that the magnitude of a 1 in 100-year significant wave height (Hs) event increases by 5 to 15% over the Southern Ocean by the end of the 21st century, compared to the 1979–2005 period. The North Atlantic shows a decrease at low to mid latitudes (≈5 to 15%) and an increase at high latitudes (≈10%). The extreme significant wave height in the North Pacific increases at high latitudes by 5 to 10%. The ensemble approach used here allows statistical confidence in projected changes of extremes.

scholarly journals Projected sea level rise and changes in extreme storm surge and wave events during the 21st century in the region of Singapore

2015 ◽  
Vol 12 (6) ◽  
pp. 2955-3001
Author(s):  
H. Cannaby ◽  
M. D. Palmer ◽  
T. Howard ◽  
L. Bricheno ◽  
D. Calvert ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Wave Height ◽  
21St Century ◽  
Significant Wave Height ◽  
Quantitative Assessment ◽  
Climate Model ◽  
Mean Sea Level ◽  
Significant Wave

Abstract. Singapore is an island state with considerable population, industries, commerce and transport located in coastal areas at elevations less than 2 m making it vulnerable to sea-level rise. Mitigation against future inundation events requires a quantitative assessment of risk. To address this need, regional projections of changes in (i) long-term mean sea level and (ii) the frequency of extreme storm surge and wave events have been combined to explore potential changes to coastal flood risk over the 21st century. Local changes in time mean sea level were evaluated using the process-based climate model data and methods presented in the IPCC AR5. Regional surge and wave solutions extending from 1980 to 2100 were generated using ~ 12 km resolution surge (Nucleus for European Modelling of the Ocean – NEMO) and wave (WaveWatchIII) models. Ocean simulations were forced by output from a selection of four downscaled (~ 12 km resolution) atmospheric models, forced at the lateral boundaries by global climate model simulations generated for the IPCC AR5. Long-term trends in skew surge and significant wave height were then assessed using a generalised extreme value model, fit to the largest modelled events each year. An additional atmospheric solution downscaled from the ERA-Interim global reanalysis was used to force historical ocean model simulations extending from 1980–2010, enabling a quantitative assessment of model skill. Simulated historical sea surface height and significant wave height time series were compared to tide gauge data and satellite altimetry data respectively. Central estimates of the long-term mean sea level rise at Singapore by 2100 were projected to be 0.52 m (0.74 m) under the RCP 4.5 (8.5) scenarios respectively. Trends in surge and significant wave height 2 year return levels were found to be statistically insignificant and/or physically very small under the more severe RCP8.5 scenario. We conclude that changes to long-term mean sea level constitute the dominant signal of change to the projected inundation risk for Singapore during the 21st century. We note that the largest recorded surge residual in the Singapore Strait of ~ 84 cm lies between the central and upper estimates of sea level rise by 2100, highlighting the vulnerability of the region.

scholarly journals Projected sea level rise and changes in extreme storm surge and wave events during the 21st century in the region of Singapore

Ocean Science ◽  
2016 ◽  
Vol 12 (3) ◽  
pp. 613-632 ◽  
Author(s):  
Heather Cannaby ◽  
Matthew D. Palmer ◽  
Tom Howard ◽  
Lucy Bricheno ◽  
Daley Calvert ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Wave Height ◽  
21St Century ◽  
Significant Wave Height ◽  
Quantitative Assessment ◽  
Climate Model ◽  
Mean Sea Level ◽  
Significant Wave

Abstract. Singapore is an island state with considerable population, industries, commerce and transport located in coastal areas at elevations less than 2 m making it vulnerable to sea level rise. Mitigation against future inundation events requires a quantitative assessment of risk. To address this need, regional projections of changes in (i) long-term mean sea level and (ii) the frequency of extreme storm surge and wave events have been combined to explore potential changes to coastal flood risk over the 21st century. Local changes in time-mean sea level were evaluated using the process-based climate model data and methods presented in the United Nations Intergovernmental Panel on Climate Change Fifth Assessment Report (IPCC AR5). Regional surge and wave solutions extending from 1980 to 2100 were generated using  ∼  12 km resolution surge (Nucleus for European Modelling of the Ocean – NEMO) and wave (WaveWatchIII) models. Ocean simulations were forced by output from a selection of four downscaled ( ∼  12 km resolution) atmospheric models, forced at the lateral boundaries by global climate model simulations generated for the IPCC AR5. Long-term trends in skew surge and significant wave height were then assessed using a generalised extreme value model, fit to the largest modelled events each year. An additional atmospheric solution downscaled from the ERA-Interim global reanalysis was used to force historical ocean model simulations extending from 1980 to 2010, enabling a quantitative assessment of model skill. Simulated historical sea-surface height and significant wave height time series were compared to tide gauge data and satellite altimetry data, respectively. Central estimates of the long-term mean sea level rise at Singapore by 2100 were projected to be 0.52 m (0.74 m) under the Representative Concentration Pathway (RCP)4.5 (8.5) scenarios. Trends in surge and significant wave height 2-year return levels were found to be statistically insignificant and/or physically very small under the more severe RCP8.5 scenario. We conclude that changes to long-term mean sea level constitute the dominant signal of change to the projected inundation risk for Singapore during the 21st century. We note that the largest recorded surge residual in the Singapore Strait of  ∼  84 cm lies between the central and upper estimates of sea level rise by 2100, highlighting the vulnerability of the region.

Potential Changes in the Joint Probabilistic Description of the North Atlantic Wave Climate

2018 ◽  
Author(s):  
Elzbieta M. Bitner-Gregersen ◽  
Odin Gramstad
Keyword(s):  
Wave Height ◽  
21St Century ◽  
North Atlantic ◽  
Significant Wave Height ◽  
Wave Climate ◽  
Wave Period ◽  
Simultaneous Occurrence ◽  
Significant Wave ◽  
The Past ◽  
Wave Characteristics

Climate changes include natural climate variability and anthropogenic climate change. The latter is leading to global warming and causes changes in metocean conditions. For most marine structures waves represent the dominant environmental load. Therefore, projections of changes of wave characteristics in the 21st century are crucial with respect to design and marine operations. The study investigates potential changes in simultaneous occurrence of significant wave height and spectral wave period in twelve North Atlantic locations by comparing the past and future wave climate. Two IPCC emission scenarios, with radiative forcing of 4.5 and 8.5 W/m2 by the end of the 21st century, have been selected to project future wave conditions. The third generation (3G) wave model WAM with a resolution of 50 km is used to simulate waves. The model has been forced with winds obtained from six CMIP5 climate models for the historical period 1971–2000 and the future period 2071–2100 for the two emissions scenarios. Wave climate projections obtained from one climate model and one ensemble member are presented herein to indicate potential changes in extreme wave characteristics derived from the long-term joint probabilistic model of significant wave height and spectral wave period. Deviations between the past and future wave climate are shown, given attention to the shape of the joint distribution and wave steepness. Uncertainties associated with the presented results are discussed.

On the Sensitivity of Passive Multistatic Radar Amplitude and Doppler Measurements to Significant Wave Height

2021 ◽  
pp. 1-5
Author(s):  
Jeffrey D. Ouellette ◽  
William T. Bounds ◽  
David J. Dowgiallo ◽  
Jakov V. Toporkov ◽  
Paul A. Hwang
Keyword(s):  
Wave Height ◽  
Significant Wave Height ◽  
Significant Wave ◽  
Multistatic Radar

scholarly journals Estimation of Significant Wave Heights from ASCAT Scatterometer Data via Deep Learning Network

2021 ◽  
Vol 13 (2) ◽  
pp. 195
Author(s):  
He Wang ◽  
Jingsong Yang ◽  
Jianhua Zhu ◽  
Lin Ren ◽  
Yahao Liu ◽  
...  
Keyword(s):  
Deep Learning ◽  
Wave Height ◽  
Significant Wave Height ◽  
Incidence Angle ◽  
Ocean Waves ◽  
Global Scale ◽  
Learning Technology ◽  
Sea State ◽  
Significant Wave ◽  
Wave Heights

Sea state estimation from wide-swath and frequent-revisit scatterometers, which are providing ocean winds in the routine, is an attractive challenge. In this study, state-of-the-art deep learning technology is successfully adopted to develop an algorithm for deriving significant wave height from Advanced Scatterometer (ASCAT) aboard MetOp-A. By collocating three years (2016–2018) of ASCAT measurements and WaveWatch III sea state hindcasts at a global scale, huge amount data points (>8 million) were employed to train the multi-hidden-layer deep learning model, which has been established to map the inputs of thirteen sea state related ASCAT observables into the wave heights. The ASCAT significant wave height estimates were validated against hindcast dataset independent on training, showing good consistency in terms of root mean square error of 0.5 m under moderate sea condition (1.0–5.0 m). Additionally, reasonable agreement is also found between ASCAT derived wave heights and buoy observations from National Data Buoy Center for the proposed algorithm. Results are further discussed with respect to sea state maturity, radar incidence angle along with the limitations of the model. Our work demonstrates the capability of scatterometers for monitoring sea state, thus would advance the use of scatterometers, which were originally designed for winds, in studies of ocean waves.

scholarly journals Physical Modelling of the Effect on the Wave Field of the WaveCat Wave Energy Converter

2021 ◽  
Vol 9 (3) ◽  
pp. 309
Author(s):  
James Allen ◽  
Gregorio Iglesias ◽  
Deborah Greaves ◽  
Jon Miles
Keyword(s):  
Wave Height ◽  
Wave Energy ◽  
Significant Wave Height ◽  
Wedge Angle ◽  
Wave Energy Converter ◽  
Wave Period ◽  
Surface Elevation ◽  
Energy Converter ◽  
Significant Wave ◽  
Model Scale

The WaveCat is a moored Wave Energy Converter design which uses wave overtopping discharge into a variable v-shaped hull, to generate electricity through low head turbines. Physical model tests of WaveCat WEC were carried out to determine the device reflection, transmission, absorption and capture coefficients based on selected wave conditions. The model scale was 1:30, with hulls of 3 m in length, 0.4 m in height and a freeboard of 0.2 m. Wave gauges monitored the surface elevation at discrete points around the experimental area, and level sensors and flowmeters recorded the amount of water captured and released by the model. Random waves of significant wave height between 0.03 m and 0.12 m and peak wave periods of 0.91 s to 2.37 s at model scale were tested. The wedge angle of the device was set to 60°. A reflection analysis was carried out using a revised three probe method and spectral analysis of the surface elevation to determine the incident, reflected and transmitted energy. The results show that the reflection coefficient is highest (0.79) at low significant wave height and low peak wave period, the transmission coefficient is highest (0.98) at low significant wave height and high peak wave period, and absorption coefficient is highest (0.78) when significant wave height is high and peak wave period is low. The model also shows the highest Capture Width Ratio (0.015) at wavelengths on the order of model length. The results have particular implications for wave energy conversion prediction potential using this design of device.

Sign in / Sign up

Export Citation Format

Share Document