Assessment of Future Wave Climate on basis of Wind-Wave- Correlations and Climate Change Scenarios (original) (raw)
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Projection of Global Wave Climate Change toward the End of the Twenty-First Century
Journal of Climate, 2013
Wind-generated waves at the sea surface are of outstanding importance for both their practical relevance in many aspects, such as coastal erosion, protection, or safety of navigation, and for their scientific relevance in modifying fluxes at the air–sea interface. So far, long-term changes in ocean wave climate have been studied mostly from a regional perspective with global dynamical studies emerging only recently. Here a global wave climate study is presented, in which a global wave model [Wave Ocean Model (WAM)] is driven by atmospheric forcing from a global climate model (ECHAM5) for present-day and potential future climate conditions represented by the Intergovernmental Panel for Climate Change (IPCC) A1B emission scenario. It is found that changes in mean and extreme wave climate toward the end of the twenty-first century are small to moderate, with the largest signals being a poleward shift in the annual mean and extreme significant wave heights in the midlatitudes of both he...
Projection of global wave climate change towards the end of the twenty-first century
J. Climate, 2013
Wind generated waves at the sea surface are of outstanding importance for both their practical relevance in many aspects, such as coastal erosion, protection, or safety of navigation, and for their scientific relevance in modifying fluxes at the air-sea interface. So far long-term changes in ocean wave climate have been studied mostly from a regional perspective with global dynamical studies emerging only recently. Here a global wave climate study is presented, in which a global wave model (WAM) is driven by atmospheric forcing from a global climate model (ECHAM5) for present day and potential future climate conditions represented by the IPCC (Intergovernmental Panel for Climate Change) A1B emission scenario. It is found that changes in mean and extreme wave climate towards the end of the twenty-first century are small to moderate, with the largest signals being a poleward shift in the annual mean and extreme significant wave heights in the mid-latitudes of both hemispheres, more pronounced in the Southern Hemisphere, and most likely associated with a corresponding shift in mid-latitude storm tracks. These changes are broadly consistent with results from the few studies available so far. The projected changes in the mean wave periods, associated with the changes in the wave climate in the mid to high latitudes, are also shown, revealing a moderate increase in the equatorial eastern side of the ocean basins. This study presents a step forward towards a larger ensemble of global wave climate projections required to better assess robustness and uncertainty of potential future wave climate change.
IMPACT OF GLOBAL CLIMATE CHANGE ON WAVE CLIMATE
Proceedings of Coastal Dynamics 2009 - Impacts of Human Activities on Dynamic Coastal Processes, 2009
The influence of global climate change due to green house effects on the earth environment will be required impact assessment, mitigation and adaptation strategies for future our society. This study predicts future ocean wave climate in comparison with present wave climate based on the atmospheric general circulation model and global wave model. The annual averaged and extreme sea surface winds and waves are analyzed in detail. There are clear regional dependence of annual average and extreme value from present to future climate. The wind speeds and wave heights of future climate are increased in middle latitudes and the Antarctic ocean, and these are decreased in the equator. The annual averaged winds and waves are decreased off coast of Japan but their maxima are increased than those of present climate.
Projection of Extreme Wave Climate Change under Global Warming
Hydrological Research Letters, 2010
The influence of global climate change due to greenhouse effects on the earth's environment will require impact assessment, mitigation and adaptation strategies for the future of our society. This study predicts future ocean wave climate in comparison with present wave climate based on the atmospheric general circulation model and global wave model. The annual averaged and extreme sea surface winds and waves are analyzed in detail. There are clear regional dependences of both annual average and also extreme wave height changes from present to future climates. The wave heights of future climate will increase at both middle latitudes and also in the Antarctic Ocean, with a decrease at the equator.
Ocean Modelling, 2013
A global 1°implementation of the spectral wave model, WaveWatch III, was forced with surface winds from two atmosphere-ocean general circulation models (AOGCMs: ECHAM5 and CSIRO Mk3.5), dynamically downscaled to 60 km using the Cubic Conformal Atmospheric Model. Two 30-yr time slices were simulated: 1979-2009 representing current climate, and 2070-2099 representing a future climate scenario under a high greenhouse gas emission scenario (SRES A2). A further wave model simulation with forcing from the NCEP Climate Forecast System Reanalysis for 1979-2009, using the same model settings as the climate model forced runs, serves as a benchmark hindcast to assess skill of climate-model-derived wave fields. Climate model forced wave simulations for the 1979-2009 time-slice display biases relative to the benchmark wave climate -notably an overestimation of wave generation in the Southern Ocean, which influences broad regions of the Pacific which receive these waves as swell. Wave model runs were repeated following bias-adjustment of the climate model forcing winds with the aim to reduce biases, but model skill to simulate the monthly 99th percentile of significant wave heights deteriorates severely.
Ocean Engineering, 2013
This study analyzes future changes in average upper ocean physics such as sea level rise, sea surface winds and ocean wave heights by using a climate data set combining IPCC (2007) results and the latest high-resolution atmospheric general circulation model results from the Meteorological Research Institute, Japan. Ocean wave height H s is statistically projected by using multi-model ensemble method based on an empirical formula as a function of sea surface winds. The ensemble means and the standard deviations of upper ocean physics, which can be used in coastal and ocean engineering, are projected for the period between 2000 and 2100. The magnitude of the ratio of future changes in H s to the value in the present climate is at most 7 15%, which exceeds the projected changes in sea surface pressure and surface wind speed, U 10 . A large uncertainty in the projected H s can be observed around the Equator and in the Antarctic Ocean. The synoptic scale of atmospheric pressure distribution is found to be important for estimating and understanding the future changes in sea level rise, U 10 and H s .
Climate change impact on North Sea wave conditions: A consistent analysis of ten projections
Ocean Dynamics, 2015, 65, 255–267, 2015
Long-term changes in the mean and extreme wind wave conditions as they may occur in the course of anthropogenic climate change can influence and endanger human coastal and offshore activities. A set of ten wave climate projections derived from time slice and transient simulations of future conditions is analyzed to estimate the possible impact of anthropogenic climate change on mean and extreme wave conditions in the North Sea. This set includes different combinations of IPCC SRES emission scenarios (A2, B2, A1B and B1), global and regional models and initial states. A consistent approach is used to provide a more robust assessment of expected changes and uncertainties. While the spatial patterns and the magnitude of the climate change signals vary, some robust features among the ten projections emerge: mean and severe wave heights tend to increase in the eastern parts of the North Sea towards the end of the twenty-first century in nine to ten projections, but the magnitude of the increase in extreme waves varies in the order of decimeters between these projections. For the western parts of the North Sea more than half of the projections suggest a decrease in mean and extreme wave heights. Comparing the different sources of uncertainties due to models, scenarios and initial conditions it can be inferred that the influence of the emission scenario on the climate change signal seems to be less important. Furthermore, the transient projections show strong multidecadal fluctuations, and changes towards the end of the twenty-first century might partly be associated with internal variability rather than with systematic changes.
Climate Change Impacts on Future Wave Climate around the UK
Journal of Marine Science and Engineering, 2016
Understanding the changes in future storm wave climate is crucial for coastal managers and planners to make informed decisions required for sustainable coastal management and for the renewable energy industry. To investigate potential future changes to storm climate around the UK, global wave model outputs of two time slice experiments were analysed with 1979-2009 representing present conditions and 2075-2100 representing the future climate. Three WaveNet buoy sites around the United Kingdom, which represent diverse site conditions and have long datasets, were chosen for this study. A storm event definition (Dissanayake et al., 2015) was used to separate meteorologically-independent storm events from wave data, which in turn allowed storm wave characteristics to be analysed. Model outputs were validated through a comparison of the modelled storm data with observed storm data for overlapping periods. Although no consistent trends across all future clusters were observed, there were no significant increases in storm wave height, storm count or storm power in the future, at least according to the global wave projection results provided by the chosen model.
Future Wave Conditions of Europe, in Response to High‐End Climate Change Scenarios
Journal of Geophysical Research: Oceans, 2018
Changes in future North Atlantic storminess will impact upon wave conditions along the European coasts, with implications for coastal erosion, overtopping, and flood risk. In this study we make a detailed analysis of historic and future wave conditions around the European Atlantic coast, making projections out to the year 2100 under Representative Concentration Pathways 4.5 and 8.5 future emissions scenarios. A decrease in mean significant wave height of the order 0.2 m is projected across most of the European coast. Increases in the annual maximum and 99th percentile wave height as large as 0.5-1 m are observed in some areas but with a more complex spatial pattern. An increase in waves to the north of Scotland is also observed, mainly caused by a reduction in sea ice. We generate a set of coastal wave projections at around 10-km resolution around continental Europe, Ireland, and the British Isles. Widening of the probability density function (PDF) is observed, suggesting an increased intensity of rare high wave events in the future. The emergent signal of a reduced mean wave height is statistically robust, while the future changes in extreme waves have a wider confidence interval. An assessment of different extreme waves metrics reveals different climate change response at very high percentiles; thus, care should be taken when assessing future changes in rare wave events. Plain Language Summary Waves are important to shipping, coastal flooding, and erosion. A numerical model of waves was built and tested for skill in representing historic waves, by comparing against observations at buoys. Climate model winds were then used to drive a model of sea surface waves. The future projections show a decrease in average wave height but increases in the maximum waves. The statistical method used to measure extreme waves seen during storms can affect the conclusion. We see evidence that the mean can go down, while the extremes increase in future.
2008
The effect of global climate change on the wave climate of the coastal regions of the UK is investigated. A state of the art third generation wave model is used to predict changes in wave climate in the North East Atlantic and UK coastal waters. The driving meteorological data is provided by global and regional climate models, driven by different future greenhouse gas emissions scenarios. Present day wave climates are validated against a previous hindcast, which has been calibrated with wave observations, and good agreement is found in regions of interest. These studies downscale the affect of global climate changes on wave climate to a previously unresolved scale. Ouput of these wave climate predictions are to be used in a regional Coastal Simulator manged by the Tyndall Centre for Climate Change Research. The Coastal Simulator is a framework of integrated hydrodynamic, morphological and socio-economic models that provides predictions of the increased risks of coastal flooding and cliff erosion on the East Anglia coastline. The drivers of increased risks are sea-level rise and increased storm surges and waves in possible future climate scenarios. On a large scale, for the range of future climate scenarios, strong positive changes in significant wave height are predicted in the North East Atlantic and South West of the UK. On the regional scale of the Southern North Sea the spatial pattern of changes in wave height varies considerably with possible future scenario, but positive changes in the mean and high percentiles of wave height are predicted off-shore from the particular region of interest on the East Anglia coastline. 132 132 132