Projection of Extreme Wave Climate Change under Global Warming (original) (raw)
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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 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.
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...
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.
Assessment of Future Wave Climate on basis of Wind-Wave- Correlations and Climate Change Scenarios
Consequences resulting from future climate change may be one of the most severe threats for people and economies in many countries of the world. With respect to coastal protection, the resulting changed hydrodynamic impacts are discussed globally. At present, IPCC (2007) is estimating a world-wide average sea level rise of less than 1.0m within the 21st century. Other sources (e.g. Rahmstorf & Schellnhuber, 2007) which are taking into account possible melting of the two main continental ice covers (Greenland and Antarctica), estimate significantly higher values especially over long periods. Besides the problem of sea level rise, also possible general changes of the local wave conditions are described. The model results indicate a small increase of the overall wave energy input for the future and a more significant change in the wave directions where westerly wave conditions may increase by 3.5% compared to the actual conditions.
Climate change impact on extreme wave conditions in the North Sea: an ensemble study
Ocean Dynamics, 2008
An analysis of today's mean and extreme wave conditions in the North Sea and their possible future changes due to anthropogenic climate change are presented. The sea state was simulated for the 30-year period 2071-2100 using the wave model WAM and an ensemble of wind field data sets for four climate change realizations as driving data. The wind field data sets are based on simulation outputs from two global circulation models (GCMs: HadAM3H and ECHAM4/ OPYC3) for two emission scenarios (A2 and B2, Intergovernmental Panel on Climate Change, Special Report on Emission Scenarios). They were regionalized by the Swedish Meteorological and Hydrological Institute using the regional climate model RCAO. The effects of the climate realizations on the sea state statistics were assessed by analysing the differences between the patterns in the four CGM/emission scenario combinations and those in two control simulations representing reference wave climate conditions for the 30-year period .
Future wave climate change under global warming : Ensemble projections
2021
Waves at the ocean surface are responsible for modulating the exchange of radiation, heat, mass and momentum between the atmosphere and the ocean. Waves also play an important role in engineering and environmental related issues, such as coastal erosion, coastal flooding, and sea level extremes, representing a major hazard for any offshore structure or operation. The impact of climate change on ocean waves is therefore of paramount importance. This thesis investigates projected changes in future wave climate as a response to global warming, through a large set of simulations (ensembles), towards the end of the 21st century. The wave climate ensembles are subjected to a strict evaluation process, through comparison with reanalyzes, hindcasts and in-situ observations, to ascertain their ability to simulate the historical wave climate. Bias correction methods are implemented, to deal with the systematic errors found between the simulated and reference data sets, ultimately generating n...
Monthly Variations of Global Wave Climate due to Global Warming
Jurnal Teknologi, 2015
Over recent years, ocean wave climate change due to global warming has attracted a lot of attention not only coastal and offshore engineer but also stakeholders in the marine industry. There is a wide range of application in ocean environment that require information on ocean wave climate data, such as ships design, design of offshore platforms and coastal structures or naval industry. In this research, monthly variation in significant wave height is studied using MRI-AGCM3.2 wind climate data for 25 year period from 1979-2003. The 25 year significant wave height simulation derived from JMA/MRI-AGCM wind climate data. The JMA/MRI-AGCM climate data were input into WAM model. The results showed that the monthly variability of significant wave height in the Northern Hemisphere is greater than in the Southern Hemisphere. Meanwhile, most of the equatorial regions are in calm condition all year.
Modelling the effect of climate change on the wave climate of the world’s oceans
Ocean Science Journal, 2012
This paper analyses the trends and the future projections of significant wave height in several ocean areas at different parts of the world. It uses a stochastic Bayesian hierarchical space-time model, with a regression component with atmospheric levels of CO 2 as covariates in order to estimate the expected long-term trends and make future projections towards the year 2100. The model was initially developed for an area in the North Atlantic ocean, and has been found to perform reasonably well there, and it is now investigated how the model performs for other ocean areas. 11 new ocean areas have been analysed with the model, and this paper presents the results pertaining to the estimated long-term trends and future projections of monthly maximum significant wave height for each of the 12 ocean areas.
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 .