Wave Characteristics And Wave Energy Prediction In The East China Sea

With the rapid development of economy,human beings rely more and more on fossil energy.However,the use of fossil energy is often accompanied by the excessive emission of greenhouse gases,which makes the phenomenon of global warming more serious,and human’s living environment is facing severe challenges.Compared with the disadvantages of traditional energy,such as pollution to the environment and nonrenewable,new energy has the advantages of lower pollution to the environment,less emissions and sustainability.Therefore,countries begin to focus on clean energy such as wind energy,solar energy and wave energy,which can be widely used,and in-depth study on its development and utilization,among which wave energy is regarded as one of the most important green energy with its advantages of strong predictability,high utilization rate and low environmental impact.Under the background of global warming and sea level rise caused by massive emissions of greenhouse gases,wave characteristics have changed significantly in various coastal regions of China.Therefore,new strategies for wave energy utilization and development have been put forward.In order to meet this demand,this paper mainly studies the change of wave characteristics under different greenhouse gas emission scenarios.There are differences in wave height,period,50-year and 100-year extreme wave height and wave energy distribution under different greenhouse gas emission scenarios.In this paper,based on the Representative Concentration Pathway,Regional highprecision wave downscaling Reanalysis results under RCP)8.5 emission scenario and wave analysis data from 1979-2022 based on ECMWF Reanalysis v5 ERA5,A comparative analysis of data based on a future period of high emissions(2021--2050)and a historical period(1979--2022)was conducted to explore the effects of climate change on waves in the Bohai,Yellow and East China Seas.(1)The study found that the average annual wave height distribution of 1979-2022 was not much different from that of 2021-2050 under RCP8.5,and the overall seasonal mean wave height distribution was high in summer,autumn,winter and low in spring,which was roughly similar to the seasonal distribution of 1979-2022.However,under the RCP8.5 emission scenario,the average annual and seasonal wave height,cycle and wave energy are generally higher than in the past 44 years.(2)There is little difference in the distribution of annual average cycle under different greenhouse gas emission scenarios.The overall distribution of annual average cycle in the study area is larger in summer,autumn,winter and smaller in spring.Under the RCP8.5 emission scenario,the average annual cycle of the study area is mostly higher than that of 1979-2022.Under the RCP8.5 emission scenario,the average annual cycle of the East China Sea in summer,autumn and winter increases significantly compared with that of 1979-2022.(3)Under the RCP8.5 emission scenario,the average annual wave energy in Bohai Sea has little difference from that in the past 44 years,and the wave energy in the southwest of Bohai Sea increases slightly under the RCP8.5 scenario.The average annual wave energy in the Yellow Sea increases gradually from north to south,and its average annual wave energy ranges from 5 to 10KW/m.The average annual wave energy in the East China Sea increases significantly compared with the past 44 years based on the RCP8.5 emission scenario,and the maximum wave energy in the East China Sea can reach more than 25KW/m under the RCP8.5 scenario.(4)Based on the conditions conducive to wave energy collection by wave energy collection devices,such as wave energy level,topographic water depth conditions,effective wave height and coefficient of variation,this paper evaluates the most suitable area for wave energy utilization in the study area.In this paper,the water depth is less than 100 m,the effective wave height is between 1 and 4m,the probability of occurrence is more than 60%,the average annual wave energy variation coefficient is mostly around 1 and the average annual wave energy is between 10 and 25KW/m,as the key development and utilization area of wave energy.To sum up,the paper selects the area with the longitude and latitude of(122.5°E,30.85°N),(127.75°E,30.58°N),(120.9°E,24.5°N),and(118.65°E,24.5°N)are designated as key development zones for wave energy utilization.