The Characteristics Of Spatiotemporal Distribution Of Wind Energy Along The Coastal Line Of China And The Numerical Simulation On The Impact Factors

The amount of the wind energy that can be utilized is very large in the coastal area due to its special environment. The long coastal line along the east edge of China mainland means it is worthy of studying on the spatiotemporal distribution of coastal wind energy and the corresponding impact factors. Firstly, we use the reanalysis data with horizontal resolution of 0.75°0.75° from the European Center of Medium-range Weather Forecast (ECMWF) to investigate the wind energy and wind speed in the narrow area along the coastal line of China. Discussions focus on the characteristics of the distribution of the wind energy and wind speed in different regions and different seasons. We also compare the results yielded by two different algorithms of wind energy and analyze the dynamical and thermal factors that may have impacts on the form of the spatiotemporal distribution of wind energy. Secondly, the Weather Research Forecast model (WRF) is used to study influence of the increasing of sea surface temperature (SST) and the developing of urban the wind energy in the coastal area of China. Several conclusions are drawn as follows, in the light of diagnosis and numerical simulation.(1) Significant differences are found for the spatiotemporal distribution of coastal wind energy and wind speed in different regions and seasons. Firstly, the wind energy is significantly larger in coastal area than in its adjacent inland, with the former about twice as large as the latter. Secondly, the seasonal distribution of coastal wind energy among different regions shows clear difference. The wind energy in spring in Bohai gulf is clearly larger than that in other regions (the East of China, the Southeast of China and the north of South China Sea) while this situation reverses in summer. The seasonal difference for the wind energy in the coastal area of east China is not as significant as the other regions. The wind energy in summer in the coastal area of east China is slightly but clear larger than the other regions. For the coastal area of southeast China and the north of South China Sea (SCS), the wind energy is significantly larger in autumn and winter. The annual tendency of the variance of wind speed also shows clear difference for different regions.(2) The seasonal mean of wind speed in coastal area is over 3 m s-1 for all years. The wind energy in autumn and winter is more powerful than that in spring and summer, especially for summer when the wind energy is only a half of that in winter. The annual variance of wind speed is clearly different for different regions, but it is still small when it is compared to the amount of wind speed itself.(3) For any region of the east coast of China, it can be found some relationships between the intense of coastal wind energy and the distance (between this region and the source area of wind energy), or the component of the gradients of pressure and temperature mapped on the seasonal mean direction of wind. The longer the distance is, the weaker the intense of wind energy is. The larger seasonal mean wind speed usually accompanies with the larger component of gradients of pressure and temperature mapped on the wind direction. The closely relationship between the spatial distribution of pressure and temperature in the narrow band along coastal line of China and the spatial distribution of wind speed indicates that human activities, such as urbanization, can influence the spatial distribution of wind energy.(4) Numerical simulations show that the increasing of SST has great impacts on the wind speed in summer and autumn. The wind speed will increase as the SST increase in all coastal area in summer, while it only increase in Southeast of China and south of East of China. The urbanization results in the larger force of fraction, causing the weakening of cyclones influence China.