环渤海区域风能资源WRF同化模拟及特征分析

利用WRF模式及其3DVAR同化模块，结合环渤海区域风能资源观测网测风塔观测数据，设计并构建了多种3DVAR 同化方案，用来提高环渤海区域风能资源数值模拟初始场质量。以2010 年4 月12 日至13 日一次大风过程为研究对象，利用该同化方案进行了一系列WRF数值模拟对比试验。选择较优的3DVAR同化方案对环渤海区域70 m高度风能资源进行了2009 年6 月1 日至2010 年5 月31 日一整年的数值模拟。模拟结果表明，较优的3DVAR同化方案能有效地改进区域风能资源数值模拟初始场质量，主要体现在模拟值与实测值更为接近，模拟效果得到显著改善。环渤海区域70 m高度年平均风速和年平均风功率密度呈现出南小北大的分布特征，渤海中部和北部风能较大，沿垂直于海岸线向内陆方向，风能参数急剧减小。

WRF 3DVAR Data Assimilation Numerical Simulation and Analysis ofWind Energy Resources over Bohai Sea Region

From the view of improving initial conditions of wind energy resources over Bohai Sea region and using the data of wind tower network over the same region, a 3DVAR data assimilation scheme is designed based on WRF model and its 3DVAR module. By using this scheme, a series of WRF numerical experiments of a strong wind event over the Bohai Sea from 12 to 13 April, 2010 was conducted to evaluate its performance. By selecting the optimal 3DVAR assimilation scheme, one year's WRF numerical simulation of 70 m height wind energy resources over Bohai Sea region between June 1, 2009 to May 31, 2010 was conducted. The results show that the annual average wind speed between measured values and analog values can obviously decrease by using YSU PBL scheme. The optimal WRF numerical model and 3DVAR assimilation can simulate the change regulation of the 70 m height hourly average wind speed in Bohai Sea region. The absolute error and relative error of average wind speed after wind tower data assimilation are smaller than before its assimilation and simulation of hourly wind speed approach observation. The annual average wind speed difference between simulation and observation of each wind tower is no more than 1.5 m/s and wind speed difference of eight wind towers is over 1.0 m/s, meanwhile wind speed difference of more than ten wind towers are below 0.5 m/s. The relative error of annual average wind speed between simulation and observation of all wind towers is 11.3%, of which 12 wind towers'are below 10.0% and three wind towers' are over 20.0%. The 70 m height annual average wind speed and wind power density over Bohai Sea region are showed small in southern part and large in the northern and the wind energy resources of central and northern Bohai Sea are higher than others. The wind speed trends is smaller in Bohai Sea but the inland wind speed affected by terrain changes dramatically. Distribution of the wind energy parameter is obviously affected by coastline and it decreases sharply along inland direction.