北京夏季晴天边界层特征及城市下垫面对海风影响的数值模拟  

Numerical simulation of characteristics of summer clear day boundary layer in Beijing and the impact of urban underlying surface on sea breeze

作　　者：张亦洲[1,2] 苗世光[2] 戴永久[3] 刘勇洪[4] 

机构地区：[1]北京师范大学地理学与遥感科学学院,北京100875 [2]中国气象局北京城市气象研究所,北京100089 [3]北京师范大学全球变化与地球系统科学研究院,北京100875 [4]北京市气候中心,北京100089

出　　处：《地球物理学报》2013年第8期2558-2573,共16页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目(41175015);国家科技支撑计划项目(2008BAC37B04);公益性行业(气象)科研专项(GYHY200906026)共同资助

摘　　要：对耦合了Noah陆面模式和单层城市冠层模式的WRF(Weather Research and Forecasting)模式系统进行了改进和优化,通过对2010年8月6-7日北京地区晴天个例的模拟试验,检验了优化前后模式系统的模拟能力,分析研究了该个例中城市边界层的特征及日变化.另外,使用优化后的模拟系统通过两组敏感性试验研究了京津城市下垫面对海风的影响.结果表明,优化方案能够显著提高模式系统对该个例的模拟性能,模式系统基本能够模拟出北京夏季边界层的日变化特征,精确的地表使用类型分类等地理信息数据对提高模式预报的准确度有着至关重要的作用,京津城市对海风的发展和推进过程有明显影响,能够阻碍海风的推进、加强风场的水平辐合和垂直上升气流,北京城市下垫面还能在海风到达前增加其强度和推进速度,并在海风经过后延缓其消亡、增加其推进距离.Weather Research and Forecasting （WRF） modeling system coupled with Noah land surface model and single layer urban canopy model was improved and optimized. Performances of the modeling system before and after optmization were examined, and diurnal variation offeatures of urban boundary layer was analyzed, through the numerical study of clear day during 6th and 7th Aug, 2010 over Beijing area. Furthermore, the impacts of urban underlying surface in Beijing and Tianjin on sea breeze were studied through two groups of model sensitivity tests using optimized modeling system. The results show that the optimization can evidently improve the performance of modeling system in the case study in the article. The modeling system can simulate the features of diurnal variation of summer boundary layer in Beijing generally well. Accurate geography data, such as land use and land cover classification information, play a very important role in improving the accuracy of model results. Beijing city and Tianjin city have obvious impacts on the evolution of sea breeze. As the sea breeze penetrating inland, the cities can pose an obstacle to the landward advance of sea breeze current, strengthen the horizontal convergence of wind and vertical updraft. The urban underlying surface in Beijing can also produce faster penetration with stronger intensity of sea breeze before it reaching the city, and increase the lifecycle and inland penetration distance of sea breeze after it passing over the city.

关 键 词：WRF模式 城市冠层模式 城市边界层 城市热岛 海风 

分 类 号：P421[天文地球—大气科学及气象学]