不同城市冠层模式对城市地表能量平衡模拟能力的检验

The validation on the simulation performance of different urban canopy models for urban surface energy balance

城市地表能量平衡过程是城市大气边界层数值模式的关键过程之一,但对目前不同参数化的适用性和模拟性能评估工作较少.利用2013年南京市中心市区的湍流热通量的观测数据与单层冠层模式(Single Layer Urban Canopy Model,SLUCM)、局地气象参数化方案(Local-scale Urban Meteorological Parameterization Scheme,LUMPS)、城市能量和水平衡方案(Surface Urban Energy and Water Balance Scheme,SUEWS)以及公用陆面模式城市参数化方案(the Community Land Model Urban,CLMU)这四个模式的模拟结果进行对比分析.分析表明:(1)在能量平衡各项中,各模式对于净辐射的模拟颇好,其均方根误差普遍低于感热项的50%,潜热和储热项模拟较差.(2)各模式对净辐射均有低估,其中SLUCM模式模拟最佳,全年平均偏差约7.7%,其均方根误差10~20Wm-2左右;对于感热通量,SUEWS模式模拟较好,日间偏差低于7%;对于潜热通量,则是CLMU模式更佳,特别是夏秋冬三季,平均偏差约12.5%;对于储热项,SLUCM模拟较优,偏差低于10%,各季均方根误差也普遍低于其他模式的50%.(3)各模式普遍表现为:秋冬两季模拟优于春夏两季,夜间模拟比日间更佳.比较结果为数值模拟中城市冠层模式的选取与改进提供了参考依据.

The simulation of urban surface energy balance process is one of the key processes of urban atmospheric boundary layer numerical model.Nevertheless,there＇s less work for applicability and simulation performance towards different parameterization at present.We compare the simulation results of different urban parameterization schemes consisting of the Single Layer Urban Canopy Model（SLUCM）,the Local-scale Urban Meteorological Parameterization Scheme（LUMPS）,the Surface Urban Energy and Water Balance Scheme（SUEWS）and the Community Land Model Urban（CLMU）models with the observed data to analyze their simulated performance for surface energy balance in Nanjing.The results illustrate that：（1）All models have a good performance for thesimulation of the net radiation,the root mean square error is generally lower than 50% of the sensible heat,and the simulations of latent heat and heat storage are poorer.（2）The models underestimates the value of net radiation,among which SLUCM model simulates optimally,the annual deviation is about 7.7%,and the root mean square error is about 10~20 Wm-2.The simulation of SUEWS model is better than other models for sensible heat flux.Its daytime deviation is less than 7%.As for latent heat flux,the performance of CLMU model is excellent,especially in summer,autumn and winter,the average deviation is about 12.5%.the simulation of SLUCM is 10 percent deviating from the observation of the heat storage,which implies its better representation,And it also can be find from the issue that the root mean square error is generally lower than 50% of other models.（3）In general,the simulation in winter and autumn is better than other seasons,and the nighttime characteristics of observed heat flux are more optimal reproduced comparing with daytime performance by models.The results of this paper provide a reference for the selection and improvement of urban canopy model in numerical simulation.