陆面参数的优化改进及其对空气质量模拟的影响

陆-气交换过程是影响大气环境数值模式性能的关键点之一，而其中陆面参数的设定又是合理、准确再现复杂下垫面陆-气交换过程的重点。目前在大气环境模式中，许多陆面过程的参数（粗糙度长度Z0、城市分数项、城市形态参数等）都是作为常数处理，没有体现出时空差异性。本研究将致力：1）利用卫星遥感数据及城市规划勘测的城市结构数据，结合形态学方法改进广东省范围内主要植被及城市下垫面类型的Z0参数；2）选择城市形态复杂的超大城市（如广州），利用城市结构数据制作非均匀分布的城市分数项以及城市形态参数并耦合进城市冠层方案中；3）结合细化的排放清单、污染物监测数据及加强试验“走航车”立体监测数据，在模式模拟与验证的基础上，定量计算优化改进后的参数对空气质量模拟的影响。一方面探讨陆面参数对动力、热力、污染物浓度及污染物沉降汇过程的影响机制，另一方面为提升模式性能提供一定的技术支撑。

One of the most important things for numerical model performance is to reproduce the land-air exchange process reasonably and accurately, especially the setting of various land surface parameters. In most numerical models, a lot of land surface parameters, including roughness length (Z0), urban fraction (UF), urban morphology (UM) (building height and width), are all calculated as constants. That is to say, there is no space-time difference in the model for these parameters. This project will focus on: 1) Combined with the satellite data, building morphology data and observation data, and based on the morphological method, the localized Z0 data of vegetation and urban underlying surface will be established. 2) Choose super city with complex urban morphology (like Guangzhou), the detailed urban building data will be used to establish heterogenic UF and UM data which will be coupled in urban canopy scheme. 3) The refined emission data, air quality observations and the additional data from guided vehicle will be utilized to validate the model simulation results. And then the impacts of localized Z0, UF and UM parameters will be calculated through the numerical simulation model. On the one hand, the influence mechanism of land surface parameters to the local dynamics, thermal, air pollutant concentration fields and pollutant deposition processes will be discussed. On the other hand, this research can provide technological support for improving the model performance.