城市冠层过程的研究与进展

DEVELOPMENT OF RESEARCH ON URBAN CANOPY PARAMETERIZATION SCHEME

介绍了城市冠层过程研究的概况和历史,概括了城市冠层的特征及其作用于局地气候和中尺度系统的主要方式,总结了城市冠层参数化方案或模式的研究进展。比较了几种参数化方法和模式的特点,提出目前存在的一些问题。认为:现有的参数化方案和模式尚未能完整体现城市下垫面特征、准确反映人类活动影响,二者的发展有赖于对城市下垫面建筑特征更合理、细致地描述,对人为热量、水汽影响更准确的估计与刻划。与局地因素密切相关的城市冠层模式还需要更多地在模式中引入局地差异影响。同时指出,要提高耦合城市过程的中尺度模式预报水平,需要相应改进包括云、降水、次网格地形及边界层动力学等的参数化。

General situation and history of research on urban canopy process have been introduced in this paper. The main approaches that urban canopy affects the regional climate and mesoscale systems have been concluded. The developments of urban canopy model and parameterization schemes were summarized. Furthermore, characteristics of these models and parameterization schemes were compared. The existing problems in the current urban canopy models and parameterization were put up. The paper drew the conclusion that current models and parameterization schemes do not make complete description of buildings＇ characteristics and proper evaluation of human activity. The future development in model and parameterization will rely on the improvements in the two aspects. More parameters that are related to local traits （such as topographic characteristic） should be introduced in urban canopy models. It is also pointed out that to raise forecasting accuracy of models, improvements on parameterization of boundary processes （in the coupled mesoscale model） including cloud, precipitation and sub-grid terrain are needed.