兰州市榆中县城区重气示踪试验的初步分析  

Preliminary analysis of heavy gas tracer transport and difusion within an urban area in Yuzhong County, Lanzhou

作　　者：董龙翔[1] 左洪超[1] 董文成[1] 

机构地区：[1]兰州大学大气科学学院,兰州730000

出　　处：《兰州大学学报（自然科学版）》2013年第5期644-650,共7页Journal of Lanzhou University(Natural Sciences)

基　　金：国家重点基础研究发展计划(973计划)项目(2011GB706900)

摘　　要："城市气象/示踪试验"在中国西北甘肃省榆中县的城市区域内(3 km×3 km)构建了一个精细化的观测网,对气象场和示踪物浓度场进行了高时空分辨率的观测.利用观测资料初步分析了城区内流场及示踪物的输送扩散特征.结果表明:受不同尺度运动相互作用的影响,城区流场十分复杂;城市冠层顶风场与示踪物浓度场有较好的对应,即浓度高值区基本出现在主导风向下风方向±20的扇形区域内且呈现出近似为正态分布的特征,同时地面和城市冠层顶示踪物的浓度分布存在明显差异.The Urban Meteorological and Tracer Experiment was carried out within a 3 km ×3 km urban region in Yuzhong County, Lanzhou. Both the meteorological and the tracer concentration fields were observed with a high spatiotemporal resolution during the experiment. Characteristics of wind field and tracer diffusion within the urban area were analyzed. The results show that, due to the interaction between motions with different scales, the flow field within the urban area was very complex. Tracer concentrations matched well with the wind field above urban canopy layer （UCL）, with high tracer concentrations appearing downwind of the predominant wind within a sector of ±20° around the main wind direction and approximate normal distribution in crosswind direction. The ground distribution of tracer concentrations was significantly different from that above the UCL.

关 键 词：城市冠层 城区流场 输送扩散 示踪试验 

分 类 号：X16[环境科学与工程—环境科学]