中文摘要：

定量研究城市区域人为CO2通量对于控制温室气体排放具有重要意义,而基于大气CO2浓度观测与大气传输模型方法反演区域尺度的CO2通量是未来的一个重要发展方向,其中模型对大气CO2浓度的模拟则是能否成功反演CO2通量的重要基础,然而我国还未有针对城市区域CO2浓度的长时间（〉1年）模拟.本研究基于高空间分辨率的人为源CO2资料与拉格朗日大气传输模型（WRF-STILT）,对南京市郊区34 m观测高度处2014年大气CO2浓度进行模拟,并就模型模拟结果的主要影响因素和源贡献组成进行了分析,研究得出以下结论：（1）WRF-STILT模型能较好模拟出4个季节观测到的高CO2浓度及有季节差异性的日变化特征.（2）观测CO2浓度的足迹贡献源区（footprint）的季节变化在盛行风向影响下差异巨大,CO2浓度增加值在前1 d的主要贡献占据总浓度贡献的90%,表明该34 m高度观测点可代表长三角区域的CO2排放量的影响,而安徽东部和江苏中南部对其影响更大;（3）相对于排放源的日变化,边界层高度等气象因素的差异是引起CO2强日变化的主要因素,这也是模拟的各季度浓度增加值差异的原因,其中秋季（34.97μmol·mol-1）〉冬季（30.07μmol·mol-1）〉夏季（27.28μmol·mol-1）〉春季（23.36μmol·mol-1）;（4）浓度的主要贡献来源分别为石油生产（41%）和能源工业（26%）,这和长三角区域的人为源CO2排放通量差异巨大（石油生产：3%,能源工业：35%）.

英文摘要：

Quantifying anthropogenic CO2 flux in cities is essential to control greenhouse gas emissions,and the method of combing atmospheric CO2 concentration observations with atmospheric transport model is an important developing direction for CO2 flux retrieval at the regional scale,while the simulation performance of CO2 concentration is a vital basis for this method. Currently,no long-term CO2modeling（ 1 year） has been conducted for urban domains in China. In this study,we applied high spatial resolution anthropogenic CO2 emission inventory and Lagrangian particle dispersion model（ WRF-STILT） to simulate CO2 concentrations observed at 34 m height for the year of 2014,with main focus on the diurnal variations and their controlling factors. Results showed that the WRF-STILT model can simulate peak CO2 concentration and its strong diurnal variation. Seasonal prevailing wind direction difference led to large difference in footprint source area,and 90% of modeled CO2 enhancement was contributed by past one day,which indicated our observations can represent the emission effect of Yangtze River Delta area with main contributions from the east of Anhui province and the west of Jiangsu province. Diurnal variation of boundary layer height had much larger effect than that of emissions,leading to differences in seasonal CO2 enhancement,i.e. autumn（ 34.97 μmol·mol^-1） winter（ 30.07 μmol·mol^-1） summer（ 27.28 μmol·mol-1） spring（ 23.36 μmol·mol^-1）. Source apportionment indicated that oil production and energy industry composed 41% and 26% of CO2 enhancement separately,while it was much different from regional average flux in domain1（ oil production 3% and energy industry 35%） where Yangtze River Delta is located.