Zhang Xue, Hu Ning, Liu Shou-Dong, Wang Shu-Min, Gao Yun-Qiu, Zhao Jia-Yu, Zhang Zhen, Hu Yong-Bo, Lee Xu-Hui, Zhang Guo-Jun
Yale-NUIST Center on Atmospheric Environment, Nanjing University of Information Science & Technology, Nanjing 210044, China.
Collaborative Innovation of Center of Atmospheric Environment and Equipment Technology, Nanjing University of Information Science & Technology, Nanjing 210044, China.
Huan Jing Ke Xue. 2017 Feb 8;38(2):469-475. doi: 10.13227/j.hjkx.201606090.
Urban traffic is an important source of greenhouse gases such as CH. The observations on CH are the basis for quantitative analysis of urban carbon emissions. Taken into consideration the weekly and daily changing characteristics of urban traffic, we conducted experiments to analyze the features of traffic CHemission and its influential factors. The experiments were conducted on 3 main roads in Nanjing on Oct. 17, 18, 20, 23, 2014 with 5 periods of observation per day, and in Nanjing Yangtze River tunnel in the morning and at night of Sep.11 2014. The results showed that:① The average concentration of CH on the urban main road of Nanjing city was greater than that of the background atmosphere. Affected by traffic conditions, the spatial difference of ΔCH concentration was significant on three typical main roads. ΔCH concentration's diurnal variation showed inverted "W" type, and its peak appeared in the morning and evening rush hours. ② Due to the "piston wind" in the tunnel, the CH concentration in Nanjing Yangtze River tunnel gradually increased from the inlet to the outlet and the difference of concentration between the inlet and the outlet was 0.21×10-0.38×10. ③ There was a good linear correlation between CH concentration and CO concentration. The atmospheric ΔCH:ΔCO value of urban main road in Nanjing was 0.0091 and the atmospheric ΔCH:ΔCO value of Nanjing Yangtze River Tunnel was 0.00047-0.0014. ④ Traffic volume and the proportion of natural gas vehicles were the main factors influencing atmospheric ΔCH concentration and ΔCH:ΔCO.
城市交通是甲烷等温室气体的重要排放源。对甲烷的观测是城市碳排放定量分析的基础。考虑到城市交通的周变化和日变化特征，我们开展了实验以分析交通甲烷排放特征及其影响因素。实验于2014年10月17日、18日、20日、23日在南京3条主要道路上进行，每天观测5个时段，并于2014年9月11日早晚在南京长江隧道进行。结果表明：①南京市城市主干道上甲烷的平均浓度高于背景大气浓度。受交通状况影响，三条典型主干道上甲烷浓度的空间差异显著。甲烷浓度的日变化呈倒“W”型，峰值出现在早晚高峰时段。②由于隧道内的“活塞风”，南京长江隧道内甲烷浓度从入口到出口逐渐升高，进出口浓度差为0.21×10 - 0.38×10。③甲烷浓度与一氧化碳浓度之间存在良好的线性相关。南京市城市主干道的大气甲烷与一氧化碳值为0.0091，南京长江隧道的大气甲烷与一氧化碳值为0.00047 - 0.0014。④交通流量和天然气车辆比例是影响大气甲烷浓度和甲烷与一氧化碳比值的主要因素。
