深圳市道路交通源温室气体排放特征分析

于2019年9月~2020年7月对深圳市福田区路边的大气CO₂、CH₄、N₂O和CO浓度进行了观测分析.结果显示,其观测时段平均浓度分别为(430.8±6.1)×10^-6、(2318.5±137.9)×10^-9、(332.6±1.6)×10^-9和(333.4±121.2)×10^-9.CO₂与CO浓度的季节变化表现为冬季高、夏季低,CH₄和N₂O浓度的季节变化表现为秋季高、夏季低;在秋冬季浓度较高是由于采暖期的化石燃料排放的远距离输送导致,夏季浓度较低主要是由于远距离传输源的减少以及植物光合作用或光化学反应等汇的增强.CO₂浓度的日变化特征表现为“两峰一谷型”,主要受植物的光合作用、早晚交通高峰等影响;CO浓度的日变化特征表现为“两峰型”,主要受早晚交通高峰的影响;CH₄、N₂O浓度日变化特征都表现为夜间高、日间低,主要受日间光化学反应的影响.将2020年新冠肺炎交通封锁期与2021年同时段进行对比,结果显示大气CO₂、CH₄、N₂O和CO浓度分别降低了3.1%、10.6%、0.5%和13.9%,说明实施交通管控对于促进城市温室气体的减排至关重要.

The characterization of greenhouse gas emission from road traffic sources in Shenzhen

In this study, three greenhouse gases (CO₂, CH₄, and N₂O) and one conventional gas (CO) were observed at a roadside station in Shenzhen from September, 2019 to July, 2020. The average concentration of CO₂, CH₄, N₂O, and CO was (430.8±6.1)x10^-6, (2318.5±137.9)x10^-9, (332.6±1.6)x10^-9, and (333.4±121.2)x10^-9, respectively. Seasonal variation of CO₂ and CO were high in winter and low in summer, Seasonal variation of CH₄ and N₂O were high in autumn and low in summer. The high concentration in autumn and winter is due to the long-distance transmission of fossil fuel emissions during the heating period, and the low concentration in summer is mainly due to the reduction of long-distance transmission sources and the enhancement of sinks such as plant photosynthesis and photochemical reactions. The diurnal variation of CO₂ concentration showed a two-peak and one-valley pattern, which was mainly affected by plant photosynthesis and morning and evening traffic peak; The diurnal variation of CO concentration showed a two-peak pattern, which was mainly affected by the morning and evening traffic peaks. The diurnal variation of CH₄ andN₂O concentration was high at night and low at day, which was mainly affected by daytime photochemical reaction. Among them, the concentration of CO₂ and CO is more sensitive to the emission of traffic sources. In addition, this study compared the COVID-19 lockdown period in 2020 with the same period in 2021, and the results showed that the concentration of CO₂, CH₄, N₂O, and CO decreased by 3.1%, 10.6%, 0.5% and 13.9%, respectively, indicating that traffic control can play an important role in reducing urban greenhouse gas emissions.