A Two-Decade Anthropogenic and Biogenic Isoprene Emissions Study in a London Urban Background and a London Urban Traffic Site
A Two-Decade Anthropogenic and Biogenic Isoprene Emissions Study in a London Urban Background and a London Urban Traffic Site
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DOI：
10.3390/atmos9100387
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发表时间：
2018-10-01
期刊：
影响因子：
2.9
通讯作者：
Shallcross, Dudley E.
中科院分区：
文献类型：
--
作者：
Khan, M. Anwar H.;Schlich, Billie-Louise;Shallcross, Dudley E.
建立了异戊二烯和1，3-丁二烯混合比之间的关系，以分离20年（1997-2017年）来在城市背景（埃尔瑟姆）和城市交通（马里波恩路）地区伦敦空气中测得的异戊二烯的人为和生物组分。在此期间的平均白天生物异戊二烯混合比达到0.09 +/- 0.04 ppb（马里波恩路）和0.11 +/- 0.06 ppb（埃尔瑟姆）之间的6：00至20：00当地标准时间，占总白天异戊二烯混合比的40%和75%。发现1997-2017年的平均夏季生物异戊二烯混合比为0.13 +/- 0.02和0.15 +/- 0.04 ppb，分别占Marylebone Road和埃尔瑟姆夏季异戊二烯混合比的50%和90%。显着的人为异戊二烯混合比发现在夜间（0.11 +/- 0.04 ppb）和冬季月份（0.14 +/- 0.01 ppb）在马里波恩路。在高温和高污染事件（高臭氧）期间，有人认为臭氧本身可能直接导致某些异戊二烯排放。通过观察热浪期间生物异戊二烯水平与温度、光合有效辐射和臭氧混合比之间的正相关关系，利用Cobb-Douglas生产函数更好地了解刺激植物异戊二烯排放的非生物因素。臭氧和异戊二烯之间的相关性的其他原因进行了讨论。还观察到城市压力对植被的长期影响，无论持续的生物量水平如何，马里波恩路的生物异戊二烯混合比在20年内都在下降。
A relationship between isoprene and 1,3-butadiene mixing ratios was established to separate the anthropogenic and biogenic fractions of the measured isoprene in London air in both urban background (Eltham) and urban traffic (Marylebone Road) areas over two decades (1997-2017). The average daytime biogenic isoprene mixing ratios over this period reached 0.09 +/- 0.04 ppb (Marylebone Road) and 0.11 +/- 0.06 ppb (Eltham) between the period of 6:00 to 20:00 local standard time, contributing 40 and 75% of the total daytime isoprene mixing ratios. The average summertime biogenic isoprene mixing ratios for 1997-2017 are found to be 0.13 +/- 0.02 and 0.15 +/- 0.04 ppb which contribute 50 and 90% of the total summertime isoprene mixing ratios for Marylebone Road and Eltham, respectively. Significant anthropogenic isoprene mixing ratios are found during night-time (0.11 +/- 0.04 ppb) and winter months (0.14 +/- 0.01 ppb) at Marylebone Road. During high-temperature and high-pollution events (high ozone) there is a suggestion that ozone itself may be directly responsible for some of the isoprene emission. By observing the positive correlation between biogenic isoprene levels with temperature, photosynthetically active radiation and ozone mixing ratios during heatwave periods, the Cobb-Douglas production function was used to obtain a better understanding of the abiotic factors that stimulate isoprene emission from plants. Other reasons for a correlation between ozone and isoprene are discussed. The long-term effects of urban stressors on vegetation were also observed, with biogenic isoprene mixing ratios on Marylebone Road dropping over a 20-year period regardless of the sustained biomass levels.