气候变化领域集成服务门户(CCPortal): Shipborne measurements of total OH reactivity around the Arabian Peninsula and its role in ozone chemistry

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DOI	10.5194/acp-19-11501-2019
	Shipborne measurements of total OH reactivity around the Arabian Peninsula and its role in ozone chemistry
	Pfannerstill E.Y.; Wang N.; Edtbauer A.; Bourtsoukidis E.; Crowley J.N.; Dienhart D.; Eger P.G.; Ernle L.; Fischer H.; Hottmann B.; Paris J.-D.; Stönner C.; Tadic I.; Walter D.; Lelieveld J.; Williams J.
发表日期	2019
ISSN	16807316
起始页码	11501
结束页码	11523
卷号	19 期号:17
英文摘要	The Arabian Peninsula is characterized by high and increasing levels of photochemical air pollution. Strong solar irradiation, high temperatures and large anthropogenic emissions of reactive trace gases result in intense photochemical activity, especially during the summer months. However, air chemistry measurements in the region are scarce. In order to assess regional pollution sources and oxidation rates, the first ship-based direct measurements of total OH reactivity were performed in summer 2017 from a vessel traveling around the peninsula during the AQABA (Air Quality and Climate Change in the Arabian Basin) campaign. Total OH reactivity is the total loss frequency of OH radicals due to all reactive compounds present in air and defines the local lifetime of OH, the most important oxidant in the troposphere. During the AQABA campaign, the total OH reactivity ranged from below the detection limit (5.4 s-1) over the northwestern Indian Ocean (Arabian Sea) to a maximum of 32:8±9:6 s-1 over the Arabian Gulf (also known as Persian Gulf) when air originated from large petroleum extraction/processing facilities in Iraq and Kuwait. In the polluted marine regions, OH reactivity was broadly comparable to highly populated urban centers in intensity and composition. The permanent influence of heavy maritime traffic over the seaways of the Red Sea, Gulf of Aden and Gulf of Oman resulted in median OH sinks of 7.9-8.5 s-1. Due to the rapid oxidation of direct volatile organic compound (VOC) emissions, oxygenated volatile organic compounds (OVOCs) were observed to be the main contributor to OH reactivity around the Arabian Peninsula (9 %-35 % by region). Over the Arabian Gulf, alkanes and alkenes from the petroleum extraction and processing industry were an important OH sink with ∼ 9 % of total OH reactivity each, whereas NOx and aromatic hydrocarbons (∼ 10 % each) played a larger role in the Suez Canal, which is influenced more by ship traffic and urban emissions. We investigated the number and identity of chemical species necessary to explain the total OH sink. Taking into account ∼ 100 individually measured chemical species, the observed total OH reactivity can typically be accounted for within the measurement uncertainty (50 %), with 10 dominant trace gases accounting for 20 %-39 % of regional total OH reactivity. The chemical regimes causing the intense ozone pollution around the Arabian Peninsula were investigated using total OH reactivity measurements. Ozone vs. OH reactivity relationships were found to be a useful tool for differentiating between ozone titration in fresh emissions and photochemically aged air masses. Our results show that the ratio of NOx- and VOC-attributed OH reactivity was favorable for ozone formation almost all around the Arabian Peninsula, which is due to NOx and VOCs from ship exhausts and, often, oil/gas production. Therewith, total OH reactivity measurements help to elucidate the chemical processes underlying the extreme tropospheric ozone concentrations observed in summer over the Arabian Basin. © 2019 Author(s).
语种	英语
scopus关键词	air quality; atmospheric chemistry; atmospheric pollution; hydroxide; oil production; oxidation; ozone; pollutant source; volatile organic compound; Arabian Peninsula; Arabian Sea; Indian Ocean; Indian Ocean (Northwest); Iraq; Kuwait [Middle East]; Persian Gulf
来源期刊	Atmospheric Chemistry and Physics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/144155
作者单位	Atmospheric Chemistry and Multiphase Chemistry Departments, Max Planck Institute for Chemistry, Mainz, 55128, Germany; Laboratoire des Sciences du Climat et de l'Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, France; Energy Environment and Water Research Center, Cyprus Institute, Nicosia, Cyprus
推荐引用方式 GB/T 7714	Pfannerstill E.Y.,Wang N.,Edtbauer A.,et al. Shipborne measurements of total OH reactivity around the Arabian Peninsula and its role in ozone chemistry[J],2019,19(17).
APA	Pfannerstill E.Y..,Wang N..,Edtbauer A..,Bourtsoukidis E..,Crowley J.N..,...&Williams J..(2019).Shipborne measurements of total OH reactivity around the Arabian Peninsula and its role in ozone chemistry.Atmospheric Chemistry and Physics,19(17).
MLA	Pfannerstill E.Y.,et al."Shipborne measurements of total OH reactivity around the Arabian Peninsula and its role in ozone chemistry".Atmospheric Chemistry and Physics 19.17(2019).