Spatial and seasonal variations of secondary organic aerosol from terpenoids over China

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• 作者：Xiang Ding ; Yu‐Qing Zhang ; Quan‐Fu He ; Qing‐Qing Yu ; Ru‐Qin Shen ; Yanli Zhang ; Zhou Zhang ; Su‐Jun Lyu ; Qi‐Hou Hu ; Yue‐Si Wang ; et al
• 刊名：Journal of Geophysical Research: Atmospheres
• 出版年：2016
• 出版时间：27 December 2016
• 年：2016
• 卷：121
• 期：24
• 页码：14,661-14,678
• 全文大小：2.6MB
• ISSN：2169-8996

文摘

A majority of global secondary organic aerosol (SOA) comes from terpenoids. In this study, we carried out a 1 year nationwide observation of pinenes (α- and β-pinene) and SOA tracers from monoterpenes (SOA_M) and β-caryophyllene (SOA_C) over China for the first time. SOA_M and SOA_C tracers ranged from 9.80 to 49.0 ng m⁻³ and 1.72 to 7.72 ng m⁻³, respectively, with high levels in southern China. Pinenes ranged from 34 to 102 parts per trillion by volume, with α-pinene dominant over β-pinene. SOA_M tracers were correlated between paired sites, suggesting a regional impact of SOA_M, while pinenes were uncorrelated between sites due to their rapid oxidation. High levels of SOA_M tracers were observed in spring and summer. However, at the Hailun site in Northeast China, SOA_M tracers increased during winter. The positive correlation between SOA_M tracers and the biomass burning (BB) tracer levoglucosan during winter at Hailun indicated that the unexpected increase of SOA_M was associated with BB. The SOA_C tracer, β-caryophyllenic acid, increased during winter and was positively correlated with levoglucosan, suggesting substantial contributions from BB to SOA_C production in wintertime. Together with SOA tracers from isoprene, these tracers were applied to estimate biogenic secondary organic carbon (BSOC) from isoprene, monoterpenes, and β-caryophyllene. The annual average BSOC was 0.91 ± 0.41 μgC m⁻³,with the majority from monoterpenes and the highest level in Southwest China. BSOC was elevated from April to September and was lowest in January and February. BSOC composition dramatically changed from a monoterpene majority in fall-spring to an isoprene majority in summer.