气候变化领域集成服务门户(CCPortal): Seasonal variation of secondary organic aerosol tracers in Central Tibetan Plateau

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DOI	10.5194/acp-15-8781-2015
	Seasonal variation of secondary organic aerosol tracers in Central Tibetan Plateau
	Shen, R. -Q.; Ding, X.; He, Q. -F.; Cong, Z. -Y.; Yu, Q. -Q.; Wang, X. -M.
通讯作者	Ding, X (通讯作者)
发表日期	2015
ISSN	1680-7316
EISSN	1680-7324
起始页码	8781
结束页码	8793
卷号	15 期号:15
英文摘要	Secondary organic aerosol (SOA) affects the earth's radiation balance and global climate. High-elevation areas are sensitive to global climate change. However, at present, SOA origins and seasonal variations are understudied in remote high-elevation areas. In this study, particulate samples were collected from July 2012 to July 2013 at the remote Nam Co (NC) site, Central Tibetan Plateau and analyzed for SOA tracers from biogenic (isoprene, monoterpenes and beta-caryophyllene) and anthropogenic (aromatics) precursors. Among these compounds, isoprene SOA (SOA(I)) tracers represented the majority (26.6 +/- 44.2 ng m(-3)), followed by monoterpene SOA (SOA(M)) tracers (0.97 +/- 0.57 ng m(-3)), aromatic SOA (SOA(A)) tracer (2,3-dihydroxy-4-oxopentanoic acid, DHOPA, 0.25 +/- 0.18 ng m(-3)) and beta-caryophyllene SOA tracer (beta-caryophyllenic acid, 0.09 +/- 0.10 ng m(-3)). SOA(I) tracers exhibited high concentrations in the summer and low levels in the winter. The similar temperature dependence of SOA(I) tracers and isoprene emission suggested that the seasonal variation of SOA(I) tracers at the NC site was mainly influenced by the isoprene emission. The ratio of high-NOx to low-NOx products of SOA(I) (2-methylglyceric acid to 2-methyltetrols) was highest in the winter and lowest in the summer, due to the influence of temperature and relative humidity. The seasonal variation of SOA(M) tracers was impacted by monoterpenes emission and gas-particle partitioning. During the summer to the fall, temperature effect on partitioning was the dominant process influencing SOA(M) tracers' variation; while the temperature effect on emission was the dominant process influencing SOA(M) tracers' variation during the winter to the spring. SOA(M) tracer levels did not elevate with increased temperature in the summer, probably resulting from the counteraction of temperature effects on emission and partitioning. The concentrations of DHOPA were 1-2 orders of magnitude lower than those reported in the urban regions of the world. Due to the transport of air pollutants from the adjacent Bangladesh and northeastern India, DHOPA presented relatively higher levels in the summer. In the winter when air masses mainly came from northwestern India, mass fractions of DHOPA in total tracers increased, although its concentrations declined. The SOA-tracer method was applied to estimate secondary organic carbon (SOC) from these four precursors. The annual average of SOC was 0.22 +/- 0.29 mu gC m(-3), with the biogenic SOC (sum of isoprene, monoterpenes and beta-caryophyllene) accounting for 75 %. In the summer, isoprene was the major precursor with its SOC contributions of 81 %. In the winter when the emission of biogenic precursors largely dropped, the contributions of aromatic SOC increased. Our study implies that anthropogenic pollutants emitted in the Indian subcontinent could be transported to the TP and have an impact on SOC over the remote NC.
关键词	NAM CO REGION ALPHA-PINENE PHOTOOXIDATION ISOPRENE PM2.5 EMISSIONS MONOTERPENES ATMOSPHERE OXIDATION EPOXIDE
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
WOS类目	Environmental Sciences ; Meteorology & Atmospheric Sciences
WOS记录号	WOS:000359949700014
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/258457
推荐引用方式 GB/T 7714	Shen, R. -Q.,Ding, X.,He, Q. -F.,et al. Seasonal variation of secondary organic aerosol tracers in Central Tibetan Plateau[J]. 中国科学院青藏高原研究所,2015,15(15).
APA	Shen, R. -Q.,Ding, X.,He, Q. -F.,Cong, Z. -Y.,Yu, Q. -Q.,&Wang, X. -M..(2015).Seasonal variation of secondary organic aerosol tracers in Central Tibetan Plateau.ATMOSPHERIC CHEMISTRY AND PHYSICS,15(15).
MLA	Shen, R. -Q.,et al."Seasonal variation of secondary organic aerosol tracers in Central Tibetan Plateau".ATMOSPHERIC CHEMISTRY AND PHYSICS 15.15(2015).