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DOI	10.5194/acp-19-9309-2019
	The sensitivity of PM2.5 acidity to meteorological parameters and chemical composition changes: 10-year records from six Canadian monitoring sites
	Tao Y.; Murphy J.G.
发表日期	2019
ISSN	16807316
起始页码	9309
结束页码	9320
卷号	19 期号:14
英文摘要	Aerosol pH is difficult to measure directly but can be calculated if the chemical composition is known with sufficient accuracy and precision to calculate the aerosol water content and the HC concentration through the equilibrium among acids and their conjugate bases. In practical terms, simultaneous measurements of at least one semivolatile constituent, e.g. NH3 or HNO3, are required to provide a constraint on the calculation of pH. Long-term records of aerosol pH are scarce due to the limited monitoring of NH3 in conjunction with PM2:5. In this study, 10-year (2007-2016) records of pH of PM2:5 at six eastern Canadian sites were calculated using the E-AIM II model with the input of gaseous NH3, gaseous HNO3 and major water-soluble inorganic ions in PM2:5 provided by Canada's National Air Pollution Surveillance (NAPS) Program. Clear seasonal cycles of aerosol pH were found with lower pH (∼ 2) in summer and higher pH (∼ 3) in winter consistently across all six sites, while the day-to-day variations of aerosol pH were higher in winter compared to summer. Tests of the sensitivity of aerosol pH to meteorological parameters demonstrate that the changes in ambient temperature largely drive the seasonal cycle of aerosol pH. The sensitivity of pH to chemical composition shows that pH has different responses to the changes in chemical composition in different seasons. During summertime, aerosol pH was mainly determined by temperature with limited impact from changes in NHx or sulfate concentrations. However, in wintertime, both meteorological parameters and chemical composition contribute to the variations in aerosol pH, resulting in the larger variation during wintertime. This study reveals that the sensitivity of aerosol pH to chemical composition is distinctly different under different meteorological conditions and needs to be carefully examined for any particular region. © 2019 Author(s).
语种	英语
scopus关键词	acidity; aerosol; atmospheric chemistry; chemical composition; monitoring system; particulate matter; Phaeozem; seasonal variation; sensitivity analysis; Canada
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/144269
作者单位	Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, ON M1C 1A4, Canada; Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada
推荐引用方式 GB/T 7714	Tao Y.,Murphy J.G.. The sensitivity of PM2.5 acidity to meteorological parameters and chemical composition changes: 10-year records from six Canadian monitoring sites[J],2019,19(14).
APA	Tao Y.,&Murphy J.G..(2019).The sensitivity of PM2.5 acidity to meteorological parameters and chemical composition changes: 10-year records from six Canadian monitoring sites.Atmospheric Chemistry and Physics,19(14).
MLA	Tao Y.,et al."The sensitivity of PM2.5 acidity to meteorological parameters and chemical composition changes: 10-year records from six Canadian monitoring sites".Atmospheric Chemistry and Physics 19.14(2019).