Ubiquity and dominance of oxygenated species in organic aerosols in anthropogenically‐influenced Northern Hemisphere midlatitudes

Abstract

Organic aerosol (OA) data acquired by the Aerosol Mass Spectrometer (AMS) in 37 field campaigns were deconvolved into hydrocarbon‐like OA (HOA) and several types of oxygenated OA (OOA) components. HOA has been linked to primary combustion emissions (mainly from fossil fuel) and other primary sources such as meat cooking. OOA is ubiquitous in various atmospheric environments, on average accounting for 64%, 83% and 95% of the total OA in urban, urban downwind, and rural/remote sites, respectively. A case study analysis of a rural site shows that the OOA concentration is much greater than the advected HOA, indicating that HOA oxidation is not an important source of OOA, and that OOA increases are mainly due to SOA. Most global models lack an explicit representation of SOA which may lead to significant biases in the magnitude, spatial and temporal distributions of OA, and in aerosol hygroscopic properties.

Physical and chemical characterization of ambient aerosol by HR‐ToF‐AMS at a suburban site in Hong Kong during springtime 2011

“…During the campaign, total nonrefractory PM 1 (NR-PM 1 ) as measured by the AMS ranged from 0.8 to 72.4 μg/m 3 with an average of 14.5 ± 9.7 μg/m 3 , which is within the upper range of measured concentrations in various other urban environments in the U.S. and Europe [Zhang et al, 2007b] but is significantly lower than what has been observed with AMS in other Chinese cities, e.g., Beijing, Shenzhen, and Kaiping [He et al, 2011;Huang et al, 2010Huang et al, , 2011b. On average, sulfate and organics combined amounted to 79.2% of nonrefractory fine particle mass (Figure 2a) with average concentrations of 7.9 ± 4.8 and 4.4 ± 3.6 μg/m 3 respectively.…”

“…The persistence of notable amounts of SV-OOA and LV-OOA throughout a period of clean easterly air mass (from 5 September to 5 October) points out that considerable portions of the oxygenated organic aerosol are of local or nearregional origin. Despite its location in a suburban area, the HKUST supersite displays compositional features of downwind urban aerosol [Zhang et al, 2007b] with HOA accounting for a quarter of total organic aerosol on average (Figure 7b).…”

A simplified description of the evolution of organic aerosol composition in the atmosphere

“…[2] Organic aerosol (OA) makes up an important, sometimes dominant, fraction of submicron particulate matter in the atmosphere [Zhang et al, 2007]. However, models are generally unsuccessful in reproducing the observed magnitudes and variability of these particles [Capes et al, 2009;de Gouw et al, 2005;Heald et al, 2005Heald et al, , 2006Johnson et al, 2006;Kleinman et al, 2008;Volkamer et al, 2006].…”

Formation of highly oxygenated organic aerosol in the atmosphere: Insights from the Finokalia Aerosol Measurement Experiments

“…However, aerosol mass spectrometry and factor analysis enable differentiation among several types of OA, mostly distinguished by their oxygen content and thermal volatility [Jimenez et al, 2009]. The resulting OA components include hydrocarbon-like OA (HOA), biomass burning OA (BBOA), and oxygenated OA (OOA), a more oxidized component which dominates the total OA mass in most locations [Zhang et al, 2007]. OOA can frequently be further separated into highly oxygenated OA, now referred to as low-volatility OOA (LV-OOA) and less oxygenated OA, referred to as semi-volatile OOA (SV-OOA) [Jimenez et al, 2009;Ng et al, 2010].…”