Levoglucosan and phenols in Antarctic marine, coastal and plateau aerosols
Graphical abstract
Introduction
Biomass burning encompasses the combustion of living and dead vegetation, and includes wildfires, prescribed burning (deforestation, shifting cultivation, agriculture waste) and domestic bio-fuel combustion (such as in fireplaces, stoves) (Cheng et al., 2013). Humans intentionally and accidentally ignite fires although volcanic activity and lightning also lead to forest fires (Taylor, 2010). Biomass combustion is the largest source of primary fine carbonaceous particles and the second principal source of trace gases in the global atmosphere (Akagi et al., 2011).
Biomass burning aerosols influence the climate system by affecting the Earth's solar balance (IPCC, 2013, Hobbs et al., 1997), acting as cloud condensation nuclei (Novakov and Corrigan, 1996, Vestin et al., 2007) and influencing snow albedo (IPCC, 2013, Flanner et al., 2007, Ramanathan and Carmichael, 2008). However, the transport, evolution and sinks of many biomass burning aerosols are not well understood. Here, we examine two classes of biomass burning tracers (levoglucosan and phenolic compounds) in Antarctic plateau, coastal, and oceanic sites to determine how distance from biomass burning source regions and subsequent transport and aging affects their concentrations and size distribution.
Antarctica is surrounded by ocean, contains little to no biomass burning sources, lacks stable human settlements, and therefore presents a natural laboratory for investigating biomass burning aerosols after long range transport. We examine the specific biomarker levoglucosan (1,6 anhydro-β-D glucopyranose) as it is an unambiguous product of cellulose combustion produced at temperatures of approximately 250 °C (Kuo et al., 2011). Here, we use levoglucosan as a reference biomass burning tracer due to its specificity and high emission factors (Iinuma et al., 2007, Oros et al., 2006, Oros and Simoneit, 2001a, Oros and Simoneit, 2001b). Although levoglucosan can degrade in the atmosphere by reacting with OH (Hennigan et al., 2010, Hoffmann et al., 2010, Kessler et al., 2010), NO3 and SO4− (Hoffmann et al., 2010), the high concentrations injected into smoke plumes suggest that enough remains to allow using levoglucosan as a biomass burning tracer (Hoffmann et al., 2010). In Arctic aerosols levoglucosan was determined both in conditions influenced by (Stohl et al., 2006, Stohl et al., 2007) and not influenced (Fu et al., 2009, von Schneidemesser et al., 2009, Yttri et al., 2014, Zangrando et al., 2013) by wildfires, while in Antarctica studies only observe levoglucosan in marine aerosols (Hu et al., 2013). Ice core (Gambaro et al., 2008, Kawamura et al., 2012, Legrand et al., 2007, Yao et al., 2013) and snow pit (Hegg et al., 2010, Kehrwald et al., 2012) studies demonstrate that levoglucosan can reconstruct past biomass burning over annual to millennial timescales (Zennaro et al., 2014) in polar locations.
While levoglucosan records cellulose burning, this marker alone cannot determine what type of vegetation burned to produce the smoke aerosols. PCs in atmospheric aerosols may indicate the types of burned plants. Methoxy phenols derive from lignin combustion. Lignin is a biopolymer comprised of three different aromatic alcohols; p-coumaryl, coniferyl and sinapyl alcohols where their proportions differ between the major plant classes. The degradation products from oxidation or burning of lignin are classified as coumaryl, vanillyl and syringyl moieties (Simoneit, 2002). Hardwood (angiosperm) lignin (Oros and Simoneit, 2001b) is enriched in sinapyl alcohol precursors so burning these plants principally produces syringyl and vanillyl moieties. In deciduous tree smoke the main PCs produced include homovanillyl alcohol, vanillic acid, vanillin, and syringic acid. Softwoods (gymnosperms) (Oros and Simoneit, 2001a) contain high proportions of coniferyl alcohol with minor components from sinapyl alcohol and burning produces primarily vanillyl moieties. The dominant phenolic biomarkers in conifer smoke include vanillin, homovanillic acid, vanillic acid, and homovanillyl alcohol. In grasses (gramineae) (Oros et al., 2006) p-coumaryl alcohol is the dominant lignin unit not prevalent in softwood and hardwood. Other significant products from burning grasses are acetosyringone, syringic acid, vanillin and vanillic acid. Methoxy phenols degrade in the atmosphere, where 2-methoxyphenol (guaiacol) and its isomers in the gas-phase react with OH hydroxyradicals (Coeur-Tourneur et al., 2010), while phenols react with 3C⁎ (aromatic carbonyl) (Smith et al., 2014) and some methoxy phenols in particulate matter react with O3 (Net et al., 2011), NO3 (Liu et al., 2012), 3C⁎(Yu et al., 2014), OH (Li et al., 2014, Yu et al., 2014), and UV (Li et al., 2014).
Most previous determinations of PCs in aerosols were performed in zones close to residential areas using biomass burning in domestic heating (Bari et al., 2010, Bari et al., 2011, Dutton et al., 2009, Dutton et al., 2010, He et al., 2010, Simpson et al., 2005, Ward et al., 2011) or else in zones heavily impacted from wildfire smoke (Ward et al., 2006). PCs occur in high concentrations near these biomass burning sources, ranging from 10 s to greater than 10,000 pg m− 3 (Bari et al., 2010, Bari et al., 2011, Dutton et al., 2009, Dutton et al., 2010, He et al., 2010, Simpson et al., 2005, Ward et al., 2011). In the Arctic, PCs have considerably lower concentrations with mean values (for particle sizes of 10 μm to < 0.49 μm) of 14 pg m− 3 (Zangrando et al., 2013). Several studies determine PCs in ice and snow collected in Arctic areas (Hegg et al., 2010, Kawamura et al., 2012, McConnell et al., 2007), suggesting their applicability to Antarctic sites.
This work determines levoglucosan and PCs including vanillic acid (VA), isovanillic acid (IVA), homovanillic acid (HA), syringic acid (SyA), vanillin (VAN), syringaldehyde (SyAH), ferulic acid (FA), p-coumaric acid (PA) and coniferyl aldehyde (CAH) in three different Antarctic environments in order to investigate how transport affects the concentrations, evolution and sinks of these compounds in aerosols. We examine the concentrations and particle size distributions of biomass burning tracers in remote aerosols at the Concordia Station (Dome C) on the East Antarctic plateau during 2011–2012, 2012–2013, the coastal Mario Zucchelli Station in 2010–2011, and marine aerosol samples collected during the R/V Italica oceanographic cruise in the Southern Ocean in 2012 (Fig. 1).
Section snippets
Reagents and standard solutions
HPLC/MS-grade methanol (MeOH) and acetonitrile (ACN) were purchased from Romil LTD (Cambridge, U.K.). The ultrapure water (18.2 MΩ cm, 0.01 TOC) was produced by a Purelab Flex (Elga, High Wycombe, U.K.) and formic acid (98%) was obtained by Fluka (Sigma Aldrich, Buchs, Switzerland). Levoglucosan (purity 99%), vanillin (VAN) (≥ 98%), syringic acid (SyA) (≥ 95%), homovanillic acid (HA) (≥ 98%), isovanillic acid (IVA) (97%), p-coumaric acid (PA) (≥ 98%), coniferyl aldehyde (CAH) (98%), were purchased
Levoglucosan and phenolic compounds in total suspended particles over the Southern Ocean
We determined levoglucosan and PCs in aerosol samples collected over the Southern Ocean during the R/V Italica research cruise from January 13 to February 19, 2012 during the trip to and from Mario Zucchelli Station. Sample summaries, and sampling details in Table S2, while Table 1 records atmospheric concentrations of levoglucosan and PCs. Median levoglucosan concentrations were 37.6 pg m− 3, ranging from BDL to 224.1 pg m− 3 (Fig. S2 and Table S6) and the median phenolic compound concentrations for
Conclusions
Here, we determined that levoglucosan can be detected in remote areas, even in sites as distant from biomass burning sources as Dome C, East Antarctica. Our results indicate that the biomass burning tracer levoglucosan reached the inner Antarctic plateau through long-range transport and was present in accumulation-mode aerosols. At the coastal site levoglucosan was substantially present on coarse particles created by hygroscopic growth. During an oceanographic cruise on the Ross Sea when winds
Acknowledgments
This work was financially supported by the Italian Programma Nazionale di Ricerche in Antartide (PNRA) through the project 2009/A2.11.
The research was also supported by funding from the National Research Council of Italy (CNR) and from ERC Advanced Grant n° 267696, contribution n° 17.
The authors gratefully acknowledge the NOAA Air Resources Laboratory (ARL) for providing the HYSPLIT transport and dispersion model and/or READY website (http://www.ready.noaa.gov) used in this publication.
We
References (99)
- et al.
Wood smoke as a source of particle-phase organic compounds in residential areas
Atmos. Environ.
(2009) - et al.
Temporal variation and impact of wood smoke pollution on a residential area in southern Germany
Atmos. Environ.
(2010) - et al.
Molecular indicators of the sources and transformations of dissolved organic matter in the Mississippi river plume
Org. Geochem.
(2001) - et al.
PM(2.5) characterization for time series studies: organic molecular marker speciation methods and observations from daily measurements in denver
Atmos. Environ.
(2009) - et al.
Temporal patterns in daily measurements of inorganic and organic speciated PM(2.5) in Denver
Atmos. Environ.
(2010) Dissolved vanillin as tracer for estuarine lignin conversion
Estuar. Coast. Shelf Sci.
(1996)- et al.
What happens to terrestrial organic matter in the ocean?
Org. Geochem.
(1997) - et al.
Ice core records of biomass burning tracers (levoglucosan and dehydroabietic, vanillic and p-hydroxybenzoic acids) and total organic carbon for past 300 years in the Kamchatka Peninsula, northeast Asia
Geochim. Cosmochim. Acta
(2012) - et al.
Differential presence of anthropogenic compounds dissolved in the marine waters of Puget sound, WA and Barkley Sound, BC
Mar. Pollut. Bull.
(2011) - et al.
Diurnal variation in the water-soluble inorganic ions, organic carbon and isotopic compositions of total carbon and nitrogen in biomass burning aerosols from the LBA-SMOCC campaign in Rondonia, Brazil
J. Aerosol Sci.
(2010)