Browsing by Author "Selleck, PW"

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    Composition of clean marine air and biogenic influences on VOCs during the MUMBA campaign
    (MDPI AG, 2019-07-10) Guérette, ÉA; Paton-Walsh, C; Galbally, IE; Molloy, SB; Lawson, S; Kubistin, D; Buchholz, R; Griffith, DWT; Langenfelds, RL; Krummel, PB; Loh, Z; Chambers, SD; Griffiths, AD; Keywood, MD; Selleck, PW; Dorminick, D; Humphries, R; Wilson, SR
    Volatile organic compounds (VOCs) are important precursors to the formation of ozone and fine particulate matter, the two pollutants of most concern in Sydney, Australia. Despite this importance, there are very few published measurements of ambient VOC concentrations in Australia. In this paper, we present mole fractions of several important VOCs measured during the campaign known as MUMBA (Measurements of Urban, Marine and Biogenic Air) in the Australian city of Wollongong (34°S). We particularly focus on measurements made during periods when clean marine air impacted the measurement site and on VOCs of biogenic origin. Typical unpolluted marine air mole fractions during austral summer 2012-2013 at latitude 34°S were established for CO2 (391.0 ± 0.6 ppm), CH4 (1760.1 ± 0.4 ppb), N2O (325.04 ± 0.08 ppb), CO (52.4 ± 1.7 ppb), O3 (20.5 ± 1.1 ppb), acetaldehyde (190 ± 40 ppt), acetone (260 ± 30 ppt), dimethyl sulphide (50 ± 10 ppt), benzene (20 ± 10 ppt), toluene (30 ± 20 ppt), C8H10 aromatics (23 ± 6 ppt) and C9H12 aromatics (36 ± 7 ppt). The MUMBA site was frequently influenced by VOCs of biogenic origin from a nearby strip of forested parkland to the east due to the dominant north-easterly afternoon sea breeze. VOCs from the more distant densely forested escarpment to the west also impacted the site, especially during two days of extreme heat and strong westerly winds. The relative amounts of different biogenic VOCs observed for these two biomes differed, with much larger increases of isoprene than of monoterpenes or methanol during the hot westerly winds from the escarpment than with cooler winds from the east. However, whether this was due to different vegetation types or was solely the result of the extreme temperatures is not entirely clear. We conclude that the clean marine air and biogenic signatures measured during the MUMBA campaign provide useful information about the typical abundance of several key VOCs and can be used to constrain chemical transport model simulations of the atmosphere in this poorly sampled region of the world. © 2019 The Authors
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    Comprehensive aerosol and gas data set from the Sydney Particle Study
    (Copernicus Publications, 2019-12-02) Keywood, MD; Selleck, PW; Reisen, F; Cohen, DD; Chambers, SD; Cheng, M; Cope, M; Crumeyrolle, S; Dunne, E; Emmerson, K; Fedele, R; Galbally, IE; Gillett, R; Griffiths, AD; Guerette, EA; Harnwell, J; Humphries, R; Lawson, S; Miljevic, B; Molloy, SB; Powell, J; Simmons, J; Ristovksi, Z; Ward, J
    The Sydney Particle Study involved the comprehensive measurement of meteorology, particles and gases at a location in western Sydney during February–March 2011 and April–May 2012. The aim of this study was to increase scientific understanding of particle formation and transformations in the Sydney airshed. In this paper we describe the methods used to collect and analyse particle and gaseous samples, as well as the methods employed for the continuous measurement of particle concentrations, particle microphysical properties, and gaseous concentrations. This paper also provides a description of the data collected and is a metadata record for the data sets published in Keywood et al. (2016a, https://doi.org/10.4225/08/57903B83D6A5D) and Keywood et al. (2016b, https://doi.org/10.4225/08/5791B5528BD63). © Author(s) 2019. This work is distributed under the Creative Commons Attribution 4.0 Licence.
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    Lower Hunter particle characterisation study - chemical speciation and positive matrix factorisation factor concentration data set
    (Office of Environment and Heritage and Environment Protection Authority, 2016-04-01) Hibberd, MF; Keywood, MD; Selleck, PW; Cohen, DD; Stelcer, E; Scrogie, Y; Chang, L
    The Lower Hunter Particle Characterisation Study was commissioned by the NSW Environment Protection Authority in 2013 to investigate the composition and major sources of particle pollution in the Lower Hunter. The study was conducted by scientists from the former Office of Environment and Heritage (OEH), CSIRO and the Australian Nuclear Science and Technology Organisation (ANSTO), with oversight from the NSW Ministry of Health, and completed in 2016. Focusing on very small particles, invisible to the human eye, which can be inhaled and can pass through the throat and nose and into the lungs, the study aimed to determine the composition and major sources of fine particles (PM2.5) and coarse particles (PM2.5-10). Fine particles were monitored at four sites, including two sites representative of regional population exposures (Newcastle, Beresfield) and two sites near the Port of Newcastle (Mayfield and Stockton). Coarse particles were monitored at Mayfield and Stockton, the two sites near the Port of Newcastle.
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    Lower Hunter particle characterisation study appendices to the final report to the NSW Environment Protection Authority
    (Office of Environment and Heritage and Environment Protection Authority, 2016-04-01) Hibberd, MF; Keywood, MD; Selleck, PW; Cohen, DD; Stecler, E; Scorgie, Y; Chang, L
    The Lower Hunter Particle Characterisation Study was commissioned by the NSW Environment Protection Authority in 2013 to investigate the composition and major sources of particle pollution in the Lower Hunter. The study was conducted by scientists from the former Office of Environment and Heritage (OEH), CSIRO and the Australian Nuclear Science and Technology Organisation (ANSTO), with oversight from the NSW Ministry of Health, and completed in 2016. Focusing on very small particles, invisible to the human eye, which can be inhaled and can pass through the throat and nose and into the lungs, the study aimed to determine the composition and major sources of fine particles (PM2.5) and coarse particles (PM2.5-10). Fine particles were monitored at four sites, including two sites representative of regional population exposures (Newcastle, Beresfield) and two sites near the Port of Newcastle (Mayfield and Stockton). Coarse particles were monitored at Mayfield and Stockton, the two sites near the Port of Newcastle.
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    Lower Hunter particle characterisation study Final Report to the NSW Environment Protection Authority
    (Office of Environment and Heritage and Environment Protection Authority, 2016-04-01) Hibberd, MF; Keywood, MD; Selleck, PW; Cohen, DD; Stelcer, E; Scorgie, Y; Chang, L
    The Lower Hunter Particle Characterisation Study (LHPCS) provides details about the composition and major sources of PM2.5 (fine airborne particles)and PM2.5-10(coarse airborne particles). Measurements were made for one year from March 2014 to February 2015 at two air quality monitoring stations representative of regional population exposures (Newcastle and Beresfield) and two stations near the Port of Newcastle (Mayfield and Stockton). Annual average PM2.5 concentrations were very similar at Newcastle, Mayfield and Beresfield (6.4–6.7 μg m-3) but about 40% higher at Stockton (9.1 μg m-3). The higher levels at Stockton were mainly due to both more sea salt and to the primary ammonium nitrate, which was only detected at Stockton. The ammonium nitrate, which contributed on average 19% of the PM2.5 mass (and ~40% in winter), was identified as very likely to be due to primary emissions from Orica’s ammonium nitrate manufacturing facility on Kooragang Island. Other than the ammonium nitrate, PM2.5 composition and sources were found to be fairly similar across the four sites. Key results on the sources and their contributions are: fresh sea salt particles: 24% at Newcastle, decreasing to 13% at Beresfield; pollutant-aged sea salt: ~23% at all sites; this is sea salt reacted with industrial, commercial, road and non-road transport emissions from local and regional sources; wood smoke: 15% at Beresfield, decreasing to 6% at Stockton; secondary ammonium sulfate: ~10% at all sites; soil dust: ~10% at all sites; vehicles: ~10% at three sites, but only 5% at Stockton; industry factors: ~12% at three sites but 24% at Stockton; mixed shipping/industry: ~3% at all sites; nitrate: 19% ammonium nitrate at Stockton and secondary nitrate at other sites (6-11%). On an annual average basis, there is an approximately 50:50 split between primary and secondary particles at three sites (Newcastle, Beresfield and Mayfield) and a 65:35 split at Stockton because of the significant contribution from the primary ammonium nitrate. PM2.5-10 composition and sources were only determined at the stations near the Port of Newcastle. The 2½ times higher annual average PM2.5-10 concentration at Stockton (21.5 μg m-3) than at Mayfield (8.3 μg m-3) was found to be mainly due to a much higher contribution by fresh sea salt particles at Stockton. The PM2.5-10 factors and their contributions were identified as:  fresh sea salt: 13.6 μg m-3 at Stockton, 3.3 μg m-3 at Mayfield  industry plus pollutant-aged sea salt: 2.4 μg m-3 at both sites  light-absorbing carbon: 2.2 μg m-3 at Stockton, 0.9 μg m-3 at Mayfield  soil: 2.3 μg m-3 at Stockton, 1.2 μg m-3 at Mayfield  bioaerosol: 1.1 μg m-3 at Stockton, 0.5 μg m-3 at Mayfield. Most PM2.5-10 particles are primary particles or physical combinations of primary emissions, but there is evidence of chemical reactions in the pollutant-aged sea salt factor. Coal particles could contribute up to 10% of PM2.5-10 particles. Further investigations are needed to clarify the contribution of coal.
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    Marine productivity and synoptic meteorology drive summer-time variability in Southern Ocean aerosols
    (Copernicus Publications, 2020-07-10) Alroe, J; Cravigan, LT; Miljevic, B; Johnson, GR; Selleck, PW; Humphries, RS; Keywood, MD; Chambers, SD; Williams, AG; Ristovski, ZD
    Cloud–radiation interactions over the Southern Ocean are not well constrained in climate models, in part due to uncertainties in the sources, concentrations, and cloud-forming potential of aerosol in this region. To date, most studies in this region have reported measurements from fixed terrestrial stations or a limited set of instrumentation and often present findings as broad seasonal or latitudinal trends. Here, we present an extensive set of aerosol and meteorological observations obtained during an austral summer cruise across the full width of the Southern Ocean south of Australia. Three episodes of continental-influenced air masses were identified, including an apparent transition between the Ferrel atmospheric cell and the polar cell at approximately 64∘ S, and accompanied by the highest median cloud condensation nuclei (CCN) concentrations, at 252 cm−3. During the other two episodes, synoptic-scale weather patterns diverted air masses across distances greater than 1000 km from the Australian and Antarctic coastlines, respectively, indicating that a large proportion of the Southern Ocean may be periodically influenced by continental air masses. In all three cases, a highly cloud-active accumulation mode dominated the size distribution, with up to 93 % of the total number concentration activating as CCN. Frequent cyclonic weather conditions were observed at high latitudes and the associated strong wind speeds led to predictions of high concentrations of sea spray aerosol. However, these modelled concentrations were not achieved due to increased aerosol scavenging rates from precipitation and convective transport into the free troposphere, which decoupled the air mass from the sea spray flux at the ocean surface. CCN concentrations were more strongly impacted by high concentrations of large-diameter Aitken mode aerosol in air masses which passed over regions of elevated marine biological productivity, potentially contributing up to 56 % of the cloud condensation nuclei concentration. Weather systems were vital for aerosol growth in biologically influenced air masses and in their absence ultrafine aerosol diameters were less than 30 nm. These results demonstrate that air mass meteorological history must be considered when modelling sea spray concentrations and highlight the potential importance of sub-grid-scale variability when modelling atmospheric conditions in the remote Southern Ocean. © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License.
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    The MUMBA campaign: measurements of urban, marine and biogenic air
    (Copernicus Publications, 2017-06-06) Paton-Walsh, C; Guérette, ÉA; Kubistin, D; Humphries, R; Wilson, SR; Dominick, D; Galbally, IE; Buchholz, R; Bhujel, M; Chambers, SD; Cheng, M; Cope, M; Davy, P; Emmerson, K; Griffith, DWT; Griffiths, AD; Keywood, MD; Lawson, S; Molloy, SB; Rea, G; Selleck, PW; Shi, X; Simmons, J; Velazco, V
    The Measurements of Urban, Marine and Biogenic Air (MUMBA) campaign took place in Wollongong, New South Wales (a small coastal city approximately 80 km south of Sydney, Australia) from 21 December 2012 to 15 February 2013. Like many Australian cities, Wollongong is surrounded by dense eucalyptus forest, so the urban airshed is heavily influenced by biogenic emissions. Instruments were deployed during MUMBA to measure the gaseous and aerosol composition of the atmosphere with the aim of providing a detailed characterisation of the complex environment of the ocean–forest–urban interface that could be used to test the skill of atmospheric models. The gases measured included ozone, oxides of nitrogen, carbon monoxide, carbon dioxide, methane and many of the most abundant volatile organic compounds. The aerosol characterisation included total particle counts above 3 nm, total cloud condensation nuclei counts, mass concentration, number concentration size distribution, aerosol chemical analyses and elemental analysis. The campaign captured varied meteorological conditions, including two extreme heat events, providing a potentially valuable test for models of future air quality in a warmer climate. There was also an episode when the site sampled clean marine air for many hours, providing a useful additional measure of the background concentrations of these trace gases within this poorly sampled region of the globe. In this paper we describe the campaign, the meteorology and the resulting observations of atmospheric composition in general terms in order to equip the reader with a sufficient understanding of the Wollongong regional influences to use the MUMBA datasets as a case study for testing a chemical transport model. © Author(s) 2017.
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    Sources of particulate matter in the Hunter Valley, New South Wales, Australia
    (Multidisciplinary Digital Publishing Institute (MDPI), 2019-12-18) Keywood, MD; Hibberd, MF; Selleck, PW; Desservattaz, M; Cohen, DD; Stelcer, E; Atanacio, AJ; Scorgie, Y; Chang, L
    Exposure to particulate matter results in adverse health outcomes, especially in sensitive members of the community. Many communities that co-exist with industry are concerned about the perceived impact of emissions from that industry on their health. Such concerns have resulted in two studies in the Hunter Valley of New South Wales, Australia. The chemical composition of samples of particulate matter, collected over two 12-month sampling periods (2012 and 2014–2015) at six sites in the Hunter Valley and across two size fractions (PM2.5 and PM2.5–10) were input to a receptor model to determine the source of particulate matter influencing particle composition at the sites. Fourteen factors were found to contribute to particle mass. Of these, three source profiles common to all sites, size fractions, and sampling periods were sea salt, industry-aged sea salt and soil. Four source profiles were common across all sites for PM2.5 including secondary sulphate, secondary nitrate, mixed industry/vehicles, and woodsmoke. One source profile (other biomass smoke) was only identified in PM2.5 at Singleton and Muswellbrook, two source profiles (mixed industry/shipping and vehicles) were only identified in PM2.5 at Newcastle, Beresfield, Mayfield, and Stockton, and one source (primary nitrate) was only identified at Stockton in PM2.5. Three sources (bioaerosol, light absorbing particles (coal dust), and industry) were only identified in the PM2.5–10 size fraction at Mayfield and Stockton. The contribution of the soil factor to PM2.5 mass was consistent across the sites, while the fresh sea salt factor decreased with distance from the coast from 23% at Stockton to 3% at Muswellbrook, and smoke increased with distance from the coast. Primary industry was greatest at Stockton (due to the influence of ammonium nitrate emitted from a prilling tower) and lowest inland at Muswellbrook. In general, primary emissions across the sites accounted for 30% of the industry sources. The largest contribution to PM2.5 was from secondary sources at all sites except at Muswellbrook, where woodsmoke and industry sources each made an equal contribution of 40%. In general, secondary reactions accounted for approximately 70% of the industry source, although at Stockton, with the presence of the prilling tower, this split was 50% primary and 50% secondary and at Muswellbrook, the split was 20% primary and 80% secondary. These findings add to the evidence base required to inform policies and programs that will improve air quality in the Hunter Valley. © 2019 by the Authors
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    Sydney particle study- stage-II
    (CSIRO Marine and Atmospheric Research, 2014-06) Cope, M; Keywood, MD; Emmerson, K; Galbally, IE; Boast, K; Chambers, SD; Cheng, M; Crumeyrolle, S; Dunne, E; Fedele, R; Gillett, R; Griffiths, AD; Harnwell, J; Katzey, J; Hess, D; Lawson, S; Milijevic, B; Molloy, SB; Powell, J; Reisen, F; Ristovski, Z; Selleck, PW; Ward, J; Chuanfu, C; Zeng, J
    The relationship between particle mass (as PM10 and PM2.5) and health outcomes such as decreased lung function, increased respiratory symptoms, increased chronic obstructive pulmonary disease, increased cardiovascular and cardiopulmonary disease, and increased mortality is now well established. This is well recognised by policy makers in Australia where the Council of Australian Governments has agreed that the initial focus of a new National Plan for Clean Air should be on particles, with the first stage of development being 1/ a health risk assessment; 2/ construction of an exposure reduction framework; 3/ development of emission reduction options and 4/ the undertaking of a cost benefit analysis. As such a quantitative understanding of the sources and sinks of particles within the target airsheds is an essential requirement for achieving the goals of the National Plan for Clean Air. The NSW Office of the Environment and Heritage (OEH) has been pro-active in undertaking, in collaboration with CSIRO, ANSTO and QUT, the subject of this report- the Sydney Particle Study- comprising two field studies (conducted in February 2011 and April, May 2012), and a program of particle model development and application. During the field studies, observations of particles, particle precursor gases and other relevant environmental data were carried out at the Westmead Air Quality Station within the Sydney basin. The modelling task has seen the coupling of a three-dimensional gas-aerosol chemical transport model with the OEH air emissions inventory and the simulation of key particle processes identified by the field campaigns. The study will culminate with the provision of the data, modelling tools and associated training to the OEH air quality modellers, who will then be well placed to contribute aerosol modelling capability to the science and policy development required for the National Plan for Clean Air.
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    Sydney particle study: overview and motivations
    (The Centre for Australian Weather and Climate Research, 2011-11-15) Keywood, MD; Gallaby, I; Cope, M; Boast, K; Chambers, SD; Cheng, M; Dunne, E; Fedele, R; Gillett, R; Griffiths, AD; Lawson, S; Miljevic, B; Molloy, SB; Powell, J; Reisen, F; Ristovski, Z; Selleck, PW; Ward, J
    Studies of health impacts from atmospheric pollutants suggest that particles are currently one of the most significant pollutants with respect to human mortality and morbidity. However, reduction in particle concentrations through source regulation is challenging due to the large number particle sources (both natural and anthropogenic) present in an airshed, and the wide range of particle sizes and chemical species emitted. Additionally, secondary particles can also make a significant contribution to total particle exposure, particularly in the fine size fraction which is considered to have the largest impact on health. Being generated through photochemical processes (similar to ozone), a reduction in the concentration of secondary particles requires that source regulators also consider the relevant gas-phase precursors to these particles. Climate change projections for NSW suggest significant increases in the frequency of drought, increases in the frequency of hot days and increases in the frequency of high fire risk weather. This has important ramifications for air pollution and health, with atmospheric particle smog severity linked to the frequency of hot, sunny days, and with the highest particle pollution concentrations linked to the presence of bushfire plumes in the Sydney airshed. Particles and ozone are also coupled, with enhanced ozone concentrations often observed on bushfire days and with 50% or greater of fine particle mass potentially of photochemical origin. The development of a long term control strategy for particles in Sydney can be informed through the use of comprehensive three-dimensional simulations of the atmosphere, sources and multi-phase phase chemistry. However the development of such modelling capability requires a good understanding of the contribution made by local and remote particles sources to the total particle exposure within the region. Such understanding requires detailed and high quality data sets. We present here an overview of the Sydney Particle Study, a combined modelling and observation project which included an intensive field campaign of aerosol and aerosol precursor measurements carried out in Sydney during February 2011. We focus our discussion on the field campaign which combined sophisticated measurement techniques to produce a high quality data set of atmospheric composition observations. The campaign was a collaboration 43between CSIRO Marine and Atmospheric Research, NSW Office of Environment and Heritage, Queensland University of Technology and ANSTO. Data collected included criteria pollutant concentrations, aerosol microphysical properties, aerosol chemical composition (as a function of size, integrated over 4 hours and in real time), concentration of volatile organic compounds (integrated over 4 hours and in real time) and radon concentrations. Continuous aerosol size distributions indicated the occurrence of secondary aerosol formation occurring in the afternoons on approximately 50% of the days sampled. Data analysis continues in order to understand the processes driving this secondary formation. © 2011 CSIRO and the Bureau of Meteorology.
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    Update on the MUMBA campaign: measurements of urban, marine and biogenic air
    (Atmospheric Composition & Chemistry Observations & Modelling Conference, 2014-09-22) Paton-Walsh, C; Guérette, ÉA; Rea, G; Kubistin, D; Humphries, R; Wilson, SR; Griffith, DWT; Buchholz, R; Velazco, V; Shi, X; Galbally, IE; Keywood, MD; Lawson, S; Selleck, PW; Cheng, M; Molloy, SB; Bhujel, M; Griffiths, AD; Chambers, SD; Davy, P
    The Measurements of Urban, Marine and Biogenic Air (MUMBA) campaign took place in Wollongong, New South Wales (a small coastal city approximately 80 km south of Sydney, Australia), from 21st December 2012 to 15th February 2013. Like many Australian cities, Wollongong is surrounded by dense eucalyptus forest and so the urban air-shed is heavily influenced by biogenic emissions. Instruments were deployed during MUMBA to measure the gaseous and aerosol composition of the atmosphere with the aim of providing a detailed characterisation of the complex environment of the ocean/forest/urban interface that could be used to test the skill of atmospheric models. Gases measured included ozone, oxides of nitrogen, carbon monoxide, carbon dioxide, methane and many of the most abundant volatile organic compounds. Aerosol characterisation included total particle counts above 3 nm, total cloud condensation nuclei counts; mass concentration, number concentration size distribution, aerosol chemical analyses and elemental analysis. The campaign captured varied meteorological conditions, including two extreme heat events, providing a potentially valuable test for models of future air quality in a warmer climate. There was also an episode when the site sampled clean marine air for many hours, providing a useful additional measure of background concentrations of these trace gases within this poorly sampled region of the globe. In this paper we describe the campaign, the meteorology and the resulting observations of atmospheric composition in general terms, in order to equip the reader with sufficient understanding of the Wollongong regional influences to use the MUMBA datasets as a case study for testing a chemical transport model. The data is available from PANGAEA (see https://doi.pangaea.de/10.1594/PANGAEA.871982).
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    Upper Hunter Valley particle characterization study: final report
    (CSIRO Publishing, 2013-09-17) Hibberd, MF; Selleck, PW; Keywood, MD; Cohen, DD; Stelcer, E; Atanacio, AJ
    This study provides an analysis of the composition of PM2.5 (particulate matter with a diameter of less than 2.5 micrometres) in the two main population centres in the Upper Hunter, namely Muswellbrook and Singleton, during 012.The finer PM2.5 particles have been studied because they are of greatest concern owing to their impact on health. Samples were collected for 24 hours every third day and analysed for the components of PM2.5, specifically twenty elements, fourteen soluble ions, two anhydrous sugars (levoglucosan and mannosan) that are found in woodsmoke, organic carbon (OC), and black carbon (BC), as well as gravimetric mass. The chemical composition of all the samples from each site was analysed using a mathematical technique called Positive Matrix Factorisation (PMF), which is widely used in air pollution source apportionment studies. This identified eight factors (also called ‘fingerprints’) which represent the mix of components that tend to vary together in time. Further analysis, using information about known sources and knowledge of atmospheric chemistry as well as wind sector and seasonal analysis, was undertaken to identify the most likely source of emissions for each factor and hence the contribution that each source makes to the measured PM2.5 concentrations. © 2013 CSIRO