Browsing by Author "Reisen, F"

Now showing 1 - 4 of 4
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    Investigation of OC and EC fractions of aerosol samples in Sydney area by radiocarbon analysis
    (Australian Nuclear Science and Technology Organisation, 2021-11-17) Yang, B; Keywood, MD; Reisen, F; Smith, AM; Levchenko, VA
    Secondary Organic Aerosols (SOA) can be a major component of atmospheric PM.2.5 pollution, emitted from natural and anthropogenic sources. SOA is formed by the oxidation of volatile organic compounds (VOC) which have biogenic and anthropogenic sources. Measurement of the radiocarbon activity of SOA allows to discriminate between these sources, as biogenic sources have a near-modern activity and anthropogenic sources are generally depleted in ¹⁴ C. As part of the Sydney Particle Study [1,2], aerosol samples were collected on quartz filters using a high volume sampler fitted with a PM2.5 size selective inlet during the summer months of 2011 and autumn months of 2012. In order to estimate the apportionment of the SOA sources, we measured the radiocarbon content of organic carbon (OC) and elemental carbon (EC) fractions, using the novel method described below. We combusted strips (90 × 35 mm) of the quartz filters strip inside a quartz tube filled with high purity oxygen at ~300 mbar at 375°C to collect the OC fraction and then at 780°C to collect the EC fraction. CO₂ gas produced during each combustion was collected in a cold trap at -170°C, volumetrically measured and transferred into a Micro Conventional Furnaces (MCF) [3] for graphitisation. This method was shown to be reproducible for EC and OC filter densities from the same filter. We processed 25 air filters in this way to produce 50 samples for Accelerator Mass Spectroscopy (AMS) measurement with an average of 58 μg carbon (range 10 μg to 220 μg). Our densities compared well with OC and EC densities obtained using a standard thermal desorption method at CSIRO [2]. We combined the measured radiocarbon activity with sophisticated chemical transport modelling, using the EC tracer method [4] to determine SOA. Levoglucosan was used as a tracer to allow for biomass burning events. Our results suggested that i) biogenic SOA comprised around 50% of the SOA in summer and autumn, ii) higher radiocarbon activities for OC are associated with higher SOA concentrations, supporting the model theory [1] that that biogenic VOCs are an important contributor to SOA in the Sydney airshed, iii) the formation of SOA involves both anthropogenic and biogenic VOC, iv) the lowest EC and OC radiocarbon activities were for summer mornings, indicating high fossil fuel carbon (i.e. vehicle emissions). Afternoons in summer and autumn displayed the highest ratios, indicating low fossil fuel carbon. © The Authors
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    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.