Browsing by Author "Galbally, IE"
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- Item40 years of atmospheric composition observations and research at Cape Grim – an overview(Australian Meteorological & Oceanographic Society, 2016-02-08) Krummel, PB; Keywood, MD; Fraser, PJ; Galbally, IE; Steele, PL; Lawson, S; van der Schoot, MV; Wilson, SR; Williams, AG; Cleland, SIn 2016, the Cape Grim station located at the north-west tip of Tasmania, will celebrate 40 years of continuous operation. Commencing operations in 1976, and in its current facilities since 1981, the Baseline Air Pollution Station at Cape Grim is Australia’s contribution to international efforts for monitoring the global background atmosphere for trends due to human activities and natural variability. It is one of the three premier stations in the Global Atmosphere Watch (GAW) network of the World Meteorological Organization (WMO). Cape Grim observations thereby contribute very significantly to the GAW programme, and research outputs are published in peer-reviewed international journals of the highest quality, are very frequently cited, and feed into the international/global assessments, for example the IPCC. Cape Grim’s essential purpose has not changed since the program’s inception in 1976. National and global concern that human activity is having an impact on the composition of the global (and regional) atmosphere requires that the changes be observed and understood. Initially, this was the main focus, whereas now the data are also used for prediction, to guide development of remedial policies, and to verify the effectiveness of global mitigation actions. The critical, but too often unrecognised role of precise in-situ atmospheric observation programs underpinning our current understanding of atmospheric processes and ability to model future climate, is well summarised in a commentary in Nature, titled “Cinderella science” (Nature 450, p789, 2007). The Cape Grim station is operated and funded by the Aust. Bureau of Meteorology, with the Cape Grim Science Program jointly supervised by CSIRO, the Bureau of Met., Univ. of Wollongong and ANSTO. This presentation will give an overview of the past and present measurement programs at the station, show some of the iconic long-term datasets, and summarise some of the science highlights and impacts from the past 40 years.
- ItemComposition 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, SRVolatile 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
- ItemComprehensive 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, JThe 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.
- ItemThe 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, VThe 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.
- ItemSpeculation on the origin of sub-baseline excursions of CH4 at Cape Grim(NOAA Earth System Research Laboratory, 2016-01-01) Loh, ZM; Krummel, PB; Gregory, RL; Steele, LP; Stavert, AR; Schoot, MVVD; Spencer, DA; Mitrevski, B; Thornton, DP; Galbally, IE; Ward, JZ; Somerville, NT; Chambers, SD; Williams, AGThe Advanced Global Atmospheric Gases Experiment (AGAGE) program has historically measured in situ methane (CH4 ) at Cape Grim via gas chromatography with flame ionization detection (GC-FID) in 40 minutely grab samples. By adding continuous, high precision in situ measurements of CH4 (Picarro cavity ring-down spectroscopy [CRDS]) at both Cape Grim, Tasmania, and Casey, Antarctica, a new feature has become apparent in the Cape Grim CH4 record. During the austral summer (December to February), the Cape Grim CH4 record periodically drops below baseline. For example, in Figure 1, a number of sustained episodes of depressed CH4 concentration can be seen below the baseline selected data shown in red. Notably, these episodes are also seen in the GC-FID record. In this presentation, we examine these sub-baseline excursions of CH4 . In conjunction with meteorology and a variety of other chemical species measured at Cape Grim, including radon, ozone, hydrogen and ethane, we speculate on a number of possible mechanisms that might be responsible for these dips in CH4 mixing ratio.
- ItemSydney 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, JThe 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.
- ItemTowards a universal “baseline” characterisation of air masses for high- and low-altitude observing stations using Radon-222(Taiwan Association for Aerosol Research, 2015-07-30) Chambers, SD; Williams, AG; Conen, F; Griffiths, AD; Reimann, S; Steinbacher, M; Krummel, PB; Steele, LP; van der Schoot, MV; Galbally, IE; Molloy, SB; Barnes, JEWe demonstrate the ability of atmospheric radon concentrations to reliably and unambiguously identify local and remote terrestrial influences on an air mass, and thereby the potential for alteration of trace gas composition by anthropogenic and biogenic processes. Based on high accuracy (lower limit of detection 10–40 mBq m–3), high temporal resolution (hourly) measurements of atmospheric radon concentration we describe, apply and evaluate a simple two-step method for identifying and characterising constituent mole fractions in baseline air. The technique involves selecting a radon-based threshold concentration to identify the “cleanest” (least terrestrially influenced) air masses, and then performing an outlier removal step based on the distribution of constituent mole fractions in the identified clean air masses. The efficacy of this baseline selection technique is tested at three contrasting WMO GAW stations: Cape Grim (a coastal low-altitude site), Mauna Loa (a remote high-altitude island site), and Jungfraujoch (a continental high-altitude site). At Cape Grim and Mauna Loa the two-step method is at least as effective as more complicated methods employed to characterise baseline conditions, some involving up to nine steps. While it is demonstrated that Jungfraujoch air masses rarely meet the baseline criteria of the more remote sites, a selection method based on a variable monthly radon threshold is shown to produce credible “near baseline” characteristics. The seasonal peak-to-peak amplitude of recent monthly baseline CO2 mole fraction deviations from the long-term trend at Cape Grim, Mauna Loa and Jungfraujoch are estimated to be 1.1, 6.0 and 8.1 ppm, respectively. © Taiwan Association for Aerosol Research
- ItemUpdate 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, PThe 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).