Fine particle characterisation, source apportionment and long-range dust transport into the Sydney Basin: a long term study between 1998 and 2009

AbstractIon beam analysis techniques have been used to characterise fine particle (PM2.5) pollution in the Sydney Basin between 1 July 1998 and 31 December 2009. Nearly 1 200 filters were obtained and analysed for more than 21 different chemical species from hydrogen to lead. Positive matrix factorisation was then applied to this significant database to determine 7 different source fingerprints and their contributions to the total PM2.5 mass. Most of these sources originated in the Sydney Basin, however there were significant windblown soil sources that originated not just from desert regions in central Australia but also from large agricultural regions around 500 km south west of the Basin. This long range transport of fine dust was tracked using hourly back trajectories for every sampling day during the study period and showed that 33% of extreme dust events were probably originating from agricultural regions and not the central desert regions of Australia as first thought

Characterizing Atmospheric Transport Pathways to Antarctica and the Remote Southern Ocean Using Radon-222

We discuss remote terrestrial influences on boundary layer air over the Southern Ocean and Antarctica, and the mechanisms by which they arise, using atmospheric radon observations as a proxy. Our primary motivation was to enhance the scientific community’s ability to understand and quantify the potential effects of pollution, nutrient or pollen transport from distant land masses to these remote, sparsely instrumented regions. Seasonal radon characteristics are discussed at 6 stations (Macquarie Island, King Sejong, Neumayer, Dumont d’Urville, Jang Bogo and Dome Concordia) using 1–4 years of continuous observations. Context is provided for differences observed between these sites by Southern Ocean radon transects between 45 and 67°S made by the Research Vessel Investigator. Synoptic transport of continental air within the marine boundary layer (MBL) dominated radon seasonal cycles in the mid-Southern Ocean site (Macquarie Island). MBL synoptic transport, tropospheric injection, and Antarctic outflow all contributed to the seasonal cycle at the sub-Antarctic site (King Sejong). Tropospheric subsidence and injection events delivered terrestrially influenced air to the Southern Ocean MBL in the vicinity of the circumpolar trough (or “Polar Front”). Katabatic outflow events from Antarctica were observed to modify trace gas and aerosol characteristics of the MBL 100–200 km off the coast. Radon seasonal cycles at coastal Antarctic sites were dominated by a combination of local radon sources in summer and subsidence of terrestrially influenced tropospheric air, whereas those on the Antarctic Plateau were primarily controlled by tropospheric subsidence. Separate characterization of long-term marine and katabatic flow air masses at Dumont d’Urville revealed monthly mean differences in summer of up to 5 ppbv in ozone and 0.3 ng m-3 in gaseous elemental mercury. These differences were largely attributed to chemical processes on the Antarctic Plateau. A comparison of our observations with some Antarctic radon simulations by global climate models over the past two decades indicated that: (i) some models overestimate synoptic transport to Antarctica in the MBL, (ii) the seasonality of the Antarctic ice sheet needs to be better represented in models, (iii) coastal Antarctic radon sources need to be taken into account, and (iv) the underestimation of radon in subsiding tropospheric air needs to be investigated

Influence of bottom boundary conditions for temperature on the heat distribution within oxidising heaps

Different types of boundary conditions for temperature (Dirichlet, Neumann, mixed and some others) at the base of a heap comprising oxidizable material are numerically examined for their influence on temperature distribution and overall heat content within the heap. It is demonstrated that some global heap characteristics (e.g., the total heat content) essentially depend on boundary conditions and corresponding temperature distributions within the heap, whereas other global characteristics (e.g., the overall oxidation rate) are not affected significantly. Practical recommendations on selection of boundary conditions are presented

Preface to the proceedings

This Special Part of the ANZIAM Journal (Electronic Supplement) contains the refereed papers from the eleventh Biennial Computational Techniques and Applications Conference (CTAC2003) held at ICIAM, Sydney 2003. The editors acknowledges the advice and assistance provided by Jerard Barry with the refereeing process. The CTAC series of conferences is held under the auspices of the Computational Mathematics Group of the Australian and New Zealand Industrial and Applied Mathematics (ANZIAM) division of the Australian Mathematics Society. They provide a forum for scientists, engineers, and mathematicians interested in the development of computational techniques and their application to problems of practical importance. Previous conferences in the CTAC series were held at University of Sydney (1983), University of Melbourne (1985), University of Sydney (1987), Griffith University, Brisbane (1989), University of Adelaide (1991), Australian National University, Canberra (1993), Swinburne University of Technology, Melbourne (1995), University of Adelaide (1997), Australian National University, Canberra (1999), The University of Queensland, Brisbane (2001) CTAC2003 Organising Committee Jerard Barry (Chair) Steve Armfield (Co-Chair, Web Editor) Jagoda Crawford (Proceedings Editor) Acknowledgements We gratefully acknowledge financial sponsorship from the following organisations. Gold sponsors AXISS AUSTRALIA The University of New South Wales CSIRO The University of Technology, Sydney Commonwealth Department of Education Science and Training Silver sponsors The University of Sydney The University of Melbourne Bronze sponsors AMAS APAC Australian Bureau of Statistics AC3 Defence Science and Technology The Warren Centre for Advanced Engineering AMSI Australian Mathematical Science Institute NSW First for innovation Elsevier Congress Lanyards ILOG SIA

The universal imprint of oxygen isotopes can track the origins of seafood

Identifying the source of seafood is critical for combatting seafood fraud, but current tools are predominantly developed and applied on a species-specific basis. This study investigates how multiple marine taxa could be geolocated at global scales by exploiting stable oxygen isotope compositions in carbonate biominerals (δ 18O biomin), where we expect to see universally expressed and predictable spatial variation in δ 18O biomin values across taxa. We constructed global ocean isoscapes of predicted δ 18O biomin values specific to fish (otoliths), cephalopod (statoliths) and shellfish (shells), and a fourth combined “universal” isoscape, and evaluated their capacity to derive δ 18O biomin values among known-origin samples. High correspondence between isoscape-predicted δ 18O biomin values and a compiled database of measured, georeferenced values (3954 datapoints encompassing 68 species) indicated that this δ 18O biomin approach works effectively, particularly in regions with highly resolved projections of seawater δ 18O composition. When compared to taxon-specific isoscapes, the universal isoscape demonstrated similar accuracy, indicating exciting potential for universal provenance applications. We tested the universal framework via a case study, using machine-learning models to identify sample origins amongst regions of divergent (Tropical Asia vs Temperate Australasia) and similar (Temperate Asia vs Temperate Australasia) climates and latitudes. Classification accuracy averaged 75.3% between divergent regions, and 66% between similar regions. When endothermic tuna species were excluded from the analysis, the accuracy between divergent regions increased up to 90% between divergent regions. This study presents the first empirical step towards developing universal chemical markers, which have the potential to support a more inclusive and global approach of validating provenance of seafood. </p

Evaluating the Application of Portable Handheld X-ray Fluorescence (XRF) Scanner for Determining Seafood Provenance: A Case Study on Penaeus monodon

Seafood elemental profiling (SEP) is the quantification of a range of elements in seafood products and may serve in addressing questions of seafood provenance and quality. Traditional methods for analyzing soft tissue present several limitations for the industry-level use of SEP. Portable handheld X-ray fluorescence (pXRF) analysis is a promising alternative to conventional methods; however, its application for biological analysis has not been fully established. Intact giant tiger prawn (Penaeus monodon) abdomens were analyzed with a Vanta M series XRF portable analyzer following a novel soft tissue protocol. Exploratory statistics (principal component analysis, nonmetric multidimensional scaling, and canonical discriminant analysis), as well as random forest models, have been implemented with pXRF profiles, yielding 81% accuracy when assigning the geographical origin of P. monodon. The results of this study highlight that SEP via pXRF is a viable industry-level analysis, and its application will depend on improved instrument calibration to account for fluctuating wetness factors that are influenced by cooking, storage, and other pre- and post-harvest treatments