Particulate Pollution in the Sydney Region: Source Diagnostics and Synoptic Controls

Abstract

Airborne particulate matter (PM 2.5 ) was sampled at Richmond and Liverpool, located in the Sydney Basin, Australia, and ion beam analysis was used to obtain the elemental composition. Using self-organising maps to classify synoptic weather systems, it was found that high PM 2.5 concentrations were associated with high pressure systems located to the east of the sampling sites. The highest median sulfur was associated with weak synoptic conditions and high soil dust days were more often associated with frontal systems.To investigate the effect of local flows in the Sydney Basin, the Weather Research and Forecasting model (WRF) was used to generate meteorological data of 12 km resolution. A comparison was made between back trajectories generated using the higher-resolution WRF data, the 0.5° by 0.5° Climate Forecast System data and the 1° by 1° Global Data Assimilation System data. It was found that for high soil dust days, there were small differences between the different back trajectories. However, under weak synoptic conditions (high sulfur days), the back trajectories generated from higher resolution data showed larger variations over a 24 hr period. This was attributed to the meandering of local winds and seabreezes.Lower altitude back trajectories, generated from low resolution data, passed more often over the power stations located on the western side of the Great Dividing Range (while the sampling sites are on the east). This demonstrates the need for higher resolution meteorological data for generating low altitude back trajectories when the source and receptor are separated by hilly terrain.In estimating the number of high sulfur days for which a power station was crossed, there was up to 20% difference at Liverpool and up to 10% difference at Richmond, between back trajectories starting at different altitudes and generated from meteorological data of three different resolutions.

Visualising the relationships between synoptic circulation type and air quality in Sydney, a subtropical coastal‐basin environment

“…Hot and sunny weather conditions can potentially increase fine particle and precursor emissions (e.g., increased fugitive dust emissions and VOC emissions from biogenic and anthropogenic sources due to high temperatures, and SO 2 emissions due to increased fossil fuel burning in power plants under high energy demand), enhance photochemical activity and the formation of secondary particles (e.g., conversion of SO 2 to secondary sulphate; Eatough et al , ) and consequently lead to elevated particle pollution in some parts of Sydney (Cohen et al , ; Cope et al , ). Furthermore, particles released in regions to the north of Sydney can be transported into Sydney under prevailing northerly winds (Hyde et al , ; Crawford et al , ). For example, under Type 3, the prevailing northerly (synoptic) flows over the west of the basin may have facilitated the transport of PM 2.5 or particle precursor emissions from regions such as the Hunter Valley where PM 10 pollution is relatively higher (Nelson et al , ; NSWEPA, ), further adding to elevated particle pollution over the south‐west of Sydney.…”

“…This article extends Jiang et al (2016) and Crawford et al (2016) by using long-term, multi-site data to further examine how synoptic processes modulate the warm-month daily O 3 , PM 10 and visibility (as 1213 a proxy of PM 2.5 ; Wilson et al, 2002) levels in Sydney. We provide a visual insight into how mesoscale and synoptic meteorological conditions affect local air quality in tandem.…”

“…Recently, Jiang et al (, ) used the self‐organising map (SOM) method to summarise long‐term, multi‐site climate and air quality (O 3 ) data for the region, showing that synoptic systems can modulate the spatial patterns of local air flows and subsequently, the spatial variability in observed O 3 pollution. Further, Crawford et al (), using the same SOM classification, linked synoptic circulation types to PM 2.5 pollution at two monitoring sites in this region. They noted that high PM 2.5 concentrations were associated with high pressure systems located south‐east of Australia, while high soil dust days were more often associated with the passage of frontal systems; however, they did not include analyses of the influence of mesoscale features.…”

Atmospheric aerosols analysis and identification of polluting sources in the industrial city of Arak, Iran

“…Several studies have been carried out on the particulate matter based on the characteristic X‐ray spectroscopy techniques in several industrial areas and cities around the world [8–17] . In this field, the ion beam analysis techniques have also been widely used to investigate the fine particulate matter composition [18–23] . Particularly, the PIXE has noteworthy application in the study of the long‐term atmospheric aerosol composition besides to advantageous features in the elemental composition determination of the aerosol samples [24,25] .…”

Impact of Atmospheric Flow Conditions on Fine Aerosols in Sydney, Australia

“…This data was generated using the Weather Research and Forecasting (WRF) model version 3.5.1 with the ARW dynamical core (Skamarock et al, 2004;Skamarock and Klemp, 2008). The details of the model set up and simulations were given in the supplementary material to Crawford et al (2016b). The domain of the WRF simulation was between longitudes 145.291° and 158.709°, and latitude -38.2885° and -27.5621° and the simulations were generated for all time from January 2007 to December 2009, with a temporal resolution of one hour.…”