Urban Air Quality in a Coastal City: Wollongong during the MUMBA Campaign

Clare Paton-Walsh,Stephen Wilson,Melita Keywood,Dagmar Kubistin,Alan Griffiths,Nicholas Jones,Élise-Andrée Guérette,Jason Ward,Ruhi Humphries,Sarah Lawson,Ian Galbally,David Griffith,Rebecca Buchholz,Doreena Dominick,Scott Chambers,Martin Cope,James Harnwell,Kathryn Emmerson

doi:10.3390/atmos9120500

Abstract

We present findings from the Measurements of Urban, Marine and Biogenic Air (MUMBA) campaign, which took place in the coastal city of Wollongong in New South Wales, Australia. We focus on a few key air quality indicators, along with a comparison to regional scale chemical transport model predictions at a spatial resolution of 1 km by 1 km. We find that the CSIRO chemical transport model provides accurate simulations of ozone concentrations at most times, but underestimates the ozone enhancements that occur during extreme temperature events. The model also meets previously published performance standards for fine particulate matter less than 2.5 microns in diameter (PM2.5), and the larger aerosol fraction (PM10). We explore the observed composition of the atmosphere within this urban air-shed during the MUMBA campaign and discuss the different influences on air quality in the city. Our findings suggest that further improvements to our ability to simulate air quality in this coastal city can be made through more accurate anthropogenic and biogenic emissions inventories and better understanding of the impact of extreme temperatures on air quality. The challenges in modelling air quality within the urban air-shed of Wollongong, including difficulties in accurate simulation of the local meteorology, are likely to be replicated in many other coastal cities in the Southern Hemisphere.

Highlights

There is a growing understanding of the impact of poor air quality on premature deaths worldwide [1], underlining the importance of accurate modelling of air quality in populated areas.Recent decades have seen great advances in our understanding of urban air pollution, through both widespread long-term air quality monitoring in populated regions and targeted intensive measurement campaigns [2]
We present observations of key species associated with air quality measured during the MUMBA campaign: Carbon monoxide (CO), sulphur dioxide (SO2 ), nitric oxide (NO); nitrogen dioxide (NO2 ), ozone (O3 ), and particulate matter less than 2.5 microns in diameter (PM2.5 ) and less than 10 microns in diameter (PM10 )
Despite its reputation as an industrialised city, Wollongong contributed 3.6% or less of the anthropogenic emissions of PM2.5, PM10, NOX, SO2 and VOCs listed in the NPI for New South Wales during 2012/2013 and 5% or less of anthropogenic emissions listed in the NSW EPA inventory for

Summary

Introduction

Recent decades have seen great advances in our understanding of urban air pollution, through both widespread long-term air quality monitoring in populated regions and targeted intensive measurement campaigns [2]. Targeted intensive campaigns, measuring a broad range of gaseous species and aerosol properties, are required to investigate the complexity of secondary organic aerosol formation and its coupling with gas phase photochemistry. Such a comprehensive suite of measurements is generally beyond the scope of long term monitoring programmes. Previous campaigns have often concentrated on characterising a distinct environment, such as the urban air-shed [10]; forested regions dominated by biogenic emissions [17,18] or remote coastal regions that are heavily influenced by marine aerosol [13,19,20]

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Discussion

Conclusion