Spatial distribution characteristics of some air pollutants in Sydney

Spatial distribution characteristics may be used to help in siting of air m onitoring stations. This technique is also helpful in predicting variations in the concentrations of air pollutants due to changes in meteorology. This paper discusses the spatial distribution patterns at a number of monit oring sites in Sydney. The pollutants modelled are ozone, nitrogen oxides a nd particles as determined by nephelometry. Concentrations, as monthly aver ages, covering a summer and winter period, are used. Spatial cross-correlat ion of time series between sites is also investigated. The correlation anal ysis shows that for most pollutants, the effect is only significant within 30 km around the site. The daily variations in correlation between sites, caused by changing meteo rological conditions, can be minimised by deriving the correlation coeffici ent for each hour in a particular year. This allows the correlation pattern at each hour to be seen and the average effect of meteorology can be revea led by the changing pattern over a 24 h period. This approach is used for e ach hour over 1993 and 1994, based on the correlation matrices of ozone, ni trogen dioxides and nephelometry. Crown Copyright (C) 2000 Published by Els evier Science B.V. on behalf of IMACS. All rights reserved.