Spatially Resolved Technique for Source Apportionment in New Zealand (SpaRTANZ)
SpaRTANZ is a collaboration between NIWA and Dr Jane Clougherty (University of Pittsburgh) who pioneered the technique in New York City and Pittsburgh.
An experimental study of air pollution composition, called SpaRTANZ, is based on the deployment of air samplers on lamp posts at several locations in a city or neighbourhood.
Analysis of the samples collected from the air samplers provides information on the contributing emission sources in that area (eg. heating, petrol/diesel vehicles, shipping).
The spatial distribution of samplers, combined with GIS analysis, generates maps of various pollutants and source impacts across a study area.
SpaRTANZ began with two pilot studies – one in Auckland CBD in April 2014 followed by inner Christchurch in May 2014. The Christchurch study trialled separate daytime and night-time sampling due to the expected change in dominant emission sources from transport to heating.
SpaRTANZ has some similarities to a source apportionment technique used by GNS Science to probe sources of air pollution in New Zealand, particularly for Regional Councils. The GNS work uses ion beam analysis and receptor modelling to match the elemental composition of particles to known source profiles. However, SpaRTANZ also measures organic compounds and gases, to differentiate impacts of multiple sources across more locations. The GNS studies have primarily been limited to analysis of filters from fixed Council stations, whereas SpaRTANZ deploys its own portable samplers at multiple sites simultaneously (which can then be moved systematically) to provide multiple measurement points. This provides the ‘spatial resolution’ (and maps) which are the key characteristic feature of the method.