NIWA trials new generation air quality sensors
A new method of testing air quality in towns around New Zealand has been developed by NIWA scientists that could revolutionise the way communities can measure and control pollution.
For the past 12 months NIWA has been testing a prototype low-cost dust sensor package called ODIN, or Outdoor Dust Information Node.
The first field trial is about to get under way in Rangiora, North Canterbury.
Air quality scientist Dr Ian Longley says this new generation of low-cost sensors has the potential for communities to observe, understand and control their local air quality in a much more direct way than previously possible.
“Many New Zealand towns have a single air quality monitoring station, run by their regional or district council, whereas others have none. But what if reducing costs and size meant that every neighbourhood could have one?
“We suspect this would be a game-changer in being able to identify problems and their causes and enable communities to work more constructively with councils on devising solutions,” Dr Longley said.
In Rangiora, the NIWA the team will collect information that will help them understand how much woodsmoke is in the air in different parts of the town.
Temperature sensors will be installed in a small number of homes to detect when the woodburner is being used. Other locals will be recruited to fill in an online survey of woodburning in their home. This data will then be combined to estimate how the number of homes burning wood, and the scale of emissions, varies through the night and through the winter.
The study marks the first field trial of the ODINs and will test their robustness and their data quality. The data collected will also be used to observe whether different parts of the town have different air quality, and will also be used by the researchers to further understand how air quality varies from day to day and from place to place, not just in Rangiora but in other similar towns across the country.
Rangiora has been selected as the ideal starting place for several reasons: it has an established problem of high levels of airborne particles on winter nights that often breach air quality standards. Also the town is an ideal size for the trial and has an existing air quality monitoring station to make comparisons.
The scientists recognise that homes burning wood is not the only factor influencing air quality. Meteorological conditions are particularly important. Because of this, other measurements will also be undertaken by the NIWA team during the study, including using a ceilometer normally used at airports to measure cloud cover. In Rangiora, it will be used to measure the height up to which pollution is transported.
A helikite will also be deployed to observe whether pollutants are being trapped in air layers. And temporary meteorological stations will be set up around the outskirts of the town to capture changes in wind speed and direction, both critical to understanding the dispersion of woodsmoke.
All of which will help NIWA scientists understand and explain how and why Rangiora’s air quality differs through winter.
“Over the next few winters we hope to scale-up to a larger project in Rangiora and to expand to larger or more complex towns. The longer term goal is to make predictions about air quality for both Rangiora and other towns, and how different management options could change it,” Dr Longley said.
For more information check out the CONA project page:
Dr Ian Longley
NIWA air quality scientist
Ph 09 375 2096