Abstract:
Air quality in Auckland is generally within the national guidelines. But at times,
especially in winter, the city suffers from air pollution phenomena such as a brown
haze, which is thought associated with high levels of nitrogen oxides. The effects of
meteorological conditions on local air quality are quantitatively assessed on a daily
basis by determining the relationship between concentrations of nitrogen oxides (NO
and NO2) and several meteorological variables for winter months, from 1990 to 1996.
Strong southwesterly winds, the prevalent flow pattern over the region, are associated
with good air quality due to enhanced dispersion. Calm, cold conditions lead to the
build-up of pollution. Meteorological conditions can explain more variances in NO levels
(up to 65%) than in NO2 levels (up to 26%). For different emission source conditions,
the effects of meteorological conditions are consistent for NO levels, but are significantly
different for NO2 levels, suggesting other factors may be important.
