Brown Haze in Auckland

Although Auckland's air is generally perceived to be good, if you press harder, many people tell a different story. Brown haze sometimes appears in the Winter months is Auckland from May-September from early to late morning. Temperatures have to be below 8-10 degrees with little wind of a morning haze to occur. The morning inversion holds the haze in the atmosphere. Scientists generally believe that brown haze is caused by Nitrogen Dioxide and particulate matter. The determining factors that cause Auckland's haze, both chemical and meteorological are currently a subject of research.

However brown haze has been directly linked to higher hospital admissions. The 11,000 litres of air we breathe per day is the key factor in many respiratory and cardiac illnesses in Auckland. There are approximately 15-30 days a year when pollutant levels in Auckland's air exceed our National Environmental standards. Most of the particulate matter in Auckland's air is attributed to motor vehicles and fuel burning in domestic fires.

Scientist, Nick Talbot at NIWA is currently engaged in a research project to determine the weather conditions that cause 'brown haze' using air quality instruments. Detailed information and fact sheets about haze and air quality are available on the Auckland Council website.

See http://www.arc.govt.nz/environment/air-quality/air-quality.cfm)

A recent WHO report surprised many Aucklanders with their findings about our air quality. Using a measurement of particulate matter per cubic metre of air, Auckland had an overall rating of 15pm compared to 12pm in Sydney and 13pm in Port Phillip Bay, cities with much larger populations.

See http://www.who.int/phe. (World Health Organization Report, September: Geneva, Switzerland, 2011).

Brown Haze from Cornwall Park, 2011. (JJ)