Changes in Season to Possibly Bring in More Hazy Days in Shenzhen
Hazy days are expected in the future as the city’s primary air pollutants will shift from ozone to PM 2.5 during the Autumn season. Cities in the Pearl River Delta including Guangzhou and Shenzhen has moderate air pollutions levels last week because of high concentrations of ozone.
Previous data recorded showed that ozone was the primary air pollutant in Shenzhen during the summer, and as temperature drops particulate matter will replace ozone as the main air pollutant. The director of the Shenzhen Environmental Monitoring Center said that the level of particulate matter or PM2.5 has a diameter of 2.5 microns or less which increase during fall because of seasonal air conditions. The cold air from the north moves south bringing microscopic air pollutants to Shenzhen, while hot air will be coming into the city from the southeast. These make fine particles in the air to disperse slower in such conditions.
Vehicle emissions is one of the major source of air pollution, emissions from boilers, manufacturing centers and constructions sites also contributes to the level of particulate matters in the air. Furthermore the dry weather during fall and winter blocks the dispersal of air pollutants and Shenzhen residents might see more of the haze in the coming months.