Air pollution’s cold wave connect: 3 ways frigid temperatures will add to
The AQI remained in the ‘very poor’ category on Sunday for the second consecutive day (Representative Image).   |  Photo Credit: iStock Images
- On Sunday, the overall AQI of Delhi was recorded at 334
- As the temperature falls, the air quality is expected to worsen
New Delhi: The air quality of Delhi was in the ‘very poor’ category on Sunday and the overall air quality index (AQI) was recorded at 334. The AQI remained in the ‘very poor’ category on Sunday for the second consecutive day. PM10 pollutants were recorded at 288 and PM2.5 pollutants were recorded at 164 on Sunday.
As the national capital gears up for colder days, it must also brace itself for increased pollutant levels as the two are related. Air temperature affects the movement of air and thus, the dispersion of pollutants.
The warmer, lighter air at the surface rises and the cooler, heavier air in the upper troposphere sinks. As a result of this process pollutants move from the ground to higher altitudes. The effects of inversion are strong at night, due to which, the air quality deteriorates at night.
Drop in ventilation index
Delhi’s ventilation index- a product of mixing depth and average wind speed is set to reduce as the temperature drops. A ventilation index lower than 6,000 sqm/second, with the average wind speed less than 10 kmph, reduces the dispersal of pollutants.
Burning of biomass
The level of PM2.5 is exceptionally high in winter as people often burn biomass to keep themselves warm. The fog also worsens amid the winters, leading to