Air quality improves to ‘poor’ as winds push away pollutants

The air quality in the city improved on Monday, with Gurugram recording an air quality index (AQI) of 246 (‘poor’), an improvement from the AQI of 425 (‘severe’)

The air quality in the city improved on Monday, with Gurugram recording an air quality index (AQI) of 246 (‘poor’), an improvement from the AQI of 425 (‘severe’) on Sunday, as per the Central Pollution Control Board’s (CPCB) daily bulletin. Experts attributed the improvement to high-speed winds and rain on Sunday.

HT Image

On Monday, however, Gurugram was the most polluted city in the National Capital Region (NCR), even as the AQI in neighbouring Delhi, Noida, and Ghaziabad stayed in the same category. Gurugram’s AQI had plunged into the ‘severe’ zone of the CPCB’s AQI on Sunday, a day after Diwali, on account of extensive cracker bursting across the city.

The level of ultrafine particulate matter having a diameter of 2.5 microns or less (PM 2.5), the city’s primary pollutant, was 574.35 micrograms per cubic metre (µg/m³) on Monday, as per the CPCB’s air quality monitor at Vikas Sadan in Sector 11, almost at 10 times the permissible limit of 60 µg/m³.

According to the early air quality warning system for Delhi-NCR, the air quality is likely to remain in the ‘moderate’ category on Tuesday. The air quality is expected to deteriorate marginally and remain in the ‘moderate’ to ‘poor’ category on Wednesday.

Sachin Panwar, a city-based independent air quality scientist, said that the AQI is expected to deteriorate later this week due to a fall in temperature. “In the morning hours, we will once again see a peak in the level of pollutants due to thermal inversion as cold winds bring down the temperature. The mixing height will also come down,” said Panwar.

On Monday, the city recorded a maximum temperature of 24.5 degrees Celsius, while the minimum temperature was 13.9 degrees Celsius. Both the maximum and minimum temperatures are expected to hover in a similar range on Tuesday. As per the weekly IMD forecast, clear skies will prevail on Tuesday.

Navdeep Dahiya, a Rohtak-based meteorologist, said that temperature is expected to drop by several degrees between November 18-20. “The temperature has already started falling post the passage of the western disturbance. North-westerly winds from the snow-clad mountains will further bring down the temperatures in the coming days,” said Dahiya.