Delhi’s air quality remains ‘severe’ for 2nd straight day

Forecasts show winds are likely to marginally pick up on Wednesday, and the AQI is expected to improve to the “very poor” category

Delhi’s air quality remained “severe” for a second straight day as a smog hung over the city, keeping pollutants trapped close to the surface due to dipping temperatures. The 24-hour rolling average air quality index (AQI) was 413 at 8am, marginally lower than the 4pm reading of 428 on Tuesday, when the Central Pollution Control Board (CPCB) releases its daily national bulletin.

On Tuesday, Delhi recorded the worst AQI since December 19 last year. (ANI)

On Tuesday, Delhi recorded the worst AQI since December 19 last year, when it was 451, prompting the Commission for Air Quality Management (CAQM) in NCR and Adjoining Areas to implement measures under Stage-3 of the Graded Response Action Plan (Grap).

Forecasts show winds are likely to marginally pick up on Wednesday, and the AQI is expected to improve to the “very poor” category.

Experts said dipping temperatures and a drop in wind speed have led to inversion and the deterioration in the air quality. Inversion is characterised by a layer of warm air on top of cooler air, trapping it. The warm layer tends to lock in the smog close to the surface, creating a visible haze as pollutants are not able to disperse.

Private forecaster Skymet Weather vice president Mahesh Palawat said winds picked up post noon on Tuesday, touching up to 12 km per hour after starting to drop on Monday and becoming almost calm through the night. “Dipping temperatures led to significant accumulation of pollutants.”

He said winds are expected to stay consistent on Wednesday. “So there is a chance of marginal improvement in the air quality.” Winds are likely to reach 20 km per hour during the day on Wednesday.

Data from CPCB’s Sameer app showed that out of the 39 active ambient air quality monitoring stations in the city, 32 of these were in severe on Tuesday. Under the Grap-3, private or non-essential construction is prohibited. There are restrictions on private BS-3 petrol and BS-4 diesel four-wheelers in Delhi, Gurugram, Faridabad, Ghaziabad, and Gautam Budh Nagar. Schools, until class five, will operate in “hybrid” mode.