Delhi’s AQI remains ‘very poor’, improvement likely

VK SONI, THE HEAD OF IMD’S ENVIRONMENT MONITORING RESEARCH CENTRE, SAID AIR QUALITY IS LIKELY TO IMPROVE, BUT

WILL REMAIN IN THE “VERY POOR” CATEGORY FOR NEXT TWO DAYS

The national capital’s air quality was recorded in the “very poor” category on Friday, while government agencies said it is likely to improve slightly in the next 24 hours.

On Thursday, the city’s air quality had dropped to the worst levels since November last year, with farm fires accounting for 42 per cent of its pollution, the maximum this season so far.

Experts said unfavourable meteorological conditions - calm winds and low temperatures and smoke from farm fires in neighbouring states pushed the air quality index to the “severe” zone on Thursday, the first time since January.

However, higher wind speed picked up later, helping in dispersion of pollutants.

Delhi’s air quality index (AQI) stood at 397 at 10 am. On Thursday, the 24-hour average AQI was 450, the highest since

November 15 last year, when it was 458.

According to the India Meteorological Department (IMD), the maximum wind speed was 12 kilometres per hour on Friday and the minimum temperature 11.2 degrees Celsius.

Calm winds and low temperatures trap pollutants close to the ground, while favourable wind speed helps in their dispersion.

VK Soni, the head of IMD’s environment monitoring research centre, said the air quality is likely to improve slightly, but will remain in the “very poor” category for the next two days. The Air Quality Early Warning System for Delhi said the farm fire count in Punjab remained “very high” on Thursday and it is likely to impact the air quality of Delhi-NCR and other parts of northwest India.

The ministry of earth sciences’ air quality monitor, SAFAR, said the farm fire count in Punjab, Haryana, Uttar Pradesh, Uttarakhand, and neighboring areas increased significantly and stood at 4,135 on Wednesday, the highest this season so far.

SAFAR said the boundary layer wind direction is northwesterly - favourable for the transport of pollutants from farm fires.

“The share of stubble burning in Delhi’s PM2.5 pollution was estimated at 42 per cent for Thursday,” it said.