Delhi air remains polluted despite stronger winds

IMD scientists said strong winds helped clear accumulated pollutants, and the winds are expected to be favourable over the weekend.

Delhi’s air improved marginally on Friday as winds picked up speed and stubble fires from the neighbouring states of Punjab and Haryana contributed less to pollution in the national capital. The India Meteorological Department (IMD) has forecast that pollution levels will reduce further over the weekend.

Commuters drive along a highway amid hazy weather conditions, at Sarai Kale Khan in New Delhi on Friday. (Biplov Bhuyan/HT PHOTO)

Central Pollution Control Board (CPCB) data showed that Delhi’s overall air quality index (AQI) on Friday was 374, in the ‘very poor’ category, marginally better Thursday’s 395. However, on Thursday, the average hourly AQI for most of the day remained in the ‘severe’ zone.

IMD scientists said strong winds helped clear accumulated pollutants, and the winds are expected to be favourable over the weekend.

Kuldeep Srivastava, head of IMD’s regional weather forecasting centre, said the wind speed during the day remained in the range of 12-15kmph, which helped disperse pollutants.

“For a brief period the wind speed had even touched 16kmph. On Saturday, the winds will pick up more and we are expecting that the air quality index can even reach the poor zone,” Srivastava said.

He said that on Sunday too, weather conditions will remain favourable.

Union ministry of earth sciences’ air quality monitoring agency System of Air Quality and Weather Forecasting and Research (Safar) said that the number of stubble burning cases in Punjab and Haryana had also dropped to 1143 from 2912 a day before, which also brought some respite to the national capital.

“A significant improvement is forecasted for Sunday, when the AQI is likely to come down to the lower-end of very poor to poor category. The SAFAR synergized stubble fire counts significantly decreased and stood at 1143 on Thursday. Although the boundary layer winds direction is favourable for pollutant transport towards the region, improved ventilation conditions likely to bring down the concentration levels in Delhi,” the Safar summary said.

It added, “The stubble burning share in PM2.5 (ultrafine particulate matter with diameter less than 2.5 micrometers) decreased and is estimated to be 19% for Friday. In summary, increased surface wind speed and faster dispersion are likely to significantly improve the situation by Sunday.”