Pollution levels dip as wind speed picks up in Delhi

The air quality of Delhi, which had been deteriorating since Saturday afternoon, improved significantly on Tuesday.

Experts said that the wind suddenly picked up speed, helping the pollutants to disperse faster. It also flushed out the moisture that had been trapping the pollutants.

The day’s average Air Quality Index, which had shot up to 352 on Sunday and further to 361 on Monday, dropped to 307 on Tuesday. An AQI value between 301 and 400 denotes ‘very poor’ levels of pollution.

Around 8 pm, the AQI dropped to 299. An AQI value below 300 is considered poor.

Pollution levels in some areas like DTU, Anand Vihar and RK Puram, which had hit the severe zone on Monday, improved and returned to very poor levels.

“As the wind speed increased, it flushed out pollutants and moisture. With a clear sky and the sun shining brightly, the mixing height increased, allowing the pollutants to disperse faster,” said D Saha head of the air quality laboratory at Central Pollution Control Board.

The sun’s rays helped the day temperature to increase marginally. The maximum temperature, which had dropped to 26.5 degrees Celsius on Sunday, increased to 28.4 degrees Celsius on Tuesday. The night temperature was 8.6 degrees Celsius on Tuesday.

As the moisture level dropped, the chances of fog became remote. The regional weather forecasting system had earlier forecast foggy mornings over the next few days.

On Tuesday, the Met experts said Delhi could at the most experience some mist or shallow fog in the morning Thursday and Friday. .

SAFAR, the country’s official pollution forecasting system maintained by the union ministry of earth sciences, has said air quality could deteriorate again over the next two to three days.

“The air quality could deteriorate once again. It would turn worse particularly on November 30. Chances are, however, remote that it would hit severe levels,” said Gurfan Beig project director of SAFAR.

First Published: Nov 28, 2017 23:43 IST