Delhi: Wind acts as moderator, you can expect more relief in coming days

NEW DELHI: Air quality in the city improved marginally on Sunday after wind speed picked up during the day. Central Pollution Control Board’s data showed that the Air Quality Index (AQI) was 381 at 9am on Sunday, but the reading reduced to 349 at 4pm.

However, Air Quality Early Warning System for Delhi, a forecasting model under the Union ministry of earth sciences, said the air quality was likely to improve to poor-to-moderate category on Monday and Tuesday due to strong winds. The share of stubble burning to Delhi’s PM2.5 was just 8% on Sunday.
Track the pollution level in your city
According to Met officials, strong winds cause dispersal of pollutants. RK Jenamani, senior scientist at India Meteorological Department (IMD), said, “As predicted, winds in Delhi on Saturday reached 15-20 kmph between 11am and 1pm. Even visibility improved to 2,200 metres at Safdarjung, the city’s base weather station, and to 3,000 metres at Palam during this period. The visibility was 800 metres on Sunday morning.”
The wind speed remained better during the entire day compared with the past few days. VK Soni, head, environment and research centre, IMD, said, “Unlike the past few days, when the wind speed normally went down to nil in the evening, it was recorded at up to 6kmph at Safdarjung at 7pm, allowing dispersal of pollutants. As strong winds are expected for the next two days, significant improvement in air quality is predicted on Monday and Tuesday.”
IMD’s forecast shows that strong surface winds at the speed of 20-30 kmph are likely on Monday. Experts said after some providing relief to residents on Monday and Tuesday, the air quality is likely to start deteriorating from November 24 as wind speed is predicted to slow down.
System of Air Quality and Weather Forecasting And Research (SAFAR), the forecasting body under Union ministry of earth sciences, said, “Transport level winds coming from the favourable northwest direction are likely to become strong from Sunday night till November 23 noon. As farm fire counts are reducing rapidly, the share of stubble burning related pollutants to Delhi’s PM2.5 may remain negligible in spite of high wind speeds.”
“Relatively high surface winds and moderate mixing layer height results in efficient ventilation of near-surface pollutants. Drastic reduction in fire counts and increase in surface wind speed can improve the air quality to the lower end of the very poor category for the next two days. From November 24, there may be a drop in temperature as well as surface wind speed, which will lead to less dispersion of pollutants. However, transport-level wind speed is likely to reduce, keeping the air quality in the upper end of poor to lower end of very poor category. The impact of farm fires (count 181) on Delhi’s PM2.5 is negligible at 8%,” added SAFAR.