New Delhi: The air quality in the city improved slightly on Saturday and logged AQI in the ‘very poor’ category after remaining in the ‘severe’ range for four days. The index read 370 against 429 a day earlier. However, Met experts said the pollution is likely to turn severe again on Sunday.
The air quality improved because wind speed picked up during the day. “The wind speed on Saturday noon was 9-12kmph compared with 6-7 kmph a day earlier at the same time,” noted Mahesh Palawat, vice-president, Skymet Meteorology. “Even the wind direction changed to north-westerly. As south-easterly winds were earlier blowing in the city, they were bringing moisture to Delhi, which caused pollution to be trapped within the city.” He explained that the air improved on Saturday because of this increase in wind speed, which helped in the dispersion of pollutants, and the change in wind direction.
Central Pollution Control Board put the AQI at 398 at 7am at the higher end of the ‘very poor’ level but it dipped to 370 at 4pm. An AQI of 50 or below is classified as good, while readings between 51 and 100 fall in the ‘satisfactory’ category, and those between 101 and 200 are classified as ‘moderate’. ‘Poor’ air ranges from 201 to 300, ‘very poor’ from 301 to 400 and ‘severe’ from 401 to 500.
According to the Air Quality Early Warning System for Delhi, the forecasting body under the Union earth sciences ministry, the air quality is likely to be in the ‘severe’ zone on Sunday, but improve to ‘very poor’ on Monday and Tuesday. “A feeble western disturbance is expected to impact the region from Sunday. It may lead to a dip in wind speed, which may cause accumulation of pollutants,” said Palawat.
India Meteorological Department has predicted very light rain or drizzle on Monday under the influence of a western disturbance. Another western disturbance is expected to impact north-west India from Dec 26, and IMD has predicted light rain on Dec 26. Light to moderate showers are likely on Dec 27.
Moderate fog was reported at Safdarjung, the city’s base weather station, with the lowest visibility of 200 metres from 7.30am to 8am. The maximum temperature was 23.4 degrees Celsius, one degree above normal. The minimum temperature stood at 7.6 degrees Celsius, one below normal.
