The Air Quality Index was recorded at 483 as of 11 a.m., which is just short of the severe plus category
Air pollution levels bordered on the “severe plus” threshold for the Capital here on Sunday morning after a brief spell of respite due to a light drizzle on Saturday.
The AQI, at 11 a.m., was recorded at 483 which is just short of the severe plus category which commences at an AQI threshold of 500. The situation is expected to persist till the early hours of Monday following which some respite is likely.
An AQI between 0-50 is considered ‘good’, 51-100 ‘satisfactory’, 101-200 ‘moderate’, 201-300 ‘poor’, 301-400 ‘very poor’ and 401-500 ‘severe’. Above 500 falls in the ‘severe plus’ category.
According to a SAFAR forecast at 10 a.m., the unexpected light drizzling on Saturday night in a calm wind condition “worked highly adversely” in deteriorating the air quality. The season’s highest level of AQI of PM 2.5 was recorded on Sunday.
This, according to the forecast, was because rapid secondary aerosol formation started in the early hours of the day.
“Drizzling made air-holding capacity high and the mixing layer height became season’s lowest (~50 m) as observed by SAFAR-Celiometer data, which aggravated the situation further,” the forecast read.
“The AQI is expected to remain in ‘severe’ category till early November 4, but likely to recover further later in the day to the upper end of ‘very poor’,” the forecast added.
Thirty-two flights were diverted from Delhi airport on Sunday morning due to low visibility caused by pollution, airport officials said.
An Air India spokesperson said, “Due to bad weather, flight operations affected since morning 9 a.m. in T3 airport (Delhi). Twelve flights are diverted to Jaipur, Amritsar and Lucknow.”
When asked if it can be said that “bad weather” is actually the pollution, the spokesperson replied in affirmative.