Continuing its spell of 'bad air' days, the air quality in Delhi is likely to remain in 'poor' quality but will deteriorate further from Sunday to Monday.
The outlook for the subsequent seven days mentions that the air quality is likely to remain in 'poor' quality. This is for overall average even as some stations are already recording 'severe' air quality.
An Air Quality Index (AQI) between zero and 50 is considered 'good', 51 and 100 'satisfactory', 101 and 200 'moderate', 201 and 300 'poor', 301 and 400 'very poor'. AQI over 401 is considered 'severe'.
"The predominant surface wind is likely to be coming from northwest/west direction in Delhi with wind speed 10-18 kmph with mainly clear sky and heat wave conditions at a few places on Saturday," the Indian Institute of Tropical Meteorology (IITM), Pune - that runs the air quality early warning system for Delhi - said.
As reported by IANS on June 1, with PM10 as the lead pollutant, Delhi has faced a high pollution event in a modest pollution season resulting in AQI slipping to 'very poor' category on that day.
Year 2022 has proved to be worse compared to the previous four years. Between January 1 and May 31, the number of 'poor' air quality days is the highest since 2018, data from Central Pollution Control Board (CPCB) shows.
In 2022, for the duration from January 1 till May 31, there were as many as 63 per cent days with 'poor' AQI compared to 51 per cent in 2018, 39 per cent in 2019, 24 per cent in 2020, and 38 per cent in 2021.
On Saturday, at 3.00 p.m., the AQI at Anand Vihar in East Delhi was 343, Ashok Vihar in North Delhi was 209, Dwarka Sector 8 in West Delhi 314, Mandir Marg in Central Delhi 171, IGI Airport in Southwest Delhi 228, followed by Lodhi Road (169) and Siri Fort in South Delhi (219).
Meanwhile, the IITM forecast for Sunday and Monday said: "The predominant surface wind is likely to be coming from west direction in Delhi with wind speed 15-20 kmph, partly cloudy sky, heat wave conditions at isolated places and strong surface winds (speed 20-30 kmph) during the day on Sunday while on Monday, the predominant surface wind is likely to be coming from northwest/west direction in Delhi with wind speed 15-20 kmph, mainly clear sky and strong surface winds (speed 20-30 kmph) during the day."
The ventilation index is lower than 6000 metre square per second with average wind speed less than 10 kmph, it said, adding, it is unfavourable for dispersion of pollutants."
However, the long range transported dust will still have an impact on the air quality over parts of Rajasthan, Gujarat, Madhya Pradesh apart from NCR during the next two days.
