According to Central Pollution Control Board’s air quality monitoring data, the AQI of 357 recorded on Friday — three notches poorer than Thursday — was the highest recorded this winter.
The air quality index (AQI) in Delhi plunged to 357 on Friday, the worst this season, with northwesterly winds bringing in particulate matter from raging farm fires in Punjab, and adverse local meteorological conditions slowing down the dispersion of pollutants.
According to Central Pollution Control Board’s air quality monitoring data, the AQI on Friday — three notches poorer than Thursday — was the highest recorded this winter.
Though the average air quality remained in the ‘very poor’ zone (AQI 301-400), several areas in the city recorded ‘severe’ AQI (between 401-500). CPCB data showed that monitoring stations at Shadipur, Anand Vihar, Ashok Vihar, Jahangirpuri, Narela and Bawana recorded air in the ‘severe’ zone late Friday evening.
An 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“, and 401 and 500 “severe“.
Experts said that besides the change in wind direction and slower wind speed coupled with the dip in temperature, farm fires from Punjab and other neighbouring states also continued to contribute air pollution in Delhi. Satellite data from the Consortium for Research on Agroecosystem Monitoring and Modelling from Space (CREAMS) at the Indian Agricultural Research Institute (IARI) showed Punjab, Haryana and Uttar Pradesh recorded a combined fire count of 2,224 fires on Friday. Over 2,000 of these incidents were recorded in Punjab alone.
The early air quality warning system for Delhi-NCR has forecast that the air quality in the capital is likely to remain in ‘very poor’ category till Monday .
VK Soni, a scientist at the India Meteorological Department (IMD) who is part of the panel on the Graded Response Action Plan (Grap), said the number of fire counts has nearly doubled which would lead to further deterioration of the air quality on Saturday. “The fire count has nearly doubled today. As a result, there might be a further spike in air pollution on Saturday. However, the air quality will remain in the very poor category. The wind continues to be calm due to which the dispersion of pollutants is weak. Generally, during the evening and night, the wind remains calm. During the day time also, winds are slow,” said Soni.
According to the Union ministry of earth science’s air quality monitoring centre, System of Air Quality and Weather Forecasting and Research (Safar), the local surface wind speed will be around 6-8 km/hour till Monday due to which the dispersion of pollutants will be weak.
“Strong winds at transport level blowing from northwest direction from stubble burning areas are likely to transport pollutants to Delhi and its share in Delhi’s PM2.5 is likely to increase further. Air quality is likely to deteriorate but remain within very poor region for next three days,” the forecast said.
On Thursday, Delhi recorded an AQI of 354, the worst since January 21, according to CPCB data. The air quality in Delhi plunged into the very poor zone for the first time this month on October 24, the day Diwali was celebrated. It, however, improved the day after due to amenable weather conditions with a sunny day and windy conditions dispersing the pollutants quickly.