Delhi's air quality improved but Air Quality Index (AQI) recorded 'severe' with 467 on Monday. As fresh western disturbance will approach soon, AQI predicted 'Very Poor' for Tuesday.
Slight rise in wind speed and drizzle on Sunday evening improved air quality significantly. Day after the thick blanket smoke covered sky, Delhiites, witnessed bright sunny day and due to solar radiation, the dispersion of Suspended Particulate Matters (SPMs) took place.
According to environment scientists, rain improved air quality but light drizzling in calm wind conditions acted as medium towards increasing air -holding capacity triggered secondary particle formation contributed escalating in Particulate Matters 2.5.
In air quality forecast, PM 2.5 recorded 317 which was higher but better than previous day when AQI recorded 999 and PM 2.5 recorded above 1100 in different locations in Delhi.
Explain the mechanism of dispersion of pollutants, SAFAR scientist said that during cloudy days like -Sunday, in the absence of sufficient solar radiation, the mixed layer continued to be very low even during daytime, arresting pollutants firmly." "It is a unique condition because such a process is characteristic of the colder foggy period of December -January."
While MeT factors play pivotal role in improving air quality, SAFAR and Indian Meteorological Department (IMD) forecast strong surface winds and rains. "26 Kmph wind speed observed today early morning. High surface and boundary layer wind are expected for Tuesday also this will improve air quality to very poor level." "A fresh WD is approaching north India and scattered rainfall and change in wind direction is expecting by 8th November in Delhi region likely to positively influence AQI," the Ministry of Earth Sciences (MoES) said.
Meanwhile, values of both PM 10 and 2.5 were recorded 510 and 382 on National Ambient Air Quality Index (NAAQI). Overall AQI in Delhi was recorded at 438 at 4:38 am, The AQI at Alipur, Narela and Bawana were registered at 493, 486 and 472 respectively.
On Sunday, the national capital's average AQI stood at 494, the highest since November 6, 2016 when it was 497.
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.
In the National Capital Region (NCR), Noida (452), Ghaziabad (474) and Greater Noida (454), Gurgaon (396), Faridabad (426) were breathing extremely polluted air.
On Sunday, 21 of the 37 air quality monitoring stations recorded AQI between 490 and 500 with air quality sensors at Aya Nagar, Ashok Vihar, Anand Vihar and Aurobindo Marg peaking out at 7 PM.