New Delhi: The India Meteorological Department (IMD) informed, on Tuesday, that the air quality of Delhi-NCR is expected to remain 'poor' in the coming 2-3 days as the wind speed and minimum temperature may not be favourable for a dip in air pollution levels.
"The air quality index will remain the same for the next 2-3 days at 'poor' or lower side of the 'poor' category. There is no formation of anti-cyclone as of now, due to which there won't be much changes in the air quality of Delhi-NCR. Even there are fewer chances of further deterioration of air quality," said IMD scientist RK Jeenamani while speaking to ETV Bharat.
As per the Ministry of Earth Science's SAFAR bulletin, the air quality index of Delhi was 252 on Tuesday.
An AQI between 0 and 50 comes under 'good' category, 51 and 100 as 'satisfactory', 101 and 200 as 'moderate', 201 and 300 as 'poor', 301 and 400 as 'very poor', while 401 and 500 under 'severe' category.
When asked about the impact of meteorological conditions upon the air quality, the IMD officer replied that calm winds in low temperature allow accumulation of pollutants. For dispersion of pollutants, high wind speed and fall of minimum temperature is required.
He said, "During stubble burning, the stability index at a surface level should be high and air quality can also improve by wind speed. Thirdly, the minimum temperature should be low for better air quality. These three conditions are not favourable in the next 2-3 days because of which air quality is expected to remain in the poor category."
He also asserted, "Even now, the stable boundary layer or ventilation is good during the afternoon because of clear sunlight at that time. Hence, the air quality deteriorates during the early morning."
As the air quality index is expected to further deteriorate in the coming weeks, Environment Pollution (Prevention and Control) Authority (EPCA) has also asked Uttar Pradesh and Haryana governments, on Monday, to close thermal power plants which don't meet the standards laid down in 2015.
According to the SAFAR bulletin on AQI update, the overall AQI has marginally improved and in the lower end of poor category as of today morning likely to deteriorate marginally but within the poor category. Under the factors affecting AQI, the local wind speed and ventilation is in 'moderate-unfavourable' condition.
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