Delhi’s AQI to deteriorate as day progresses, says CPCB

The average AQI is predicted to be in the poor to very poor category on Monday, indicating the pollution levels are likely to rise further during the day

Delhi’s air quality index (AQI) improved significantly on Monday morning and stood in the moderate category at 8am. According to the data shared by Central Pollution Control Board (CPCB), the hourly AQI at that hour stood at 173.

Vehicles on Signature bridge during a cold and foggy morning, in New Delhi. (File photo)

However, the average AQI is predicted to be in the poor to very poor category on Monday, indicating the pollution levels are likely to rise further during the day.

On Sunday, the average 24-hour AQI in the national Capital stood at 305 in the very poor category. This could be attributed to Saturday’s rainfall which increased moisture in Delhi’s air, pushing the pollution levels to the very poor category.

On Saturday, the AQI was recorded 356, also in the very poor zone. This was a deterioration from Friday’s 295, which is categorised as poor in the AQI scale.

Union ministry of earth science’s air quality monitoring centre, System of Air Quality and Weather Forecasting and Research (SAFAR), said in the aftermath of Saturday’s western disturbance, high moisture availability with higher air holding capacity and dense fog formation are expected over Delhi, mainly during early morning hours.

“This can trigger heterogeneous aqueous reactions to form secondary aerosols (pollution particles converting into secondary aerosols with the help of water content in the air), which can lead to deterioration of AQI,” the forecast read.

“AQI is likely to improve from the lower end of very poor to the higher end of poor category for Sunday and Monday. It is likely to marginally deteriorate and drop to the lower end of the very poor category on Tuesday,” Sunday’s forecast added.

India Meteorological Department (IMD) forecast said that dense fog was also likely early Monday, which could reduce visibility levels drastically.

“The air quality is likely to remain in poor to lower end of very poor category on December 15. The air quality is likely to remain in poor to lower end of very poor category till December 17 and marginal deterioration is likely to start from December 18,” the IMD forecast added.

At the Safdarjung observatory, the minimum temperature on Sunday was recorded 11.1 degrees Celsius, three degrees above the season’s normal. The maximum temperature was 20.7 degrees Celsius, three notches below normal. Minimum and maximum temperatures are likely to remain in the same range on Monday as per the forecast.