Delhi pollution: Air Quality Index docks at 'Poor' category, rain likely on Tuesday

The air quality in the national capital and areas around deteriorated on Tuesday with the Air Quality Index (AQI) reaching the mid of the 'Poor' category. The city has been reeling under severe air pollution since the fag-end of October. In the morning the Air Quality Index (AQI) in Delhi docked at 242, according to the Center-run System of Air Quality and Weather Forecasting And Research (SAFAR).

The AQI was recorded the highest in Chandni Chowk at 302, followed by IIT Delhi at 266, Airport (T3) at 264, Mathura Road at 263, Dhirpur at 235, Ayanagar at 234, Pusa at 228, Lodhi Road at 217, and Delhi University at 215. The AQI in Noida stood at 211 and Gurugram at 252. 

The dip in the air quality took place due to slowing down of Delhi surface winds. As per SAFAR, there is a possibility of shower on Tuesday which may improve the air quality if sufficient rain occur. The AQI for November 27 has been forecasted to remain in the 'Poor' category.

The fire counts as per SAFAR multi-satellite product estimate is 463 which is sufficiently high and wind arriving in Delhi is from the north but fire contribution in Delhi's air quality is marginal. This is due to very high upper air transport level winds which may surpass the plume without descending in Delhi. It is an ideal example that fire counts are not directly proportional to deterioration of Delhi's AQI and meteorology playing a decisive role.

An AQI between 0-50 is considered `good`, 51-100 `satisfactory`, 101-200 `moderate`, 201-300 `poor`, 301-400 `very poor` and 401-500 is marked as `severe`. An AQI above 500 falls in the `severe plus` category.

During winter each year, most of northern India suffers from a spike in toxicity in the air due to the change in weather patterns and crop residue burning in the neighbouring states of Haryana, Punjab and Uttar Pradesh.