Air quality improves significantly but stays severe

NEW DELHI: Delhi's pollution level remained 'severe' for the second day as a thick haze engulfed the national capital in early hours of Friday. However, the authorities said there was a significant improvement in the air quality compared to Thursday. According to the Central Pollution Control Board (CPCB), the overall air quality index (AQI) stood at 426 which falls in the 'severe' category.

However, the Centre-run System of Air Quality and Weather Forecasting And Research (SAFAR) said the air quality of the city has "improved significantly". According to SAFAR, the air quality is expected improve further and will become 'very poor' by afternoon and will improve further by Saturday. SAFAR said the contribution of PM2.5 in PM10 which was 75 per cent on Thursday (against normal 55 per cent) has also been reducing.

"The Delhi Air Quality has improved significantly since yesterday (8 Nov) but the recovery is slow due to low surface wind speed and it continued to be in the severe category. Latest SAFAR model results show a movement of cold front carrying heavy air mass towards Delhi region but with low wind speed at intrusion level," noted the SAFAR official.

The officials added that there is a possibility that wind speed nay pick up at the upper level, late in the night and push the level of pollution and keep it in the severe zone on Saturday with intense fog which will further help in trapping the pollutants. The temperature is likely to cool down. As per the satellite images, heavy fire counts were recorded in the last 24 hours but presently the contribution of stubble fire emissions is marginal as upper winds are Northerly.

An AQI between 0 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'. AQI above 500 falls in the 'severe-plus emergency' category. Delhi's air quality on Thursday went off the charts to 'severe plus' emergency category as smog caused due to smoke from firecrackers engulfed the national capital. The overall AQI on Thursday recorded in the "severe plus emergency" category at 642, according to the data by SAFAR.

'The sharp spike in pollution on Thursday was caused by rampant burning of firecrackers that had led to the formation of a smoky layer across the national capital and drastically reduced visibility, authorities said. Meanwhile, the Delhi government has banned the entry of trucks in the Capital for three days. The officials said that as the wind speed is low the effect of the ban is

yet to come.