Delhi pollution: QI improves, down to very poor after a week

The toxic smog hovering over Delhi lifted on Tuesday morning with bright sunshine and wind speeds aiding dispersion of pollutants, and pollution levels coming down considerably from "severe" to "very poor" category after almost a week. This will bring a huge relief to the population grappling with toxic air and also a brief respite to policymakers struggling with ways to control this emergency air pollution. According to Safar India, the overall air quality index in Delhi has hit 381, much below the 600 plus levels in the last few days.

Even the main pollutants level has dropped. PM 10 is at 307 in the poor category and PM 2.5 at 221 in the very poor category. According to a Safar India forecast, significant improvement in hourly value started on Monday morning as sun rays penetrated, however, the 24 hour running average will come down only slowly.

The AQI reduced magnitude will only be realized by Tuesday to the upper end of "very poor". High surface and boundary layer wind are expected for Wednesday as well which will also improve air quality. A fresh Western Disturbance is approaching north India and scattered rainfall and change in wind direction is expected by November 8 in Delhi region likely to positively influence the Air Quality India.

Over vthe past few days, a rapid secondary particle built-up along with the lowest mixing layer depth due to high cloud coverer blocking solar radiation had prevented dispersion in spite of not so calm surface winds.