THIS DIWALI, AIR QUALITY WILL BE BETTER

This Diwali, Delhi’s air quality is likely to be relatively better than last year, when level of pollutants had reached perilous proportion, SAFAR, a Union government agency, has forecast.

The forecast was based on three scenarios — assuming that additional emissions (firecrackers) in 2017 are same as 2016, assuming that firecrackers reduced by 50 per cent, and assuming that no additional firecracker emissions (just normal emissions) happen.

In 2016, thick black smog engulfed the national capital for many days post Diwali fireworks.

Under the first two forecast scenarios by SAFAR (System of Air Quality and Weather Forecasting and Research), the highest levels of PM (Particulate Matter) 10 and PM 2.5 are expected between 11 am to 3 am on the night of October 19-20 and the air quality will only start to improve from October 21.

A repeat of 2016 smog is not likely mostly due to atmospheric conditions.

“Upper air winds which transport from distant sources (like IGP region or stubble burning regions) are quite low and unlikely to impact Delhi significantly, though direction is rapidly varying but predominantly north-easterly. Even if dominant upper wind direction is from NNW (stubble burning region), the contribution is less likely to be significant in Delhi with such light upper winds. Given the above scenario, the contribution of transport from distance sources is quite less so far. It is just due to horizontal spread rather than direct pumping,” said the report.

As per forecast, while the pollution will not peak in a similar manner this Diwali, the air quality will, however, continue to deteriorate.

“There is still a favourable condition for local pollutants to stay longer and stagnant within Delhi region before getting flushed out. Moisture in the air is increasing. This may increase atmospheric holding capacity of the emissions coming from firecrackers,” it said.