New Delhi, Nov 4 Delhi could witness a sharp spike in pollution the day after Diwali, with weakening winds expected to trap pollutants over the national capital even as changing wind patterns may help disperse some smog on the festival day, weather experts said.
Moderate northwesterly winds from northwest Rajasthan are expected to prevail over the national capital until November 7, while light easterly winds are likely to set in from the night of November 8, potentially helping disperse pollutants to some extent on Diwali, said Mahesh Palawat of Skymet.
However, the situation could worsen on November 9 as easterly winds are expected to weaken further, leading to accumulation of pollutants and a possible spike in the Air Quality Index (AQI), he said.
In a post on X, Meteorologist Navdeep Dahiya also indicated that wind speeds could increase from the current levels of less than 5 kmph to around 10-20 kmph on November 6 and 7.
The increase in wind speed could help disperse smog across Delhi, Haryana, Punjab and Uttar Pradesh, with AQI levels potentially improving by 20-30 per cent during afternoon and evening hours and 10-20 per cent at night compared with current levels, he said.
However, Dahiya cautioned that winds could slow again between November 8 and 13 due to an approaching western disturbance, a period during which air pollution could reach its seasonal peak.
According to the Air Quality Early Warning System, Delhi’s air quality is likely to remain in the ‘very poor’ category on November 5 and deteriorate further to the ‘severe’ category between November 6 and 7.
The forecasting system attributed the deterioration to unfavourable meteorological conditions, with the ventilation index expected to remain below 6,000 square metres per second and average wind speed below 10 kmph, both of which hinder the dispersion of pollutants.
Manoj Kumar of the Centre for Research on Energy and Clean Air (CREA) said that if weather conditions remain unchanged, air quality could deteriorate further as Diwali celebrations and related activities typically begin two days before the festival.
“The AQI could move from the very poor to the severe category. Areas currently recording poor air quality could slip into the very poor category, while those already in the very poor category could turn severe,” he said.
He added that the period also coincides with the peak stubble-burning season, with a rise in farm fire incidents being reported over the past two days. The increasing contribution of stubble burning, along with emissions from firecrackers and vehicular pollution, could further aggravate the situation. Several pollution hotspots could record AQI levels above 450, he said.
Kumar noted that November 9, the day after Diwali, could be particularly concerning, with Delhi’s air quality likely to slip into the severe category. He stressed the need for stricter implementation of GRAP measures during this period, given the combined impact of stubble burning, firecracker emissions and transport-related pollution.
(PTI News)
