Delhi’s air very poor, may turn severe: IMD

Delhi’s air quality plunged to the far end of the ‘very poor’ zone on Friday as the wind speed and pattern changed, resulting in the slow dispersion of pollutants. At least 17 of the 35 monitoring stations had turned deep red, reaching the ‘severe’ zone on Friday.

The air quality index (AQI) is likely to deteriorate further over the next two days and may touch ‘severe’ by Saturday, government agencies have forecast.

According to the Central Pollution Control Board’s (CPCB) 4 pm bulletin, the AQI was 382, higher than 341 on Thursday. It was 373 on Wednesday. Most monitoring stations that are in ‘severe’ category include hot spots such as Anand Vihar, ITO, Vivek Vihar, Ashok Vihar, Bawana, Narela and Mundka, among others.

According to weather scientists at the India Meteorological Department, with stubble burning incidents being negligible at present, local pollutants that have accumulated in the atmosphere have not been able to disperse because of unfavourable weather conditions.

Kuldeep Srivastava, head of IMD’s regional weather forecasting centre, said the wind speed was just around 6-7 kmph during the day, which is not favourable for dispersal. “Besides, the wind direction changed to easterly from northwesterly. Whenever there is a change in wind direction, it impacts the air quality as winds turn calm for a while and do not allow dispersion. The night temperature is also below normal, which again is not favourable for dispersion. There was increased moisture because of easterly winds, which traps pollutants close to the ground,” Srivastava said.

He said the air quality may turn ‘severe’ over the weekend and any improvement is likely only after December 7 when northwesterly winds are likely to return.