Cocktail of slow winds, stubble fires gives Delhi its worst November AQI

The month usually sees two western disturbances, which often bring rain and stronger winds that disperse pollutants. This year, however, there were none

- Jasjeev Gandhiok

NEW DELHI: Air quality in the Capital this year in November was the worst since the Central Pollution Control Board (CPCB) started maintaining detailed records in 2015, with average Air Quality Index (AQI) at 376. Delhi last breathed air this bad in November 2016, when the average AQI was 374.

The national capital also recorded the maximum of 11 days in November when the index rose above 400, which is classified as "severe” by the pollution watchdog, as it affects healthy people and seriously impacts those with prior illnesses.

Besides human activities like construction and transportation that leads to harmful emissions, unfavourable meteorological conditions worsened the situation. Delhi usually sees at least two western disturbances in the month, which often bring rain, but more importantly, stronger winds that help in dispersing pollutants. This year, there were none, according to RK Jenamani, a scientist at the weather office.

"A western disturbance can bring rain and also increase wind speed a day before it is approaching, and when it is departing too,” Jenamani said.