Delhi: AQI rises slightly, may plunge to ‘very poor’ by weekend
While the air quality is likely to improve marginally on Thursday with a change in wind direction, it is expected to plunge to ‘very poor’ over the weekend, government agencies said.Updated: Oct 22, 2020, 06:49 IST
With a rise in stubble burning in neighbouring states, Delhi’s air quality deteriorated slightly on Wednesday though remaining in the ‘poor’ zone. The Central Pollution Control Board’s (CPCB) 4 pm bulletin recorded the average air quality index (AQI) at 256, as against 223 the previous day.
While the air quality is likely to improve marginally on Thursday with a change in wind direction, it is expected to plunge to ‘very poor’ over the weekend, government agencies said.
According to the System of Air Quality and Weather Forecasting and Research (SAFAR), the union ministry’s air quality forecasting wing, the share of stubble burning in the neighbouring states of Punjab and Haryana in PM 2.5 levels (particulate matter with diameter less than 2.5 micrometers) rose to 15% on Wednesday, as compared to 8% the previous day.
“Air quality may improve by Thursday due to cleaner easterly wind intrusion. However, it is likely to deteriorate on October 23-24 on account of reduced wind speed and impact from stubble burning. Synergised stubble burning fire counts around Haryana, Punjab and neighbouring regions stood at 849. The Safar model estimate of stubble burning share in PM2.5 is 15% and is likely to reduce on Thursday owing to expected change in boundary layer wind direction,” the Safar forecast said.
Fumes from crop stubble burning in the northwest region travel to Delhi every winter, contributing to its pollution.
According to scientists at the India Meteorological Department (IMD), the wind direction is likely to change to northeasterly on Thursday and hence the impact from stubble burning may reduce. “We are expecting some deterioration in air quality with reduction in wind speed from October 23. The air quality may touch the lower end of very poor zone,” said VK Soni, head of the environment monitoring research centre of IMD.
IMD scientists said the average wind speed is likely to remain around 8-10 kmph and may even reduce further over the next 3-4 days. Slow winds and a drop in temperature are not favourable for dispersion of pollutants.
The minimum temperature on Wednesday settled at 14.3 degrees Celsius, four notches below normal. The maximum temperature was 35.2 degrees C, two notches above normal.
On Tuesday, Delhi recorded the lowest minimum temperature for October in more than a decade, dipping to 13.7 degrees C.