Rise in pollution, dip in mercury likely from first week of December: IMD
The city’s air got slightly worse on Sunday as a consequence of a marginal increase in farm fires in neighbouring states and slower winds over the National Capital Region (NCR), government agencies said.
As per the Central Pollution Control Board (CPCB), the average air quality index (AQI) was 256 on Sunday, up from 231 the previous day, both categorised as ‘poor’.
Meanwhile, weather scientists have forecast a further increase in pollution December 2 onwards, with temperatures expected to dip and winds likely to slow down.
Scientists at the India Meteorological Department (IMD) have forecast below normal minimum temperatures in parts of north and northwest India including Delhi this winter.
“The minimum temperature is likely to remain between 6-8 degrees Celsius over the coming week. Usually, such a drop in temperature is observed from December 20-22, but is likely in the first two weeks of the month itself this year. This may impact air quality, as winds are likely to get calm around December 4-5,” said Kuldeep Srivastava, head of IMD’s regional weather forecasting centre (RWFC).
On Sunday, the Safdarjung Observatory — readings from which are taken as representative of Delhi’s weather — recorded a minimum temperature of 7°C, three notches below normal. The maximum was 26.4°C, one above normal, while winds blew at speeds of between 8 and 10kmph.
“Wind speeds will remain around the same over the next couple of days, but will become slow from December 2 onwards,” he added.
As per IMD’s seasonal outlook for December to February released on Friday, nights and early mornings are likely to be chilly with below normal minimum temperatures over most parts of north, northwest and central and some parts of east India, while day temperatures are likely to be above normal over the same regions.
According to the System for Air Quality and Weather Forecasting and Research (Safar), the Union ministry’s air quality forecasting wing, the share of stubble burning to the city’s PM2.5 levels on Sunday rose to 6% from 4% the previous day. “The number of fire counts was 464. Ventilation conditions are likely to slow down from December 2 onwards and air quality is likely to deteriorate to “very poor” zone thereafter,” the Safar bulletin said.