Near 'zero' wind speed adding to pollution woes
NEW DELHI: Sunday evening in the national Capital recorded nearly 'zero' wind speed, a far cry from the minimum wind speed of 12 miles per hour necessary for the city to clear off smog and polluted air.
Environmental experts said that until the wind speed improves, there is no chance of significant change in the pollution level.
Dipankar Saha, head of air laboratory division at Central Pollution Control Board (CPCB), said, "There is no wind movement. Moreover, the temperature is not coming down much, which could have resulted in the conversion of fog into water and subsequent dispersion of suspended particulates."
According to CPCB, temperature, wind speed, relative humidity and atmospheric boundary layer are the four major factors which determine air quality.
Severe change in these four areas is responsible for the sudden onset of pollution and worsening Delhi air.
Throughout Sunday, a thick layer of smog blanketed Delhi-NCR, even as reports claimed that air quality was slowly, but steadily, improving.
It has become hard for people in the Capital to breathe, with the city's Air Quality Index lingering in the 600-1,000 range.
Meanwhile, the Union Health Ministry has issued an advisory asking residents of the Capital to drink plenty of water and avoid areas with smoke or heavy dust.
At 9.00 am, average levels of PM10 were recorded at 671 µg/m³; while average levels of PM2.5 were recorded at 441.7 µg/m³.
Meanwhile, the Meteorological Department said there is a chance of light rain over Delhi-NCR on November 14 and 15, on the back of a weather disturbance hitting north India.