AQI deteriorates in Delhi; no major change in temperature expected

Experts attributed the deterioration in air quality to calm winds and low temperatures.

Delhi’s air quality deteriorated on Saturday but remained in the ‘very poor’ zone for the second consecutive day. The city logged an air quality index (AQI) of 360 on Saturday, according to the Central Pollution Control Board’s (CPCB) 4 pm bulletin.

Vehicles ply on the Delhi-Gurugram Expressway amid low visibility due to smog on Saturday. (ANI)

On Friday, AQI stood at 314 in the ‘very poor’ category. An AQI between zero and 50 is considered ‘good’, 51 and 100 ‘satisfactory’, 101 and 200 ‘moderate’, 201 and 300 ‘poor’, 301 and 400 ‘very poor’, and 401 and 500 ‘severe’.

Experts attributed the deterioration in air quality to calm winds and low temperatures. Due to calm local surface winds, the dispersion of pollutants is low while the drop in minimum temperature aids the accumulation of pollutants that remain suspended at lower atmospheric levels.

According to the Union ministry of earth science’s air quality monitoring centre, System of Air Quality and Weather Forecasting and Research (Safar), AQI is likely to worsen due to low to moderate wind speed. “For the next three days, surface wind speed (8 to 16 km/h) and temperature (maximum temperature between 27 and 26°C and minimum temperature between 8 and 9°C) are likely to worsen AQI slightly,” stated the forecast.

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According to the early air quality warning system for the National Capital Region used by Commission for Air Quality Management for its forecasts, the air quality is likely to improve but will remain in the lower end of the very poor category on Sunday. “The air quality is likely to improve further and remain in the poor category on Monday and Tuesday,” added the forecast.

The maximum temperature on Saturday settled at 27.6°C, a degree above Friday’s temperature and three degrees above the normal, while the minimum temperature settled at 8.3°C, a degree below the normal for this time of the year. According to the India Meteorological Department’s weekly forecast, the maximum temperature is expected to hover around 27°C on Sunday while the minimum may touch 9°C. A clear sky with mist and shallow fog in the morning is expected in some places on Sunday, the forecast said.