City air still ‘severe’; no improvement till next week

The air quality in the city remained in the “severe” category for the second consecutive day on Sunday with a reading of 434 on the Central Pollution Control Board’s

The air quality in the city remained in the “severe” category for the second consecutive day on Sunday with a reading of 434 on the Central Pollution Control Board’s (CPCB) air quality index (AQI) bulletin. Saturday’s reading is only a few points below the previous day’s AQI reading of 439, also in the “severe” category. An AQI reading between 401 and 500 is categorised as “severe” and can cause distress and respiratory complications, especially for children and senior citizens, as per air quality experts.

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The average daily concentration of particulate matter (PM) 2.5 — the city’s most prominent pollutant — on Sunday was 436.95µg/m³, as per the HSPCB’s official air quality monitor at Vikas Sadan. Officials and experts attributed the spike in pollution to poor dispersion of pollutants and farm fires.

According to the early air quality warning system for Delhi-NCR, the air quality is likely to remain in the “severe” to “very poor” categories on Monday. Air quality is expected to persist in the same category on Tuesday as well. As per the warning system, a high count of farm fires was adversely affecting the air quality in Delhi-NCR. Further, average wind speed less than 10 kmph was not favourable for the dispersion of pollutants. Calm winds with speed up to 5-8kmph are expected to prevail on Monday.

Experts said that due to the prevalence of slow wind speed, a significant improvement in air quality was not on the cards. Navdeep Dahiya, a Rohtak-based meteorologist, said that due to the prevalence of calm winds along with other factors, pollutants couldn’t be dispersed. “The wind speed didn’t pick up significantly due to which there was no significant impact on the AQI. High-speed winds are needed for the dispersal of pollutants due to the layer of fog that has enveloped,” said Dahiya. He said that continuing stubble burning, along with temperature inversion, was also contributing to the high pollution levels.

Dahiya said that no significant improvement in air quality was expected until Diwali. “There is stability in the atmosphere. There is no immediate western disturbance or weather system that might help in the improvement,” he said.

On Sunday, the city recorded a minimum temperature of 13 degrees Celsius, three degrees below the normal. The maximum temperature on Sunday was recorded at 27.5 degrees Celsius, two degrees below Saturday’s 29.9 degrees Celsius. The minimum temperature is expected to hover around 13 degrees Celsius on Monday while the maximum temperature is expected to be around 29 degrees Celsius. Clear skies are expected to prevail this week with fog and mist in the morning hours, as per the IMD’s weekly forecast.