Air quality deteriorates, experts point to low temperatures, slow winds

Air quality in the city deteriorated to the very poor category on Thursday, recording an air quality index (AQI) reading of 354, as per the Central Pollution Control Board’s (CPCB) daily air bulletin

Air quality in the city deteriorated to the very poor category on Thursday, recording an air quality index (AQI) reading of 354, as per the Central Pollution Control Board’s (CPCB) daily air bulletin.

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The AQI fell sharply from a score of 276 the previous day, which indicated poor air and had marked Gurugram’s worst AQI reading this year. Officials and experts attributed the surge in pollution to low wind speeds, lack of sunlight and colder temperatures that began setting in earlier this week.

The minimum temperature in Gurugram rose marginally to settle at 4.9 degrees Celsius on Thursday morning, up from 4.6 degrees Celsius a day prior. The maximum temperature increased significantly, touching 18.2 degrees Celsius, up from 15.2 degrees Celsius a day prior.

The weather readings are according to the data from the India Meteorological Department’s automatic weather station in Delhi’s Palam area, which borders the city. Gurugram’s weather system has not been recording the temperature readings for several days now.

Experts pointed out that the increase in temperature hasn’t been able to stave off a deterioration in air quality, due to the lack of clear skies and wind speeds. “Conditions, right now, are extremely unfavourable for the dispersion of pollutants. This is not surprising since we have witnessed a western disturbance earlier this month. After the passage of a weather system, there is a stagnation period where winds slow down and the temperature falls, allowing dust to accumulate and remain suspended very close to the earth. There was some change in daytime temperature today, but not enough to get the winds moving again,” said Sachin Panwar, a city-based air quality scientist.

While two of the city’s four air quality monitors — at Teri Gram and in Sector 51 — did not record sufficient data to compute the AQI on Thursday, the Haryana State Pollution Control Board’s air quality monitor at Vikas Sadan in Sector 11 recorded an AQI of 410 (indicating severe air), while another monitor on the Gurugram-Faridabad Road recorded an AQI of 354 (indicating very poor air). The average daily concentration of finer particulate matter (PM2.5) at Vikas Sadan stood at 410ug/m3, up from 331ug/m3 on Wednesday and almost seven times the permissible limit of 60ug/m3.

As per the early air quality warning system for Delhi-NCR, “The air quality is likely to deteriorate and crossover from the upper end of very poor to the severe category on 15.01.2021. The air quality is likely to remain in the severe category on 16.01.2021. A slight improvement is expected on 17.01.2021.”