After being moderate after six weeks, air quality dips again in Noida, Ghaziabad

Favourable weather conditions ventilated or washed away the toxins from the area that had accumulated over past few weeks and that spiked on Diwali.

Noida: The air quality of Noida, Greater Noida and Ghaziabad fell back into the “poor” category after being in the “moderate” zone for one day.

According to the central pollution control board (CPCB), the air quality index (AQI) of Noida on Wednesday dropped to 207 or ‘poor’ against 178 or ‘moderate’ on Tuesday. (Hindustan Times)

Favourable weather conditions ventilated or washed away the toxins from the area that had accumulated over past few weeks and that spiked on Diwali.

Meanwhile, the India Meteorological Department predicted that temperatures is expected to drop as another spell of snowfall in the northern regions. Weather analysts believe that the fate of city’s air quality for at least next three days will depend directly on the number of farm fires in neighbouring states from where the winds are now entering the national capital region (NCR).

“The wind direction has changed from easterly to north-westerly on Tuesday night, which means that additional smoke is set to enter the region. Now even though the wind speed will increase over the course of next few days till November 22, the dispersion of pollutants will be difficult because the temperatures are also set to fall by three to four degrees in the same time. When temperatures are low the air becomes heavier and traps the pollutants well, making it difficult for winds to ventilate them easily. So the course of city’s air quality will depend on the number of farm fires in neighbouring states as well as the local emissions. The wind speed on Wednesday was around 6 kmph and this will increase and could reach upto over 15 kmph till November 22,” said Kuldeep Srivastava, head, regional weather forecasting centre, India Meteorological Centre (IMD).

On Wednesday, Noida recorded a minimum temperature of 14.8 degrees Celsius against 15.6 degrees a day earlier. The maximum temperature, as per the the automatic weather station installed in Noida was 24.5 degrees Celsius against 26.2 a day earlier.

“By November 19, the minimum temperature for this area could hover around 9 or 10 degrees Celsius because of good winds coming from well snowed mountains of Himachal Pradesh, Uttarakhand and Jammu and Kashmir,” said Srivastava.

According to the central pollution control board (CPCB), the air quality index (AQI) of Noida on Wednesday dropped to 207 or ‘poor’ against 178 or ‘moderate’ on Tuesday. The AQI of Greater Noida was 228 against 186 a day earlier. The AQI of Ghaziabad saw the worse drop amongst three cities falling from 166 on Tuesday to 236 on Wednesday.

The AQI between 0 and 50 is considered ‘good’, 51 and 100 ‘satisfactory’, 101 and 200 ‘moderate’, 201 and 300 ‘poor’, 301 and 400 ‘very poor’, and above 400 is ‘severe’.

The last time ‘poor’ category air quality was recorded in Noida was on November 2 with an AQI of 299, while the last ‘moderate’ air quality for Noida was recorded on October 06, when the AQI was 176

The pollution mass also aggregated marginally in the city due to plumage of additional smoke from farm fires in Punjab and Haryana where the winds are currently coming from. The PM2.5 levels in the past 24 hours in Noida dropping to 92.81 microgrammes per cubic meters (µg/m³) against 83.69µg/m³ a day earlier. The PM2.5 for Greater Noida also dropped to 101.79µg/m³ against 84.86µg/m³ on Sunday.

According to the System of air quality and weather forecasting and research (SAFAR), the AQI may improve drop towards Thursday.

“Surface winds are calm and boundary layer wind direction is North-Westerly (favorable for intrusion). Effective Stubble fire counts with sufficient potential estimated from SAFAR-multi-satellite products are marginally increased and are around 427...The AQI is likely to marginally deteriorate and forecasted to be in moderate to the Poor category for tomorrow. AQI is forecasted to further deteriorate to the higher end of the Poor to the lower end of the Very Poor category on 20th and 21st November,” said a statement from SAFAR on Wednesday.