Air quality begins to dip, mercury to drop from Thursday

Noida: The air quality of Noida and Ghaziabad on Wednesday deteriorated again, slipping into ‘poor’ category or worsening within ‘moderate’ levels as the weather

Noida: The air quality of Noida and Ghaziabad on Wednesday deteriorated again, slipping into ‘poor’ category or worsening within ‘moderate’ levels as the weather conditions begin to change. The unfavourable weather conditions from Wednesday night onwards will lead to further worsening of the air quality in the region, according to the Central Pollution Control Board (CPCB).

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The three cities of Noida, Greater Noida and Ghaziabad had been seeing ‘moderate’ air quality for the past two days – a major improvement over ‘severe’ levels on January 1 and 2. However, the western disturbance – which is now wearing out – led to drastic improvement of air quality and raised the mercury due to the cloudiness.

On Wednesday, the air quality of Noida slipped within ‘moderate’ category, while that of Ghaziabad and Greater Noida became ‘poor’.

According to the Central Pollution Control Board (CPCB), the air quality index (AQI) of Noida on Wednesday was 200 which is still ‘moderate’ against 149 a day earlier. However, Greater Noida’s air turned ‘poor’ with an AQI of 239 against 120 a day earlier, while AQI of Ghaziabad was 234 or ‘poor’ against 140 or ‘moderate’ a day earlier.

Weather experts said that the mercury is set to fall and the region to see dense fog in the coming days as the wind directions changed back to icy-cold north-westerly from the warmer easterly.

According to the India Meteorological Department (IMD), Noida recorded 1.5mm of rainfall on Wednesday against 5mm a day earlier. The average rainfall across NCR was 4.5mm based on the Safdarjung observatory against 4.7mm a day earlier. The weather department has said that the mercury will start falling from Thursday onwards this week.

“The wind directions have changed from easterly to north-westerly, which will lead to drop in mercury from Thursday onwards. The minimum temperature may fall by 4 degrees Celsius over the next 24 hours,” said Kuldeep Srivastava, head of regional weather forecasting centre, IMD.

On Wednesday, the minimum temperature for Noida was recorded at 14.9 degrees Celsius same as a day earlier. The maximum temperature for Noida was recorded at 21.1 degrees Celsius, against 22.3 degrees a day earlier.

For NCR, the average minimum temperature was 13 degrees Celsius and maximum was 21.6 degrees.

“The mercury is set to fall that traps the pollutants, and the change in wind directions leads to calm winds for a day. So, in both the cases the ventilation will worsen and pollution levels spike,” Srivastava added.

The major pollutant PM2.5 levels which continued to be under check for the past three days deteriorated to almost twice the standard limits.

The PM2.5 levels in Noida worsened to 102.02 microgrammes per cubic metres (µg/m³) against 72.6 µg/m³ a day earlier. The PM2.5 for Greater Noida was 110.97 µg/m³ against 78.75 a day earlier. The PM2.5 levels for Ghaziabad was 106.86 µg/m³ against 71.50 µg/m³ a day earlier.

According to the System of Air Quality and Weather Forecasting and Research (SAFAR), AQI will deteriorate over the next two days and may slip towards ‘very poor’ by the weekend. “Rain observed over many places in the Delhi region kept AQI in check which has touched its low and further improvement is not expected now. Surface North-easterly winds are slowly getting moderate and Ventilation condition is likely to become unfavourable for dispersion. SAFAR model predicts a gradual deterioration of AQI in the coming days. AQI is forecasted to marginally deteriorate to the poor category tomorrow and deteriorate from the poor to the very poor category on the 8th and 9th of January,” said the SAFAR statement on Wednesday.