A thin layer of smog shrouded the city on Thursday, with the capital’s air quality dipping to the “very poor” category amid plummeting temperatures and an increase in stubble burning cases in neighboring states.
After two days of slight improvement, Delhi’s 24-hour average air quality index (AQI) stood at 311, according to Central Pollution Control Board (CPCB) data. On Wednesday, the air quality index was recorded at 202, as favorable wind conditions helped disperse pollutants. Al-Qaeda in Iraq had 291 on Tuesday and 309 on Monday.
On Thursday, 351 cases of stubble burning were recorded in Punjab, the second highest daily number in the pre-winter season. The highest percentage was recorded on November 1 when Punjab witnessed 442 cases of stubble burning.
Meanwhile, while Uttar Pradesh saw 200 cases of stubble burning, the number was 35 in Haryana, 83 in Rajasthan, 354 in Madhya Pradesh and none in Delhi.
Among the 254 cities monitored, Delhi ranked fourth in the list of most polluted cities on Thursday, while Rohtak topped the chart in the ‘very poor’ category with an air quality index of 348, according to the CPCB.
Stubble burning is expected to emerge as the largest contributor to Delhi’s PM2.5 concentration, with Al-Qaeda in Iraq likely to deteriorate to the ‘very weak’ category from Thursday, according to the Air Quality Early Warning System.
The contribution of stubble burning to PM2.5 in Delhi was estimated at 21.5% on Thursday, and is expected to rise to 36.9% on Friday, and 32.4% on Saturday – a sharp increase from just 1.2% on Wednesday, data released by the Decision Support System showed.
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Satellite data revealed 94 stubble burning incidents in Punjab, 13 in Haryana and 74 in Uttar Pradesh on Wednesday.
According to the air quality early warning system, wind speeds are expected to decrease to less than 10 kilometers per hour from the northwest direction during the evening and night hours on Wednesday. As a result, the AQI index is likely to remain in the “very weak” category between November 6 and 8, the forecast said. After straw burning, the transportation sector is expected to be the second largest contributor, accounting for 16.2% of pollutants on Thursday, 11.2% on Friday, and 12.3% on Saturday.
Delhi’s air remained in the ‘poor’ category for the last two days – November 4 and 5 – recording an air quality index below 300. Before that, the city was in the ‘very poor’ category, with readings above 300.
Meanwhile, Delhi witnessed the coldest night of the pre-winter season on Thursday, as temperatures dropped to 12.7 degrees Celsius – the first time this season when the minimum temperature dipped below 15 degrees Celsius.
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According to the India Meteorological Department, the night temperature in Delhi was three degrees below the seasonal average, marking a sharp decline from the 18.4 degrees Celsius recorded the previous day. The maximum temperature was recorded at 27.4 degrees Celsius, about 3.1 degrees Celsius below the normal rate.
Officials attributed this sudden cold to the cold northwesterly winds blowing over Delhi after fresh snowfall in the western Himalayas, coupled with the clear night sky that enhanced radiative cooling.
(Tags for translation) Delhi farm fires raging
