Delhi’s air quality to deteriorate briefly before improving
Delhi’s air on Wednesday felt the positive impact of strong winds that blew over the city the previous day, with pollution levels in the Capital improving to the ‘poor’ category for the first time in six days.
Data from the Central Pollution Control Board (CPCB) showed that Delhi’s average air quality index (AQI) value on Wednesday was 297, down marginally from Tuesday’s 312.
India Meteorological Department (IMD) scientists explained that even though winds were calm on Wednesday, Delhi’s pollution cleared up significantly in the first half of the day because of the impact of Tuesday’s strong winds. Noon onwards, however, the air quality began to dip and the AQI settled just a few points short of the ‘very poor’ zone.
Kuldeep Srivastava, head of IMD’s regional weather forecasting centre, said the average wind speed over Delhi was around 4kmph on Wednesday.
“The wind speed was around 4kmph during the day, but calmed after sun down. The impact of this will be seen on Thursday as well. The wind speed will remain low and air quality will deteriorate, but remain in the very poor zone,” Srivastava said.
VK Soni, head of IMD’s environment monitoring research centre, also said air quality is likely to deteriorate further on Thursday. However, he predicted that the city’s air will improve significantly between Friday and Sunday, with wind speeds likely to touch 15kmph on Friday.
“There is a trough formation, which will lead to a significant improvement in wind speed over the Capital and this will lead to better dispersion of pollutants. Till Sunday, the forecast is that we will see an improvement in air,” Soni said.
Meanwhile, stubble burning in Punjab and Haryana continued to add to Delhi’s pollution on Wednesday. The Union ministry of earth sciences’ air quality monitoring centre, System of Air Quality and Weather Forecasting and Research (Safar), said 1,830 fires were spotted over Punjab and Haryana on Tuesday, contributing to 18% of the Capital’s PM 2.5 (ultrafine particulate matter with diameter less than 2.5 micrometers) levels.