Weather elements help Delhi see cleanest January since AQI launch...
NEW DELHI: The capital saw its cleanest January this year since the Central Pollution Control Board (CPCB) started measuring the Air Quality Index (AQI) from April 2015 onwards, mainly owing to excess rainfall, fewer foggy days and seven western disturbances. The month’s average AQI stood at 279 against 324 in 2021. This January witnessed two rare ‘satisfactory’ days and one ‘severe’ day. Track the pollution level in your city Experts said when a strong western disturbance affects the region, it causes rain, rise in temperature and wind speed and helps in improving air quality. Rain activity was intense, making January 2022 the wettest in 121 years. Fog, which comes from Indo-Gangetic plains, carries a huge quantity of air particles. Fog formation also affects the boundary layer height and causes calm conditions by trapping pollutants,” said Gufran Beig, founder project director, SAFAR. CPCB data shows that two ‘satisfactory’ air quality days were recorded this January. In contrast, no such day was seen in January in the previous years. At three, this January also saw the highest number of ‘moderate’ days. According to CPCB, 26 out of 31 days this month had air quality in the range of ‘poor’ to ‘severe’ (AQI above 201). In comparison, there were 29 such days each in January 2021, 2019 and 2017; 31 each in 2016 and 2018; and 28 in 2020. “This January, there has been a significant decrease in the ‘severe’ and ‘very poor’ days compared to last year. This is because of intermittent rain, higher wind speeds to the tune of average 5m/sec and reduced and no severe foggy days,” said Dipankar Saha, former head of CPCB’s air laboratory, who analysed the past few years’ AQI for January. Pointing out that winter was about to end, Anumita Roychowdhury, executive director, Centre for Science and Environment, said “action for sustained change” must gather momentum. “Daily average levels of PM2.5 are bouncing back again. There has been rapid increase since January 28. The improved monthly average level of pollution this month seems to be the result of record rainfall and a cold spell for an extended period as well as more unique winter conditions. The impact of changing climate on air quality patterns will have to be understood better for interventions,” she said. Delhi had last year recorded its cleanest October and dirtiest November.
