Delhi’s air quality improves but the relief is likely to be shortlived
Delhi’s air quality improved further on Tuesday morning, dropping into the lower half of the ‘very poor’ category after wind speeds picked up in the region from Monday onwards. The capital recorded an overall Air Quality Index (AQI) of 333 (very poor) at 7 am on Tuesday, down from Monday’s reading of 389 (very poor), as per the Central Pollution Control Board’s daily bulletin. Agencies have forecast the AQI to improve further during the day as wind speeds touch 20 km/hr, before calm wind conditions once again return over Delhi from Wednesday onwards.
“Local surface winds are likely to remain relatively high today which will increase dispersion of pollutants, leading to an improvement, the but AQI remains in the ‘very poor’ category. However, on December 1, wind speed and temperature are likely to decrease, reducing ventilation and leading to a slight deterioration of air quality,” said the System of Air Quality And Weather Forecasting And Research (SAFAR), a government forecasting body.
Delhi woke up to shallow fog on Tuesday morning, with the minimum temperature expected to be around 9 degrees Celsius, a notch below Monday’s minimum of 10.3 degrees Celsius.
“Wind speed ranged from 10-15 km/hr during the day, but calm wind conditions were back after 5pm. Delhi’s overall visibility ranged from 300 metres in the morning to 2,500 metres during the day, owing to smog and similar conditions,” said R.K Jenamani, a scientist at IMD.
Under the influence of a western disturbance, Delhi is also likely to record very light rain on Thursday, with the minimum temperature expected to increase to 12 degrees Celsius.
“There is a possibility of very light rain occurring in parts of Delhi on Thursday. This western disturbance will raise the minimum temperature,” Jenaman saidi.
In its forecast on Monday, the Early Warning System (EWS) for Delhi also stated that air quality was unlikely to improve beyond the ‘very poor’ category over the next five days due to unfavourable calm or slow wind conditions at night.
“Winds are likely to be relatively strong during Monday and Tuesday. On Wednesday, air quality is likely to deteriorate again due to calm winds, but it will remain in the ‘very poor’ category,” it said.