Delhi's air quality took a significant turn for the worse on Saturday, plunging deeper into the 'very poor' category. The 24-hour average Air Quality Index (AQI) climbed to 385, a notable increase from 332 recorded the previous day, as per data released by the Central Pollution Control Board (CPCB).
Rising Pollution and Meteorological Factors
The deterioration was driven by unfavorable weather conditions. Officials pointed to a combination of calm winds, fog, and low temperatures that trapped pollutants close to the ground. The AQI showed a worrying upward trend through the day, starting at 354 at 8 am and rising to 390 by 6 pm. An official explained that "wind was calm during the night and light during the day, contributing to the rise in pollution levels."
Localized Hotspots and Fog Conditions
The pollution was not uniform across the capital. Data from the city's 40 monitoring stations revealed that half of them, 20 stations, reported AQI levels exceeding 400 on Saturday evening. The worst-affected areas were Anand Vihar, which recorded a severe AQI of 446, and Vivek Vihar at 441.
Moderate fog enveloped the city, impacting visibility. The India Meteorological Department (IMD) noted that Safdarjung recorded the lowest visibility at 400 metres at 8:30 am, which improved slightly to 500 metres by 9 am. Palam experienced shallow fog with visibility of 800 metres. The IMD has issued a yellow alert for dense fog in isolated areas for Sunday morning.
Forecast and Seasonal Context
The Air Quality Early Warning System has predicted that Delhi's air quality is likely to remain in the 'very poor' range for the next several days. This season, Delhi has already endured seven 'severe' pollution days, with four of those occurring in December alone.
RK Jenamani, a senior scientist at IMD, provided context on the fog patterns, stating, "Delhi last saw dense fog on Dec 23, with mostly shallow fog reported since Dec 24." He added that the most intense fog this season was observed on December 15, 19, and 23. The IMD forecasts partly cloudy skies in the coming days, with a mainly clear sky expected on December 30.
Temperature-wise, Saturday saw a maximum of 22.2 degrees Celsius (two notches above normal) and a minimum of 7.8 degrees Celsius (one degree above normal).
