Chennai: Delhi’s air quality was marked in the ‘very poor’ category on Wednesday morning, with pollution levels entering the ‘severe’ zone in neighbouring Ghaziabad and Greater Noida.
The Air Quality Index (AQI) was 381 at 9 am. The 24-hour average was 367 on Tuesday. It was 318 on Monday and 268 on Sunday. Ghaziabad and Greater Noida recorded an AQI of 430 and 410. There is a possibility of the air quality reaching ‘severe’ category between December 4 and December 7
According to IMD officials, the maximum wind speed is expected to be 12 km per hour on Wednesday, according to the India Meteorological Department (IMD). The minimum temperature was 8.2 degrees Celsius on Wednesday and the maximum is expected to settle around 27 degrees Celsius, the weather department said. The minimum temperature this season has remained 2-3 degrees Celsius below normal in the absence of cloud cover on most days.
The predominant wind direction remained westerly-north-westerly on most of the days. These winds blow from snowcapped western Himalayas towards the plains. Another reason for the below normal temperatures is La Nina, a phenomenon associated with the cooling of Pacific waters and an antithesis to El Nino.
Calm winds and low temperatures trap pollutants close to the ground, while favourable wind speed helps in their dispersion. The central government’s Air Quality Early Warning System for Delhi said the air quality is likely to remain in the upper end of the ‘very poor’ category due to unfavourable meteorological conditions.
IMD has also said that there is a forecast of shallow fog for 4 and 5 December. The minimum temperature will go up and settle at 10-11 degrees Celsius in the coming days.