Delhi’s air quality remains poor, likely to be same till Saturday

An AQI between zero and 50 is considered good, 51 and 100 satisfactory, 101 and 200 moderate, 201 and 300 poor, 301 and 400 very poor, and 401 and 500 severe

Delhi’s pollution levels remained in the poor category on Thursday morning with an Air Quality Index (AQI) of 281 at 7am. It was expected to remain the same until Saturday. On Wednesday, the average 24-hour AQI was 260.

An anti-amog gun on a modified vehicle being used to spray water to curb pollution in New Delhi. (PTI)

An AQI between zero and 50 is considered good, 51 and 100 satisfactory, 101 and 200 moderate, 201 and 300 poor, 301 and 400 very poor, and 401 and 500 severe.

On Wednesday, the Union earth sciences ministry monitoring agency System of Air Quality and Weather Forecasting and Research said unfavourable weak wind flow from stubble-burning areas was likely to reduce the inflow of pollutants to Delhi. It said stubble burning emissions contributed 5% to PM2.5 in Delhi.

“Fine particles (size < 2.5 micrometer) contribute ~ 59% to PM10. Local surface winds are 4 to 8 km/h for [the] next 2 days (Max Temperature 30-29 deg C; Min 15-17 deg C) that cause weak dispersion of pollutants. Cloudy sky and intermittent drizzle are likely that leads to low ‘Mixing layer height’ during daytime (< 1.0 km) resulting in weak vertical mixing.”

It said local weather conditions were expected to reduce the dispersion of pollutants. “Strong upper-level winds from [the] northwest direction are likely on 11th [Friday] and 12th [Saturday] enhancing [the] inflow of pollutants if fire counts increase that may deteriorate AQI to [the] upper end of very poor.”

The minimum temperature on Thursday is likely to be 16 degrees Celsius and the maximum of 30 degrees Celsius.