AQI 58: Mumbai’s air quality best since November 3 last year

Data from the Central Pollution Control Board (CPCB) showed that of the 27 active stations on Saturday, the best air quality was recorded in Borivali East where the AQI touched 19, followed by 22 in Mulund. In fact, none of the AQI monitoring stations breached the 100 mark with nine of the 27 active stations registering AQI under 50 and 18 stations logging an AQI between 50-100.

For perspective, the CPCB regards AQI readings between 0 to 50 as good or safe, 51 to 100 as satisfactory, 101 to 200 as moderate, 201 to 300 as poor, 301 to 400 as very poor and above 400 as severe.

The change in AQI has also led to improved visibility and clear sky, marking a change from the haze-shrouded atmosphere.

Speaking to The Indian Express, senior scientists and experts attributed the sudden improvement in air quality to the influx of strong westerly winds from the ocean, which has led to the dispersal of suspended pollutants.

Gufran Beig, an atmospheric scientist and chair professor at National Institute of Advanced Studies (NIAS)-Indian Institute of Sciences (IISC), told The Indian Express, “Currently, the fast winds are coming from the ocean and blowing towards the land. The faster winds have led to dispersal of suspended dust particles, improving air quality. While generally there is a reversal in winds from day to night, the winds are consistent right now. The change in air quality will be felt across the western coast.”

According to Beig, the sudden wind rush from the seas is a result of the transition from the La Nina phenomenon to El Nino. “This is a period of transition where the La Nina is transitioning to El nino. With this transition, the colder water of the Pacific Ocean is changing to warmer water, which can play havoc on the winds. The change has caused an erratic situation which has led to faster wind speeds,” explained Beig.