Fast winds continue to blow pollutants away from Gurugram

Gurugram Air quality in the city continued to improve for the fourth consecutive day on Friday, with Gurugram recording a reading of 84 (‘satisfactory’) on the Central

Gurugram Air quality in the city continued to improve for the fourth consecutive day on Friday, with Gurugram recording a reading of 84 (‘satisfactory’) on the Central Pollution Control Board’s (CPCB) air quality index (AQI) bulletin at 4pm. This marks the re-entry of the air quality to the ‘satisfactory’ level since October 8, when the AQI reading was 78.

HT Image

The average daily concentration of finer particulate matter with a diameter smaller than 2.5 micrometres (PM2.5) on Friday was at 50ug/m3 (within the national safe limit of 60ug/m3). In fact, over the past three days, nitrous oxide (NO), a gaseous pollutant, has replaced PM2.5 the city’s most prominent pollutant, indicating the effective dispersal of particulate matter from the region.

Manesar, meanwhile, recorded its second consecutive day of ‘satisfactory’ air quality on Friday, with a reading of 76 on the AQI bulletin, down from 92 the previous day. Manesar, primarily an industrial township with typically higher levels of air pollution than Gurugram, was the least polluted NCR town on Friday. This, experts said, was due to a shift in wind direction.

“Earlier, westerly winds were blowing pollutants toward the capital. Now, the wind has changed direction and is blowing from the east. Usually, this results in an increase in pollution in Haryana’s NCR towns, but the winds are of sufficient speed to enable dispersal of PM2.5 and PM10,” a senior scientist at CPCB’s air quality lab in Delhi said.

Moreover, after two days of overcast weather, the city on Friday saw ample sunlight during the day, which, in turn, warmed up the atmosphere and allowed particulate matter to settle at greater mixing heights (i.e. further away from the surface of the earth), in addition to triggering stronger winds, explained Sachin Panwar, a city-based air quality scientist.

“Wind speeds on Saturday are also expected to remain strong, in the region of 15 to 20 kmph, so we should continue to see favourable air quality over the weekend,” he added.

The predicted AQI for Gurugram over the next three days is 114 (moderate) on Saturday, 137 on Sunday and 150 on Monday, according to the CPCB.

Penetration of sunlight also resulted in higher daytime temperatures on Friday. According to India Meteorological Department (IMD) data, the maximum daytime temperature recorded on Friday was 24 degrees Celsius, up from Thursday’s 22 degrees Celsius (which marked the coldest day in Gurugram so far). The minimum temperature, on the other hand, fell to 12.4 degrees Celsius early on Friday, from 16.5 degrees Celsius on Thursday.

According to IMD’s seven-day forecast, the minimum temperature is likely to touch 10 degrees Celsius on December 1, dipping to 9 degrees Celsius by December 5. The maximum temperature is expected to remain between 22 and 24 degrees Celsius till December 5.