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After week of bad air, Noida takes a deep breath as winds pick up
Noida: After reeling under alarmingly hazardous air quality for seven days, Noida on Tuesday had some reason to sigh as the smog and pollutants dispersed substantially,
Noida: After reeling under alarmingly hazardous air quality for seven days, Noida on Tuesday had some reason to sigh as the smog and pollutants dispersed substantially, with the result that the air quality index (AQI) of Noida and adjoining regions climbed down from ‘severe’ levels to ‘very poor’.
The improvement is attributed to meteorological conditions, but pollution analysts warned that the air quality may deteriorate again, given the increase in farm fires in neighbouring Punjab and Haryana.
According to Central Pollution Control Board (CPCB), the AQI of Noida on Tuesday, on a scale of 0 to 500 with being the least polluted and 500 the most severe, was 351 or ‘very poor’, against 430 or ‘severe’ a day earlier.
The AQI of Noida, Greater Noida and Ghaziabad has been in the ‘severe’ category since last Tuesday (October 29).
The air quality improved even as the number of farm fires in Punjab and Haryana increased to 4,962 a day on Monday (November 4) from 2,500-3,000 on Sunday due to strong surface winds, System of Air Quality and Weather Forecasting And Research (Safar) said.
The major pollutant, particulate matter (PM)2.5, was still above the safe limit in Noida and it ranged from 230.01 to 281.99μg/m3, about three to four times the national safe limit of 60μg/m3, and nine to 11 times the international limit of 25μg/m3.
On Monday night, surface winds picked up from 5-6kmph (during daytime) to 10-15kmph, which by Tuesday 2.30pm increased to 25-30kmph in the westerly direction.
The wind direction, however, changed by Tuesday 5.30pm to west- southwest and the speed dropped to 4kmph, India Meteorological Department (IMD) said. However, Tuesday’s winds were strong enough to flush out the pollutants and the drop in humidity levels also helped.
“The wind speed at 2.30pm was 25kmph and by 3.30pm, it was 30kmph. The visibility was better, too, and the humidity dropped from 94% to 43% on Monday and from 81% to 36% on Tuesday,” an official from the IMD said.
Higher humidity levels are not conducive for improvement in air quality as pollutants get trapped in the atmosphere. However, analysts pointed out that the reason for the improvement is purely meteorological and that the air quality is still ‘very poor’, which is just as harmful to health and not a reason to rejoice.
“As the wind speed increased, the smog dissolved and the heat increased. Due to this, the air at the surface also warmed up and drifted upwards, thereby killing the inversion layer. The lighter the air, the easier it is for winds to flush out the dust and smoke. This is purely temporary and the pollution situation would have continued to be severe had the wind speed not increased,” Mahesh Palawat, director, private weather forecasting group, Skymet, said.
According to weather analysts, the air quality is likely to improve further due to the possibility of rain on November 7, owing to a western disturbance and Cyclone Maha reaching the Gujarat coast.
“The air in the region is still unhealthy and the improvement is purely due to weather conditions. However, additional measures taken by Environment Pollution(Prevention and Control) Authority have also helped in stopping the air quality from slumping again,” Shambhavi Shukla, programme manager, clean air, Centre for Science and Environment, said.
