A veil of haze hung over most of the city throughout Sunday as Delhi continued to receive a heavy load of pollutants from the agricultural fires that ravaged neighboring Punjab and Haryana, turning the city’s air into a toxic cocktail of particles. ultrafine microscopic and gaseous emissions.
For the fourth day in a row on Sunday, Delhi’s Air Quality Index (AQI) was in the severe zone with a value of 416, indicating a health hazard for all those who were exposed to such poor air. Crop stubble fires in northern states contributed 29% of Delhi’s PM 2.5 load according to estimates from the Air Quality System and Weather Forecasting and Research, Indian Institute of Tropical Meteorology.
PM 2.5 concentrations reached 250 micrograms per cubic meter on Sunday, more than four times the national ambient air quality standards and 25 times the World Health Organization-prescribed limit of 10 micrograms per cubic meter.
There were more than 4,900 fire points in Punjab on Saturday and more than 3,500 on Sunday, according to data from the Ministry of Earth Sciences (MoES). The combination of smoke from the crop fires and calm winds led to a significant deterioration in air quality. Farmer leaders said the crop fires are likely to continue until November 15, when the harvest will be completed. One of the reasons for the prolonged period of stubble fires in Punjab is the shortage of agricultural labor that had moved to their states during the national shutdown due to the Covid 19 pandemic.
“The fires will continue for a week or so. All the late varieties of rice are now being harvested. Many parts of the state faced labor shortages this year. Most of the agricultural work comes from Bihar and UP. They traveled back home during the confinement. There was a labor shortage during the beginning of the harvest season, ”said Harinder Singh Lakhowal, general secretary of Bharatiya Kisan Union. Agra, Bhiwadi, Baghpat, Bulandshahr, Faridabad, Ghaziabad, Gurugram and many other parts of northwestern India also saw “severe” air on Sunday.
The scientists said air quality is unlikely to improve in the next two days. “In the morning the conditions were hazy but, during the day, the relative humidity is below 75%, so what we are seeing is just smoke and pollution. The winds are calm so the dispersion of pollutants is not possible. Visibility this afternoon is only 600 meters when normally during this season it should be at least 2,000 meters in the afternoon hours. No chance of improvement until Diwali. At the most, the wind speed can increase from 8 to 10 km / h, “said Kuldeep Shrivastava, director of the regional weather forecast center.
A western disturbance is likely to affect the northwest region around Diwali day on November 14, but that may not contribute much to the spread of pollutants. “In fact, the wind direction will change to the east briefly on November 11 or 12, when the wind speed will decrease, causing the accumulation of pollutants. The western disturbance is likely to only bring rain and snow to the upper reaches of the mountainous states, not to the northwestern plains, ”Shrivastava added.
“Currently there is anticyclonic wind circulation at the lower levels and subsidence (downward settlement) of the air in large parts of northwestern India. Both are related to slow winds and accumulation of pollutants. We have seen a lot of crop stubble fire points. The combination of these factors is leading the air quality index (AQI) to oscillate between very poor and severe categories over the past four days, ”explained RK Jenamani, senior scientist at the National Weather Forecast Center. “The center of the anticyclonic wind circulation is just south of Delhi today, which makes most of the impact felt here,” he added.
According to the Royal Meteorological Society, under an anticyclone, the air descends forming an area of greater pressure on the surface. Due to these stable conditions, cloud formation is inhibited, so the climate generally stabilizes with only small amounts of cloud cover. This very stable atmosphere leads to the accumulation of pollutants, experts said.
“The winds are in a transition phase. On Monday night, they may change to the northeast direction, but there is no probability that the air quality will improve because the wind speed is likely to be very low. Air quality may also remain severe on Monday and we don’t expect any significant improvement on Diwali either. The fire counts are extremely high, the adverse weather is leading the AQI to rise to a severe category, ”said Vijay Soni, Scientist, IMD, Air Quality Division.
The ventilation index was only approx. 6000 m2 / s on Sunday. The ventilation index is a function of the mixing height and the wind speed and defines the capacity of the atmosphere to disperse pollutants. A ventilation rate below 2,350 square meters / second is considered poor. Mixing height is the height at which the pollutants in the air mix.
Commission yet to be met
Although the six full-time members of the Air Quality Management Commission for the National Capital Region (NCR) took over on Friday, days after the Center issued an ordinance on October 29 to establish the new centralized agency with broad powers to monitor and act against air pollution, the members have yet to meet. The rules for the operation of the commission are also to be defined.
“The meeting of the members of the commission does not depend on the elaboration of rules. The rules for the operation of the commission will be framed in due course. The commission will meet next week and begin its work, ”said Ravi Agrawal, special secretary of the Ministry of the Environment.
MM Kutty, the commission’s chairman and former Delhi chief secretary, did not respond to calls on Sunday.
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