Delhi’s air quality returned to the ‘severe’ category on Tuesday, according to the SAFAR Forecast System, although the contribution of farm fires to PM2.5 levels has dropped to around 8%. According to NASA satellite data, the number of fires in Punjab this year is the highest since 2016 and recently exceeded the number of fires compared to last year.
According to data provided by Pawan Gupta, Senior Scientist of Earth Sciences at the University Space Research Association, NASA Marshall Space Flight Center, USA, the cumulative fire count for Punjab as of November 16 was 74,015, higher than the 72,373 recorded last year. Was. The data is from the Visible Infrared Imaging Radiometer Suite (VIIRS), an instrument aboard the Suomi National Polar-orbiting Partnership satellite.
Data from the same instrument indicates that the number of fires over the past six years has been the highest in 2016 when a count of 84,886 was recorded. After this, now this figure has been recorded this year. The number fell to 46,752 in 2017, 51,998 in 2018 and 40,528 in 2019, rising again to over 72,000 in 2020.
According to VIIRS data provided by Gupta, the number of fires in Haryana this year is 8,879. This is the highest since 2017 when the count of 9010 was recorded. Last year, the count for Haryana was 5,186, while the figure was 5,735 in 2019, and 7,501 in 2018. The highest figure so far is from 2016, when 12,286 counts were recorded. On the data, Gupta said, “The count of fires from the satellite is an indication of the number of satellite pixels detecting the fire. Each satellite fire pixel can represent one fire or several smaller fires, and so on, a large fire.” Multiple fires can be seen in satellite data. It depends on the resolution of the satellite, viewing geometry, the size and intensity of the fire.”
The Central Pollution Control Board’s daily AQI bulletin on Tuesday provided an AQI of 403 for Delhi, with PM2.5 and PM10 being the main polluters. It has worsened with the AQI of 353 on Monday.
However, the incidents of fire have come down in the last few days. On Tuesday, the ‘effective’ fire count from the travel forecast system fell to 1,820, from 3,125 on Monday and 3,445 on Sunday.
An update to the Safar system said on Tuesday that calm conditions and a low ventilation index are pushing the air quality into the ‘severe’ category. Ventilation index is usually determined by wind speed, humidity, temperature and the extent to which pollutants can rise and spread vertically. Gufran Baig, founding project director of SAFAR, said the wind speed and temperature have now reduced, trapping pollutants within Delhi.
The travel forecast for the next two days shows that there is no possibility of infiltration of pollutants due to stubble burning in the next two days as the wind direction will be from east of Delhi. But the air quality may remain between the upper end of the ‘severe’ and ‘very poor’ category till November 18.
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