Nasa in a statement on its website posted on Wednesday said: “When combined with smoke, such hotspots identify actively burning fires…Clustering of fires in this region is a common phenomenon each fall.”
The farmers in this region burn the waste from autumn or kharif crop while preparing land for plating the spring or rabi crop. “Farmers often use fire to return nutrients to the soil and to clear the ground of unwanted plants. While fire helps enhance crops and grass for pasture, the fires also produce smoke that degrades air quality,” Nasa said.
A Central Pollution Control Board (CPCB) official said low disbursal of pollutants because of weak westerly winds had prevented the smoke to disburse into the colder Himalayan region.
The particulate matter levels in most cities of the region was about three to four times of the national air quality standard on Tuesday morning, which further increased during the day with vehicular traffic increasing after a two-day Diwali break.
Agra in Uttar Pradesh saw the particulate matter level reaching about 360 micro grams in a cubic meter of air while it was 260 ug/m3 in Lucknow.
Based on inputs from the weather department, the CPCB believes the pollution levels in northern India will remain on a higher side for few days.