In graphics | NASA issues warning as farm fires return to Delhi, NCR

The National Capital Region (NCR) and Delhi see declining air quality as winter approaches.

This is because of crop residue or stubble burning in neighbouring states like Punjab and Haryana.

For the next four to five days, Delhi's air quality is expected to fluctuate between the "poor" and "very poor" categories, according to the Center's Air Quality Early Warning System.

The National Green Tribunal listed stubble burning in Punjab throughout the autumn as one of the "biggest contributors" to pollution in NCR, according to Times Now. However, there has been a notable decrease in stubble-burning incidents in Haryana. As per official data, the state has experienced a drop of approximately 36 per cent in farm fires this year.

More from Explainers

Hiren Jethva, Senior Research Scientist at Morgan State University NASA Goddard Space Flight Centre told NDTV, "I was surprised to see that the fires in Punjab and Haryana have been lowest. We have never seen such low farm fires trend. There could be two reasons - the burning season has been delayed for some reason. It seems rainfall was in excess in Haryana and Punjab this July and August, which destroyed some crops. I am a bit afraid the (burning) season has been delayed, and we haven't seen the big fires, likely to happen in the coming two weeks."

Utilising data shared by NASA, the National Aeronautics and Space Administration, which has been monitoring the situation for several years now, we examine the farm fire scenario in the northern region of India.

All creatives designed by Network18