Northern India is currently facing a severe air pollution crisis as seasonal fires and other pollutants continue to obscure the skies in the region. The air quality index in New Delhi reached a "very unhealthy" level, prompting schools to shut down and advisories to be issued for residents to minimize outdoor exposure.

According to Hiren Jethva, an aerosol scientist at Morgan State University and NASA, the smoke from the fires has spread all over to the Bay of Bengal. While the fire activity this year is not as intense as in previous years, the number of fires is still significant enough to contribute to the poor air quality in affected areas.

NASA satellite imagery has captured the thick plume of smoke pollution that has sprawled across northern India. The burning of paddy straw after rice harvest, known as stubble burning, is a common practice in northwestern India during November. This leads to the smoke spreading throughout the region, including New Delhi, which is home to nearly 35 million people.

The major contributors to the smoke pollution are the farm fires in the northwest, particularly in Punjab and Haryana, as stated by Jethva. Additionally, vehicle emissions, industrial activities, fires for heating and cooking, and dust from the Thar Desert add to the hazardous mix of pollutants in the air.

The impact of the pollution has forced the closure of schools in the region and even in Pakistan, which is also experiencing elevated air pollution levels. Local authorities have decided to dismiss schools and extend the upcoming winter break, while some have opted for virtual learning.

The timing of the burning season appears to be late this year as compared to previous years, potentially due to delayed monsoon rains and the subsequent delayed rice harvest. Jethva predicts that the burning season may last for another week or so, coinciding with the Hindu festival of Diwali, known for fireworks celebrations. This combination could further deteriorate the air quality, as observed in 2016, which was the worst burning season in the past two decades.

Efforts to mitigate the poor air quality in New Delhi include implementing the "odd-even" vehicle rule after Diwali, where only certain vehicles are allowed on the road on specific days to reduce emissions. Scientists are also planning to conduct cloud seeding experiments to induce rain and wash out some of the pollution in the city.

As per Jethva, it remains to be seen whether the smoke levels will peak and then subside in the coming weeks. However, he believes that eventually, the air quality will improve.