Farm fires rage in Pakistan, no surge in Punjab – for now

Experts attributed the current spike to local factors and said the Pakistan fires have not yet contributed to Delhi’s pollution due to current wind patterns

Pakistan recorded 3,730 farm fires in the 10 days ending October 25, the highest count for that period in available records dating to 2012, raising alarm among meteorologists who warn the smoke plume will likely sweep across North India once wind patterns shift in the coming days.

The AQI in Delhi climbed to 292 (poor) at 4pm on Saturday, up from 275 a day earlier, marking a deterioration after a brief respite on Friday

The warning comes as Delhi’s air quality returned to “very poor” levels late on Saturday evening. The Air Quality Index (AQI) climbed to 292 (poor) at 4pm on Saturday, up from 275 a day earlier, marking a deterioration after a brief respite on Friday when stronger winds helped flush out Diwali firecracker pollution that had led to several days of 300-plus AQI. By 11pm on Saturday, the index had climbed back above 300 to settle at 310 (very poor).

Experts attributed the current spike to local factors and said the Pakistan fires have not yet contributed to Delhi’s pollution due to current wind patterns. Right now, winds are blowing from west to east, which has shifted most of the smoke to above Punjab and parts of Jammu and Kashmir.

But that is expected to change after a western disturbance passes through the region between October 27-29, a period when farm fires in Punjab too are predicted to surge.

“In the coming days, if stubble burning on the Punjab side of Pakistan continues, it actually might impact Delhi’s air pollution level as well,” said Madhavan Nair Rajeevan, former secretary of the ministry of Earth Sciences. “We are expecting northwesterlies in the coming days and depending on the wind speed, the particulate matters might be carried to the Capital and neighbouring areas as well. This might cause a spike in pollution level.”

Another meteorologist concurred. Ashwary Tiwari, who runs IndiaMetSky, said there is “a big possibility” the high farm fire count in Pakistan will impact air quality across the Indo-Gangetic Plain region once the Western Disturbance moves away.

“We are likely to see the impact of smoke and pollutants accumulating over the Pakistan-Sindh region and parts of adjacent northwestern India once the upcoming Western Disturbance moves away and northwesterly-westerly winds will set back over northern plains,” he said, adding that transport-level winds should be strong during this period.

Pakistan’s total October fire count through October 25 reached 5,908, the fourth-highest for that period in the past 13 years, according to NASA’s VIIRS satellite data. The fires have been heavily concentrated in the second half of October, with the 10-day period from October 16-25 recording the highest count since 2012, surpassing even 2021’s spike of 3,492 fires.

The spike in Pakistan fires stands in stark contrast to neighbouring Punjab, which is experiencing its lowest burning season on record, till now. Punjab recorded only 498 fires during the same 10-day period ending October 25, marking the lowest count since 2012. For comparison, 2016 saw 15,150 fires during the same period, while 2022 recorded 5,121 fires.

For the full October 1-25 period, Punjab has recorded just 661 fires compared to the 2012-2021 average of 11,877 fires.

However, only 52.28% of the 3.17 million hectares under paddy cultivation had been harvested by Saturday, according to the Punjab Pollution Control Board’s daily bulletin.

“With only a little more than half of the paddy crop harvested and the window for wheat sowing season reducing, the next few days will likely see a surge in burning as farmers rush to clear their fields within a limited time,” said a Punjab Pollution Control Board official, asking not to be named.

This means there will be more PM2.5 in the atmosphere over northwest India, which can sweep in over the Indo-Gangetic plains.

To be sure, this effect is likely to play out later in the coming week. For now, local weather conditions may play a more significant factor, as it did on Saturday. “While the wind speed has not shown any drastic change on Saturday, the direction of the wind has been a bit mixed throughout the day, due to which pollution from a lot of neighbouring areas like Gurugram, Ghaziabad, Sonipat and Gautam Buddha Nagar have accumulated in the Capital, leading to a slight spike in pollution level,” said Sunil Dahiya, founder and lead analyst at the think-tank Envirocatalysts.

The delayed harvest pattern mirrors last year’s season, which saw Punjab record 31,023 total fires for October-November. In 2023, there was an unusual spike in mid-November with fire counts reaching around 1,700 daily on November 14-16, a period that typically shows declining numbers.

Mahesh Palawat, vice president at Skymet Weather, explained that current meteorological conditions have prevented Pakistan fires from affecting Delhi. “Right now, the wind direction is west to east and wind speed is almost calm,” he said. “The contribution of stubble burning to pollution is highly dependent on meteorological conditions like wind direction and wind speed.”

Following the Western Disturbance, which Palawat said --- in what is similar to Tiwari’s and Rajeevan’s contention -- wind patterns will shift to northwesterlies, potentially carrying smoke from Pakistan toward Delhi and surrounding areas. He added the western disturbance is expected to bring clouding to the plains and light rain and snowfall to the hills

Tiwari warned that once the pollution arrives, “the effects should moderately be felt as AQI levels will spike. The pollution will marginally get better in the afternoon and spike during morning and night hours. Other effects will include a hazy-grey sky, due to smoke and soot hovering between 1,000 to 6,000 feet in the lower atmosphere, thus partially blocking sunshine.”

(With inputs from Aheli Das in Delhi and Karam Prakash in Patiala)