Smog blankets Malwa region
A spike in farm fire cases and bursting of crackers on Diwali, coupled with low wind speed and dip in temperature have led to the formation of photochemical smog in the region, according to the Department of Physics, Punjabi University, Patiala.
The Department of Climate Change and Agriculture Meteorology of the university has said that to disperse pollution, wind speed should be around six to nine km per hour (kmph). However, the maximum wind speed during October was around 4 kmph only on two occasions. During the entire remaining month, the maximum wind speed remained below 2 kmph.
Photochemical phenomenon
- Photochemical smog is produced when ultraviolet rays from the sun react with nitrogen oxide in the atmosphere
- It is visible as brown haze and is prominently visible in the morning and afternoon
- Earlier, this phenomenon was seen only in densely populated cities with high emission levels
- With stubble burning cases on the rise, the phenomenon is now also being witnessed in Malwa villages
“Such conditions do not allow change in night and day temperature. As a result, heat of the sun cannot penetrate into the earth’s surface, leading to relatively warmer evenings with particulate matter remaining high in the air, causing breathing discomfort,” said Dr Karamjit Singh Dhaliwal, Principal Investigator, ISRO-GBP ARFI Research Project, Assistant Professor, Department of Physics, Punjabi University.
“Moreover, biomass pollutants, dust, vehicular pollution and pollution caused due to bursting of crackers can also not disperse easily. This leads to a hazy atmosphere with sun rays not reaching the earth’s surface,” he added.
“At present, the average wind speed across the state is less than 2 kmph. Such conditions create a closed-room atmosphere where suspended particles remain locked in the atmosphere. During the summer season, the average air speed remains over 15 kmph, which is enough to disperse these particles,” said Pavneet Kaur Kingra, Head of the Department of Climate Change at PAU.
