Environmental experts have confirmed that the smog that enveloped Kochi skies on Tuesday and Wednesday was radiation fog.
The unprecedented formation of thick misty fog has been a hot topic of discussion in Kochi after morning joggers had complained of suffocation.
The issue was discussed threadbare on social media.
“Folk, #KochiFog is dry. Construction dust and smoke responsible?” read a tweet.
“Is it an onset of fire in some factory in the outskirts?” asked another tweeter.
What is radiation fog?
Formation of radiation fog occurs when the lower atmosphere, including the air that is closer to the ground, cools down overnight as part of a change in season.
Dr S Abhilash, Associate Director at the Centre of Atmospheric Sciences at Cochin University of Science and Technology, explained that drastic cooling of lower atmosphere was the cause of the smog.
“The north-east monsoon, which started on October 16, has caused a drastic cooling of lower atmosphere. This process is known as radiation cooling. The air which is close to the ground saturates following the rise in its relative humidity. This highly humid, saturated low-lying air is the fog we see these days,” he said.
Reason for the foul smell
The smog in Kochi had a foul smell. Dr Abhilash said pollutants, which usually ascend to the upper layers of atmosphere due to surface heating, stays in the lower atmospheric layer due to the sudden cooling. “Thus the smog becomes dense, hazy or blinding.”
How smog affects immunity
Many city residents have been seeking medical attention for suffocation, chest congestion, breathing problems and cold. Paediatrician Dr Nidhin V Mathew said suspended pollutants in the air have reduced children's' immunity. “Children are the first victims of atmospheric changes,” he said.
Expect more hazy mornings
Media reported, quoting experts, that climate changes caused the Kochi smog and it would continue for the next two months.
But, the sky was clear on Thursday. Reports suggested that previous night's heavy rain might have cleansed the lower atmosphere and stabilized the ground temperature.
But Abhilash said Kochi will witness more hazy mornings in November and Decembers. “Increasing construction and massive demolition activities will add up to the smog. It may not happen everyday, but the Kochi smog will not disappear very soon,” Abhilash said.
