A thick layer of fog engulfs Nizamuddin space in New Delhi on a chilly winter day, January 3, 2024.
| Photo Credit: ANI
The story to this point: As winter tightened its grip on northern India, a thick blanket of fog descended on a number of states in the final days of 2023 and first of 2024, creating difficult situations for residents and travellers alike. Some locations in the nation’s north reported low temperatures and dense fog for the final week of December. According to climate studies in late December 2023, minimal temperatures in Punjab, Haryana, and the northern reaches of Rajasthan and Uttar Pradesh hovered round 6-9 levels C. In New Delhi, south Rajasthan, and north Madhya Pradesh, some locations recorded minimal temperatures in the vary of 10-12 levels C, in response to the India Meteorological Department (IMD).
In the identical time, most of North India additionally skilled a dense fog that diminished visibility in many areas to as little as 50 metres for a number of days. Haryana, together with Chandigarh, plus remoted pockets of Uttarakhand, Uttar Pradesh, Bihar, Rajasthan, and Madhya Pradesh reported fog with visibility diminished to beneath 200 metres.
Other states together with Jammu & Kashmir, Himachal Pradesh, Odisha, Chhattisgarh, Jharkhand, and Uttarakhand additionally reported fog for just a few hours in the morning, the IMD reported.
What results did the fog have?
The fog’s principal impact was on air journey: practically 450 flights had been delayed or cancelled on December 27 at Delhi’s Indira Gandhi International Airport as a dense layer of fog enveloped the town. On December 29 and 30, nearly 100 after which 80 flights, respectively, had been delayed from Delhi.
The arrival and departure of a number of Delhi-bound trains had been additionally delayed by poor visibility and dense fog on December 29. The Hindu reported on December 29 that no less than eight trains that had been presupposed to have reached the nationwide capital the earlier evening didn’t whereas just a few trains scheduled to succeed in on the morning of December 29 had been delayed by just a few hours.
Auto-rickshaw and taxi drivers throughout the metropolis additionally reported battling low visibility as foggy situations made it troublesome to drive on roads.
What is fog?
The fog that disrupted the lives of individuals in North India is a typical climate phenomenon. A fog is a group of small droplets of water produced when evaporated water has cooled down and condensed.
According to Madhavan Nair Rajeevan, former director of the IMD and present Vice-Chancellor of Atria University, “Fog is nothing but a thick cloud, but very close to the earth’s surface. For a thick fog to form, temperatures should be lower and abundant moisture should be available near the surface.”
Fog materialises each time there’s a temperature disparity between the bottom and the air. This occurs often throughout Indian winters: the fog is created when the temperature drops at evening and in the early morning, condenses on aerosols current in the environment.
High humidity, mixed with an ample presence of water vapour or moisture, encourages foggy situations.
The course of by which it cools performs a pivotal function in the formation of fog.
One major mechanism contributing to fog formation known as infrared cooling. It usually happens when the climate is transitioning from summer time to winter. In the summer time, the bottom absorbs radiation from the Sun, turns into hotter, and moistens the air passing over it.
When cooler climate kicks in, this mass of heat, moist air comes in contact with processes that cool it. The ‘collision’ prompts the water vapour in the air to condense quickly, giving rise to fog.
Another sort of fog, often called radiation fog, is prevalent and happens when an unseasonably heat day with excessive humidity is adopted by quickly dropping temperatures.
The particular sort of fog, its length, and its results are contingent on varied environmental situations. (For instance, there exists a singular sort of fog that encourages snow to soften sooner.)
Why is northern India liable to fogging?
“The entire Indo-Gangetic plains are prone to formation of fog during winter season, as all the conditions — low temperatures, low wind speed, moisture availability and plenty of aerosols — are present in this region,” Dr. Rajeevan wrote in an e mail to The Hindu.
“Moisture incursion into this region can happen once a Western Disturbance — a precipational pattern that brings rain to north India during winter months — moves across northern parts.
“Sometimes, moisture incursion can happen from the Arabian Sea also.”
