About 25 per cent of the population in India is experiencing dense fog, with visibility dropping to less than 50 metres for the fourth consecutive day. In Punjab, Haryana, Madhya Pradesh, Rajasthan, and Uttar Pradesh, visibility ranged from 50 to 25 metres. Satellite imagery reveals the presence of fog in the north India region.
According to the India Meteorological Department (IMD), dense fog is expected over Delhi, Uttar Pradesh, Haryana, and Punjab until January 1, 2024. A total of 134 flights and 22 trains were delayed, with visibility dropping to as low as 50 metres in some parts of Delhi. Passengers were seen queuing up at the gates of the Indira Gandhi International Airport and railway stations amid intense fog.
The Gautam Buddh Nagar administration on Thursday ordered the closure of all schools across Noida and Greater Noida on Friday and Saturday due to cold weather conditions.
This is a yearly ritual of sorts when air and rail traffic is severely affected for days as fog engulfs the northern part of the country, and near-zero visibility disrupts the operations of trains and flights, despite the myriad old as well as new technology being used to minimise the impact.”
At 5:30 am, IMD reported that visibility at Delhi’s Safdarjung Observatory dropped to 50 metres, while Palam, near Delhi airport, recorded a visibility of 25 metres. In Punjab, Haryana, Madhya Pradesh, and Uttar Pradesh, visibility ranged from 50 to 25 metres.
The IMD had issued an ‘orange’ alert, forecasting ‘dense’ to ‘very dense’ fog. It also predicted cold day conditions in isolated parts of Delhi. The minimum temperature in Delhi stood at 8.4 degrees Celsius on Thursday morning, two degrees above normal, compared to 7.8 degrees Celsius a day earlier.
Delhi airport reported delays in flight operations, affecting approximately 134 flights, including both arrivals and departures (domestic and international), due to fog. Among them, 35 international flight departures and 28 international arrivals were delayed. Additionally, 43 domestic departures and 28 domestic arrivals faced delays. The airport classifies a flight as ‘delayed’ when it is late by more than 15 minutes.
“The four-airstrip Indira Gandhi International (IGI) Airport currently has only one CAT-III runway, allowing planes to land during very low visibility. The main runway, 28/10, is currently closed for repairs. Due to insufficient low-visibility operation-trained crew rostered by airlines and the closure of the main runway, delays and diversions have become common at Delhi, India’s busiest aviation hub, especially on days with dense fog. Once an aircraft is delayed, other flights scheduled across the airline’s network for that day may also face delays or cancellations. Other contributing factors include fog at other airports, airlines not deploying the right planes and crew for low-visibility landings, and typical engineering issues.
The problem lacks an easy fix, as the location makes North India, particularly Delhi, susceptible to fog. As winter arrives, the ground cools rapidly at night, especially over the Indo-Gangetic Plain, causing the air close to the ground to cool down as well. Since cold air can hold less moisture, the water vapor present condenses into tiny water droplets, forming fog.
A Northern Railways spokesperson mentioned that at least 22 trains were delayed by more than one hour on Thursday morning. This included the Puri-New Delhi Purushottam Express, which was running late by more than six hours.
“In winters during dense fog, trains are run at reduced speeds to avoid any mishaps,” the spokesperson explained.
Meanwhile, Delhi’s air continued to remain ‘very poor’ on Thursday, showing marginal improvement in the past 24 hours. The average air quality index (AQI) was 377 (very poor) at 9 am, settling at 358 at 4 pm. Forecasts indicate that Delhi’s air quality is likely to remain ‘very poor’ till December 30. In the Anand Vihar area, PM2.5 levels remained in the ‘severe’ category at 500, while PM10 reached 495. CO plummeted to 108, classified as ‘moderate,’ according to the Central Pollution Control Board (CPCB). The Bawana station recorded alarming PM2.5 at 450 and PM10 at 398, falling into the ‘severe’ and ‘very poor’ categories, respectively. Although CO levels were marked ‘satisfactory’ at 98. The Indira Gandhi International (IGI) Airport T3 witnessed PM2.5 levels at 411 and PM10 at 323, both again falling under the ‘severe’ and ‘very poor’ categories. The CO level was recorded at 111, maintaining a ‘moderate’ rating. ITO’s monitoring station reported PM2.5 at 500, categorised as ‘severe,’ while PM10 touched 458. CO levels were ‘moderate’ at 127, with NO2 at 49, falling into the ‘good’ category. At the New Moti Bagh station, the air quality was ‘severe,’ with PM2.5 at 465.
The IMD also mentioned that ‘Cold Day’ conditions are very likely in some parts of Punjab, Haryana, Chandigarh, Delhi, and West Uttar Pradesh and in isolated pockets over East Uttar Pradesh on Friday.
IMD, however, stated that the city is unlikely to witness a cold wave in the remaining days of the month, and the minimum temperature is expected to stay around 6 to 8 degrees Celsius until December 31. “Under the influence of a fresh Western Disturbance, light rainfall/snowfall is very likely over Jammu & Kashmir, Ladakh, Gilgit, Baltistan, Muzaffarabad, Himachal Pradesh, and Uttarakhand on Saturday and Sunday,” said the IMD.”
