In recent days, a thick fog phenomenon has enveloped several northern and eastern states of India, severely impacting visibility.
According to Hindustan Times, zero visibility has been reported in some cities as dense fog persisted on January 14-15. This situation may last for the next 2-3 days.
The India Meteorological Department (IMD) issued warnings about this extreme weather condition, noting the occurrence of a cold wave in many states, with temperatures ranging between 3-7 degrees Celsius.
Dense fog in several northern states of India has disrupted the daily lives of residents. (Photo: Reuters).
According to Flightradar24, dense fog disrupted at least 463 flights departing from Delhi on January 15, and 500 flights were delayed the day before.
Additionally, daily life in areas affected by the fog has also been disrupted, with traffic halted and residents unable to go outside in the morning because they “couldn’t see anything.”
Meteorologists explain that the causes of dense fog include several factors: low wind, low temperatures, high humidity, and pollutants acting as condensation surfaces.
Thus, the presence of pollutants significantly exacerbates fog conditions.
Many previous studies have identified PM2.5 (particulate matter or aerosol particles with a diameter of less than 2.5 micrometers) as a major pollutant and a key contributor to smog and fog formation in the Indo-Gangetic Plain, including Delhi.
In 2021, a study from the Indian Institute of Technology Madras (IIT-M) found that the burning of plastic waste is a primary cause of smog and fog formation in northern India.
The study explains that complex chemical reactions involving hydrochloric acid (HCl), which are released directly into the atmosphere through plastic waste burning and some industrial processes, are the main contributors to high PM2.5 chloride levels.
This HCl then reacts with excess ammonia in the atmosphere to form ammonium chloride (NH4Cl) particles, leading to the development of smog and fog.
This weather pattern is more likely to occur during cold winter nights, as the cold air prevents pollutants from rising higher into the atmosphere, causing them to accumulate closer to the ground.
Moreover, slow wind conditions, low wind speeds, combined with high humidity typical of northern India also create ideal conditions for fog formation.
In fact, the phenomenon of dense fog has been present in India for several years, but it shows increasing severity due to a combination of climate change factors.
