With the winter season in India reaching its peak, many states remain covered in the dense cloak of fog. While for some fog brings an opportunity to stay at home and sit in the bonfire, it turns deadly for vehicles running in the night. In the past 1 month, India has registered multiple accident cases all because of low visibility done to dense or very dense fog. Not only this, many lives have also been lost due to low visibility. The danger of fog is such that it does not affect only one vehicle but a series of vehicles all at once. For instance, in November, at least 30 vehicles collided all at once on the Khanna-Ludhiana Highway resulting in 1 death and multiple injuries. Late arrival of trains and cancellation of flights are the two other problems that fog gives birth to especially in states like Punjab, Uttar Pradesh, New Delhi, Bihar, etc. True Scoop News brings you a detailed analysis on what is fog, why it forms, and why some Indian states are more prone to it-
If described in what is being seen, fog looks just like smoke spreading in the atmosphere. However, fog is totally different from smoke or smog. Fog is a visible aerosol consisting of tiny water droplets or ice crystals suspended in the air at or near the Earth's surface. Hence, fog is also called a 'grounded cloud'. There are three major factors that contribute to fog formation causes- the presence of moisture in the atmosphere, low temperatures, and still winds.
Notably, there are different types of fog depending on the visibility. Dense fog visibility is between 50 metres and 200 metres, and very dense when it is less than 50 meters. In general, fog develops after the sun sets. However, there are times when even sunrays struggle to pierce its layers. States like Punjab and Haryana often witness dense to very dense fog even during the daytime.
As mentioned earlier the three factors contributing to the formation of fog, generally start to form in the month of October in many states. The reason is India and its subcontinents enter into the winter season staring in October. Therefore, till the month of February, the condition for fog formation remains conducive. During these months, the sun normally shines bright during the day but temperatures dip after it goes down.
Talking about the scientific reason- the sun evaporates water from morning dew, lakes and rivers producing invisible water vapour. When the temperatures drop and the air cools quickly, the water vapour turns back into droplets that gather atmospheric dust/particles, creating fog that is visible.
Are some Indian states more prone to fog?
The answer is yes. As discussed above, fog forms in a stable air mass environment, and states like Punjab, Haryana, UP, Bihar, and New Delhi i.e. North India have most of the time a stable mass environment. The larger the temperature changes, the denser the fog. Places that are not much densely populated or scarcely populated, it witness a very dense fog. Hence, this is the reason why one needs to be careful while driving on highways at this time of the year.