What Science Says: How does wildfire smoke change the color of the air?

The smoke from the forest fire in Canada has created havoc all over America. Earlier, the color of the air of New York City had changed, now apart from Washington DC, other cities are also coming under its grip. The haze created in the cities due to the smoke of this fire has greatly reduced the ability to see, the stench has also made it difficult for people to leave their homes. All this is not because of any ordinary urban pollution. But after all, how can a forest fire change the color of the air of a city. Let us know what science says in answer to this question (What does Science Say)?

unprecedented in the eastern US
Although the havoc of forest fire has been seen in Western America and Western Canada only for the last few years, but this is the first time that such a fire has started in Eastern Canada and Eastern America is scorching due to its effect. And cities like New York, Washington DC are counted among the most prominent cities of the world. Pollution is also more in big cities, but it does not change the color of the air of the city in such a way that it is being seen now.

role of smog
This type of abnormal pollution in the city is due to smog. The word smog is derived from the words scom meaning smoke and fog meaning fog. Be it forest fire or any industrial pollution, whenever the smoke meets the pollution of the city, then such chemical processes start taking place in the atmosphere of the city, due to which such chemicals start forming in the air, due to which the color of the air starts getting reddish.

what does normal air look like
Small particles present in the atmosphere such as nitrogen and oxygen work to spread the light coming from the sky, which is called Raylig scattering. Due to this process, light waves get scattered, in which blue color waves get scattered more and in general, the sky looks blue due to this reason. But there is a change in this process in certain circumstances.

Forest fire smoke contains large particles of soot, which help create smog conditions. (Representational photo: Wikimedia Commons)

Urban pollution and photochemical smog
Oxides of nitrogen are prominent in urban pollution, which is caused by fossil fuel vehicles. These oxides combine with large particles of smoke to form chains of special chemical reactions, due to which a special type of smog is formed, which is called photochemical smog. Nitrogen oxides, sunlight and volatile organic compounds contribute to its formation.

Read also: New York’s smog is giving bitter lesson, climate change is not bounded by borders

volatile organic matter
Generally, volatile organic matter is very less in urban pollution. That’s why such smog is rarely seen. Forest fire smoke This equation makes ideal conditions for the formation of photochemical smog by meeting the shortage of volatile organic substances. Along with the smoke of forest fire, there are particles of burnt ash in the air which are large in size. These are the volatile biological substances due to which there is a difference in the scattering of light waves.

This type of incident is being seen for the first time in the cities of New York and Washington. (Representational photo: Wikimedia Commons)

how red
Due to the large particles, which are called particulate matter because of their size and are chemically volatile organic substances, sunlight coming from the sky tends to be scattered more in and around the red waves and hence the color of the air. Yellow appears orange and red. This scattering is called Mie scattering or scattering which dominates the Rayleigh scattering.

Read also: What Science Says: Why Do Some Comets Appear Green?

This type of process is seen in the conditions of forest fires, heavy industrial pollution and volcanic eruptions. The most famous example of this is the famous London smog of the 1950s. Apart from London, smog has formed in Chicago of America due to industrial reasons. At the same time, Indonesian cities have seen such a process in their cities due to volcanic ash. The direction of the wind is very important for such conditions to occur. Normally, the moist air coming from the Atlantic in the eastern US does not allow such conditions to develop, but this time the wind is weak.

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Tags: Canada, Climate, Environment, Pollution, Research, USA