[Biology Class Notes] on Difference Between Fog and Mist Pdf

Fog and mist are often confused with each other, but you need to understand the main differences between them. The fog is thicker than the mist, and are both composed of condensed water vapour clouds. Fog is denser than mist and thus has a greater effect on visibility, i.e. the former limits visibility to almost one kilometre, while the latter limits visibility to more than one kilometre. 

Understanding the effects of climate change is important for understanding why a particular climate situation occurs first. Both fog and mist are condensed water vapour clouds. In other words, water droplets on the surface of the earth in the atmosphere slightly limit visibility. In a similar configuration, there is a slight difference in density and to the extent that visibility between fog and mist is reduced. 

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Water droplets produce fog and mist, with the main difference being their overall location and density. A cloud that reaches ground level, even if that “ground” is a hill or a hilltop, is called fog. Temperature inversions, volcanic activity, and changes in humidity can all cause water droplets to suspend in the air, forming mist. 

Fog Definition

In simple words, fog is a term that is used to describe condensed water vapour that is suspended in the atmosphere, close to the surface of the earth, forming an opaque sheet that limits visibility. It is a dynamic atmospheric phenomenon that is greatly influenced by neighbouring bodies of water, wind speed, and topography.

Air can hold some amount of water. Air becomes more humid when there is more water and after a certain point it begins to cool down and, as the temperature reaches its dew point, it begins to condense and fog is formed.

Fog is a thick layer of cloud that forms at the lower surface of a water body such as a lake, moist ground, or the ocean. It occurs when the difference between the dew point and the air temperature is less than 2.5 degrees Celsius.

When gas liquefies into little water droplets suspended in the air, fog is formed. The junction of water vapour and air into upward-moving zones, midday heating or evaporating water off the surface of seas, or wetland are examples of this process. To generate clouds, water vapour must first liquefy on the surface of dust, salt, or ice. Drizzle or extremely light snowfall occurs as a result of fog. Drizzle occurs when the humidity reaches 100% and the small droplets become huge droplets.

Types of Fog

1. Radiation Fog

It is formed when the land cools after sunset, and this land then cools the surrounding air by thermal transmission. The temperature of the air is forced to decline and approach the dew point as a result of this transmission. As a result, fog is created.

2. Evaporating Fog

It is created by water bodies that are encased in a thick layer of chilly air. This arrangement has the potential to create a whirlpool on the water. This is also known as dust devil or steam fog.

3. Ice Fog

It is generated by the moisture in the air when a group of animals exhales at very low temperatures. It has something to do with the ground level, which is made up of microscopic ice crystals. This frequently occurs when the sky is clear.

4. Ground Fog

The fog that covers less than 60% of the sky is known as ground fog. The fog level does not extend to the higher clouds. This is similar to the radiation fog. In certain situations, the fog can reach tens of centimetres in thickness over some lands when winds are absent.

5. Freezing Fog

It is made up of super-cooled water droplets that freeze on the surface when they come into touch with it.

Mist Definition

Mist is an atmospheric phenomenon created at the surface of the earth by tiny water vapour suspended in the atmosphere, which in some way restricts visibility. This is caused by inversion of temperature, volcanic activity, and increases in humidity. The chemical cycle that transforms mist into the water globules is called dispersion.

Mist is a condition generated by the suspension of small water droplets in the air. It happens when warm, moist air is suddenly cooled. When air is exhaled in the winter or when throwing on a stove or sauna, it is usually visible.

If the humidity and temperature circumstances are appropriate, the spray can generate a mist. It also happens in the natural world when humid air comes into contact with a surface that is cooler than the air. It is most commonly witnessed when heated water droplets suddenly cool and become visible to us. Exhaling air in the cold or in a chilly environment is a common example.

Both sound similar, but there are some differences that differentiate both. Let’s learn the mist and fog difference to understand the meaning in detail.

Difference Between Fog and Mist

Impacts of Fog

Fog has the greatest impact on transportation, especially airport operations and highway travel, but it also has an impact on marine and rail transit. The consequences can range from aggravation due to delayed travel to fatal multi-vehicle highway collisions. The fog that is persistent and dense can cause planes to be grounded or severely slowed. 

Even with headlights, dense fog on roadways can restrict visibility to tens of feet, making travel risky. Drivers may perceive an object in front of them, such as a car, to be further away than it actually is, delaying their reaction time. Fog can influence depth perception as well.

Benefits of Fog

Fog has several environmental benefits that aren’t immediately apparent. Ferns, trees, and other plants have adapted to “collect” the minute water droplets in fog for their water demands in coastal places such as California’s sequoia forests. Fog “harvesting” is utilised in several regions of the world to collect water for home and agricultural usage. 

To catch the water droplets, large mesh nets are built. The water drips into a gutter at the bottom of the mesh frame, where it is routed to a storage tank via pipes. Fog harvesting is only possible in regions with appropriate winds, altitude, and frequency of fog, such as mountainous areas near coasts.

Safety in Fog

Fog is one of the most dangerous driving dangers you’ll ever come across. Follow these safety guidelines if you must drive in foggy weather. 

• Be slow.

• Be on the lookout! In a fog, visibility might shift suddenly.

• To provide adequate reaction time and stopping distance, increase the gap between your car and the car in front of you.

• All of your lights should be turned on. Use fog lights and low-beam headlights. High beams should not be used.

• Turn on your 4-way flashers if you’re driving slower than traffic to allow drivers arriving from behind a better chance to see and notice your vehicle. (Check your state’s laws on using flashers while driving).

• To improve visibility, use the windshield wipers and defroster as needed.

• Be prepared for unexpected stops from other vehicles. Vehicles may be closer than they appear at first.

• If at all feasible, drive in a “pocket” with no other vehicles.

• To regain control of your vehicle, turn off the cruise control.

• As a guide, use the right edge of the road or roadside reflectors.

• If you can’t see the traffic, listen to it.

• Unless it is absolutely required, do not change lanes or pass other vehicles.

• Keep in mind that other drivers are travelling in the same conditions as you, with the same visibility issues.

• If at all feasible, signal ahead of time and avoid abrupt brakes.

• Keep an eye out for parked and slow-moving automobiles.

Key Points

Fog: If cloud-like aggregated water droplets are seen within one kilometre, it is said to be fog.

Mist: If cloud-like aggregated water droplets are seen beyond one kilometre, it is said to be mist.

Mist is an atmospheric phenomenon caused by the floating of small amounts of vapour in the atmosphere or on the surface of the earth, causing visual problems. It is much lighter than the thick and dense fog. Fog is thicker than mist and lasts longer. Mist reduces vision to one to two kilometres, whereas fog reduces visibility to less than one kilometre (0.6 miles) (0.6 – 1.2 miles). Hence article is helpful for the readers to provide an idea about the difference between fog and mist.