Science Behind Fog

The Weather Channel

17 Oct 201301:10

Summary

TLDRFog is a cloud that forms at ground level, composed of tiny water droplets or ice particles suspended in the air. It forms when air cools to the dew point, becoming fully saturated with water vapor that condenses around particles like dust. Radiation fog, the most common type, occurs during autumn mornings with clear skies and cool temperatures, dissipating after sunrise as the ground warms. For weather ideas, join Weather Lab on Facebook or Twitter.

Takeaways

🌫️ Fog is a cloud that forms at ground level.
💧 Fog consists of tiny water droplets or ice particles suspended in the air.
🌡️ It forms when air cools to the dew point temperature and becomes fully saturated with water vapor.
🌌 The condensation occurs around microscopic particles like dust, forming water droplets.
🌅 Radiation fog is the most common type, often occurring during autumn mornings.
🌌 It is aided by clear skies and crisp temperatures, which cause the ground to cool overnight through thermal radiation.
🌤️ Radiation fog typically clears up after sunrise as the ground warms up and the air can hold more water vapor.
📉 As air cools, it loses its capacity to hold water, leading to condensation and fog formation.
🔍 The process of condensation is key to understanding how fog forms.
📢 Suggestions for weather lab topics are welcome on social media platforms like Facebook and Twitter.

Q & A

What is fog?
-Fog is a cloud that forms at ground level, consisting of tiny droplets of water suspended in the air. It can also consist of tiny particles of ice during very cold conditions.
How is fog formed?
-Fog forms when the air cools to the dew point temperature, becoming fully saturated with water vapor. This vapor condenses around microscopic particles like dust, forming water droplets that create fog.
What is the dew point temperature?
-The dew point temperature is the temperature at which air becomes fully saturated with water vapor and can no longer hold the moisture, leading to condensation.
What is radiation fog?
-Radiation fog is the most common type of fog, often occurring during autumn mornings. It is aided by clear skies and cool temperatures, and forms when the land cools overnight due to thermal radiation.
What causes thermal radiation?
-Thermal radiation is the process by which the Earth's surface cools off overnight, dropping the temperature at the surface to the dew point, which allows condensation and the formation of fog.
When does radiation fog typically dissipate?
-Radiation fog usually dissipates soon after sunrise when the ground quickly warms up.
How does clear sky contribute to the formation of fog?
-A clear sky allows for more efficient cooling of the Earth's surface at night, which can lead to the formation of radiation fog.
What other types of fog exist besides radiation fog?
-While the script primarily discusses radiation fog, other types of fog include advection fog, which forms when warm air moves over a cold surface, and upslope fog, which forms when air rises and cools on the side of a hill.
How can dust particles contribute to fog formation?
-Dust particles provide a surface for water vapor to condense upon, forming water droplets that contribute to the formation of fog.
What is the role of temperature in fog formation?
-Temperature plays a critical role in fog formation, as it must cool to the dew point for the air to become saturated and for condensation to occur.
How can one submit ideas for a weather lab?
-Ideas for a weather lab can be submitted by finding and contacting them on Facebook or Twitter.

Outlines

00:00

🌁 Understanding Fog Formation

This paragraph explains the concept of fog as a cloud that forms at ground level. It's composed of tiny water droplets or ice particles suspended in the air. The formation of fog is linked to the cooling of air to the dew point temperature, where it becomes fully saturated with water vapor. This vapor condenses around microscopic particles like dust, leading to the creation of water droplets. The most common type of fog is radiation fog, which occurs during autumn mornings, aided by clear skies and cool temperatures. It forms due to the cooling effect of thermal radiation overnight, which lowers the surface temperature to the dew point, allowing condensation. This type of fog typically clears up after sunrise as the ground warms up.

Mindmap

Keywords

💡fog

Fog is a natural phenomenon where tiny water droplets or ice crystals are suspended in the air at or near the Earth's surface. In the video, fog is described as a cloud that forms at ground level. It is a key subject as the video aims to explain how fog forms and the conditions that lead to its creation.

💡cloud

A cloud is a visible mass of water droplets or ice crystals suspended in the atmosphere. The script uses the term 'cloud' to draw a comparison with fog, explaining that fog is essentially a cloud that forms close to the ground rather than high in the sky.

💡water droplets

Water droplets are tiny particles of liquid water that make up fog. The video explains that fog is composed of these droplets, which form when water vapor in the air condenses around microscopic particles.

💡ice particles

Ice particles are solid forms of water that can also constitute fog, especially during very cold conditions. The video mentions that fog can consist of tiny ice particles, highlighting the variability of fog composition.

💡air cooling

Air cooling refers to the process by which the temperature of the air decreases. The video describes how as the air cools, it loses its capacity to hold water, leading to condensation and the formation of fog.

💡dew point

The dew point is the temperature at which air becomes saturated with water vapor and can no longer hold all the moisture it contains. In the script, the dew point is crucial as it's the point at which the air becomes fully saturated, leading to condensation and fog formation.

💡saturated

To be saturated means to be completely filled or soaked with a substance. In relation to the video's theme, the air is said to be fully saturated with water vapor when it reaches the dew point, which is a precondition for fog formation.

💡condensation

Condensation is the process by which water vapor turns into liquid water. The video explains that when the air cools to the dew point temperature, water vapor condenses around microscopic particles to form water droplets, which are a component of fog.

💡microscopic particles

Microscopic particles, such as dust, serve as nuclei for condensation. The video mentions these particles as the centers around which water vapor condenses to form the droplets that constitute fog.

💡radiation fog

Radiation fog is a specific type of fog that typically forms during clear, calm nights when the ground loses heat rapidly. The video identifies radiation fog as the most common type, especially during autumn mornings, and explains how it forms due to the cooling effect of thermal radiation.

💡thermal radiation

Thermal radiation is the process by which heat is emitted from the Earth's surface. The video describes how thermal radiation causes the ground temperature to drop overnight, reaching the dew point and facilitating the formation of radiation fog.

💡dissipates

To dissipate means to gradually scatter or disappear. The video explains that radiation fog usually dissipates after sunrise as the ground warms up, illustrating the temporary nature of this type of fog.

Highlights

Fog is a cloud that forms at ground level.

Fog consists of tiny water droplets or ice particles suspended in the air.

Air cools and loses its ability to hold water, leading to condensation.

The dew point temperature is when air becomes fully saturated with water vapor.

Condensation occurs around microscopic particles like dust.

Radiation fog is common during autumn mornings.

Clear skies and cool temperatures aid in the formation of radiation fog.

Thermal radiation cools the land surface to the dew point, causing condensation.

Radiation fog typically dissipates after sunrise as the ground warms up.

The process of fog formation is explained by Mike Bettis in the Weather Lab.

Fog can also form from tiny ice particles during very cold conditions.

The dew point is critical for the formation of fog.

Fog forms when the air cools to the point where it can no longer hold water vapor.

Water vapor condenses into droplets around dust particles to form fog.

The cooling off of land overnight is known as thermal radiation.

Radiation fog is the most common type and is particularly prevalent in autumn.

Fog formation is a natural phenomenon explained by the interaction of air temperature and water vapor.

The Weather Lab explores ideas related to weather and invites audience participation.

Suggestions for the Weather Lab can be submitted via social media platforms.