Lost in the

When atmospheric water vapor condenses near the ground, it forms fog and mist. The fog consists of small droplets of water mixed with smoke and dust particles. Physically the fog is a cloud, but the difference between the two lies in their formation. A cloud develops when the air rises and cools, whereas fog forms when the air is in contact with the ground, which cools it and condenses the water vapor. The atmospheric phenomenon of fog decreases visibility to distances of less than 1 mile (1.6 km) and can affect ground, maritime, and air traffic. When the fog is light, it is called mist. In this case, visibility is reduced to 2 miles (3.2 km). •

160 feet

The densest fog affects visibility at this distance and has repercussions on car, boat, and airplane traffic. In many cases, visibility can be zero.

Fog and Visibility

Visibility is defined as a measure of an observer's ability to recognize objects at a distance through the atmosphere. It is expressed in miles and indicates the visual limit imposed by the presence of fog, mist, dust, smoke, or any type of artificial or natural precipitation in the atmosphere. The different degrees of fog density have various effects on maritime, land, and air traffic.

DENSE FOG

Means of transport are affected ^^^ by visibility. _

THICK FOG

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The condensation of water vapor on objects that have radiated enough heat to decrease their temperature below the dew point

Mist consists of salt and other dry particles imperceptible to the naked eye. When the concentration of these particles is very high, the clarity, color, texture, and form of objects we see are diminished.

Normal visibility

RADIATION FOG

This fog appears only on the ground and is caused by radiation cooling of the Earth's surface.

ADVECTION FOG

Formed when a mass of humid and cool air moves over a surface that is colder than the air

The air becomes saturated as it ascends.

Warm air

ASCENDING AIR

INVERSION FOG

When a current of warm, humid air flows over the cold water of an ocean or lake, an inversion fog can form. The warm air is cooled by the water, and its moisture condenses into droplets. The warm air traps the cooled air below it, near the surface. High coastal landmasses prevent this type of fog from penetrating very far inland.

Types of Fog

FRONTAL FOG

Formed ahead of a warm front

Radiation fog forms during cold nights when the land loses the heat that was absorbed during the day. Frontal fog forms when water that is falling has a higher temperature than the surrounding air; the drops of rain evaporate, and the air tends to become saturated. These fogs are thick and persistent. Advection fog occurs when humid, warm air flows over a surface so cold that it causes the water vapor from the air to condense.

FRONTAL FOG

Formed ahead of a warm front

Brief Flash

Electrical storms are produced in large cumulonimbus-type clouds, which typically bring heavy rains in addition to lightning and thunder. The storms form in areas of low pressure, where the air is warm and less dense than the surrounding atmosphere. Inside the cloud, an enormous electrical charge accumulates, which is then discharged with a zigzag flash between the cloud and the ground, between the cloud and the air, or between one cloud and another. This is how the flash of lightning is unleashed. Moreover, the heat that is released during the discharge generates an expansion and contraction of the air that is called thunder. •

THUNDER

This is the sound produced by the air when it expands very rapidly, generating shock waves as it is heated.

air air

Lightning originates within large cumulonimbus storm clouds. Lightning bolts can have negative or positive electric charges.

TYPES OF LIGHTNING f^M

Lightning can be distinguished primarily by the path taken by the electrical charges that cause them.

INSIDE THE CLOUD

Electrical charges are produced from the collisions between ice or hail crystals. Warm air currents rise, causing the charges in the cloud to shift.

SEPARATION

the charges become separated, with the positive charges accumulating at the top of the cloud and the negative charges at the base.

ELECTRICAL CHARGES

The cloud's negative charges are attracted to the positive charges of the ground. The difference in electrical potential between the two regions produces the discharge.

INDUCED CHARGE

the negative charge of the base of the cloud induces a positive charge in the ground below it.

DISCHARGE

The discharge takes place from the cloud toward the ground after the stepped leader, a channel of ionized air, extends down to the ground.

the electricity moves from the cloud toward an air mass of opposite charge.

Cloud-to-cloud

A lightning flash can occur within a cloud or between two oppositely charged areas.

Cloud-to-ground

Negative charges of the cloud are attracted by the positive charges of the ground.

the electricity moves from the cloud toward an air mass of opposite charge.

Cloud-to-cloud

A lightning flash can occur within a cloud or between two oppositely charged areas.

Cloud-to-ground

Negative charges of the cloud are attracted by the positive charges of the ground.

8,700 miles per second

(140,000 km/s) speed

LIGHTNING RODS

The primary function of lightning rods is to facilitate the electrostatic discharge, which follows the path of least electrical resistance.

Lightning bolt: 8,700 miles per second (140,000 km/s)

Airplane: 0.2 mile per second (0.3 km/s)

tip of the conductor lightning rod

□□□□□□ □□□□□□ □□□□□□

□□□□□□ □□□□□□ □□□□□□

100 million volts

IS THE ELECTRICAL POTENTIAL OF A LIGHTNING BOLT.

A windmill generates 200 volts.

) 110 volts is y consumed by j a lamp.

RETURN STROKE In the final phase, the discharge rises from the Earth to the cloud.

A lightning rod is an instrument whose purpose is to attract a lightning bolt and channel the electrical discharge to the ground so that it does no harm to buildings or people. A famous experiment by Benjamin Franklin led to the invention of this apparatus. During a lightning storm, he flew a kite into clouds, and it received a strong discharge. That marked the birth of the lightning rod, which consists of an iron rod placed on the highest point of the object to be protected and connected to the ground by a metallic, insulated conductor. The principle of all lightning rods, which terminate in one or more points, is to attract and conduct the lightning bolt to the ground.

POINT OF IMPACT

POINT OF IMPACT

This is the radius of a lightning bolt's effective range on the surface of the Earth.

"DISCHARGE SEQUENCE

channel 1st phase channel

1st return

2nd return 3rd return

the lightning bolt propagates through an ionized channel that branches out to reach the ground. Electrical charges run along the same channel in the opposite direction.

If the cloud has additional electrical charges, they are propagated to the ground through the channel of the first stroke and generate a second return stroke toward the cloud.

this discharge, as in the second stroke, does not have branches. When the return discharge ceases, the lightning flash sequence comes to an end.

Cold air

Cold air

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Renewable Energy 101

Renewable Energy 101

Renewable energy is energy that is generated from sunlight, rain, tides, geothermal heat and wind. These sources are naturally and constantly replenished, which is why they are deemed as renewable. The usage of renewable energy sources is very important when considering the sustainability of the existing energy usage of the world. While there is currently an abundance of non-renewable energy sources, such as nuclear fuels, these energy sources are depleting. In addition to being a non-renewable supply, the non-renewable energy sources release emissions into the air, which has an adverse effect on the environment.

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