What type of a cloud is fog

Although all fog can creep along on little cat feet, many types of fog exist. The basic mechanism that causes fog is simply anything that can bring the relative humidity up to percent.

Usually, when the air cools to the dew point, fog will roll in. That cooling may occur during a clear, calm night. The accumulated heat of the day will radiate from the earth, and the temperature near the ground cools.

It could cool all the way down to the dew point. That type of fog is called radiation fog because it is brought about by radiational cooling? This type of fog frequently forms in valleys, because there the wind has the best chance of being light. If the wind is gusty, that type of fog will not form because the atmosphere remains mixed, and will not likely cool as easily to the dew point.

When mountains and cliffs in the clouds appear, Some sudden and violent showers are near. Another type of fog occurs when warm air is brought over a colder surface. The warm air will be cooled on contact with the colder surface, and as its temperature lowers to the dew point, fog will develop. This fog often appears during a winter thaw when warm air streams over a frozen or snow-covered surface.

Fog is often said to be a great snow-eater. But it doesn't come along and chomp away at the snow. The warm air, which contributes to the fog, melts the snow away. Fog that develops over the ocean and in coastal areas often forms in a similar way. Warm air streams over a colder ocean surface. As soon as the air is cooled to its dew point, fog will shroud the ocean surface and adjacent shores.

If the air is tropical with plenty of water vapor and a high dew point, it will not take much to cool it to its dew point. Of course, if the water is cold, that also helps. Early summer is a favorite time for coastal fog. This entire fog category is called advection fog because warm air is advected, or brought to, colder regions. So far, we have looked at clouds that can be found at specific levels of the atmosphere. There are others that can be found extending through all elevations.

These are the ones associated with strong upward atmospheric currents. These updrafts spread the moisture through a large column of the atmosphere, and the clouds appear to have a puffy, even tower-like structure. Convection plays a big role in delivering these updrafts.

In fact, these clouds are often called convective clouds. The rain that falls from them is frequently referred to as convective precipitation. Just like a boiling pot of water, the atmosphere can cook on a hot summer's day, causing these convective clouds to appear. The precipitation is often heavy, but not necessarily long-lasting.

As they say, "The sharper the rain, the shorter the shower. The basic cumulus clouds fall into this category. Sometimes these puffy clouds are limited in vertical development. They look innocent enough and take on different shapes. This process is called advection , a scientific name describing the movement of fluid. In the atmosphere, the fluid is wind. When the moist , warm air makes contact with the cooler surface air, water vapor condenses to create fog.

Advection fog shows up mostly in places where warm, tropical air meets cooler ocean water. The Pacific coast of the United States, from Washington to California, is often covered in advection fog. The cold California Current , which runs along the western coast of North America, is much cooler than the warm air along the coast.

Valley fog forms in mountain valleys, usually during winter. Valley fog develops when mountains prevent the dense air from escaping. The fog is trapped in the bowl of the valley. In , vapor condensed around particles of air pollution in the Meuse Valley, Belgium. More than 60 people died as a result of this deadly valley fog. Freezing fog happens when the liquid fog droplets freeze to solid surfaces. Mountaintops that are covered by clouds are often covered in freezing fog.

As the freezing fog lifts, the ground, the trees, and even objects like spider webs, are blanketed by a layer of frost. The white landscapes of freezing fog are common in places with cold, moist climates, such as Scandinavia or Antarctica.

Fog Catchers Many ancient cultures collected water from fog by placing large pots under trees and shrubs. As the water from fog collected on these objects, the pots collected the water. This method of water collection was effective, but not as effective as collecting rainwater or other liquid water.

Today, engineer s are working on more sophisticated ways to collect water from fog. As fog glides in, water droplets form around the thin screens and drip to the collection pools below.

In one day, a single screen can collect more than a hundred gallons of water. The village of Bellavista, Peru, relies on fog catchers. Bellavista is an area that has little access to liquid water—no rivers, lakes, or glaciers are nearby. Wells dry up quickly. Water for irrigation and human consumption is threatened.

Every year, however, huge fogs blow in from the Pacific Ocean. In , the community invested in a series of fog catchers outside of town. Now, the residents of Bellavista have enough water to irrigate trees and gardens, as well as provide for their own drinking and hygiene needs. Engineers warn that fog catchers will only work in small areas. Still, engineers and politicians are working on ways to make more powerful fog catchers that will perhaps reduce the need for people to rely so much on groundwater.

Pea Souper A "pea souper" is a type of fog that forms when water condenses around microscopic particles of coal. This fog is often a brownish-yellow color, leading to the name. Pea soupers are common in areas that burn coal for energy.

The London Fog of , which killed 12, people around the urban center of London, England, was a pea souper. The Great Fog led to legislation that regulated the coal industry and air pollution in the United Kingdom. The cold Labrador Current from the north and the warm Gulf Stream current from the east create prime conditions for thick fog to form almost every day. Gas molecules are in constant, random motion.

Fog forms when the air near the ground cools enough to turn its water vapor into liquid water or ice. There are many different types of fog, too. Ice fog forms when the air near the ground is cold enough to turn the water in fog into ice crystals. Ice fog forms only at extremely cold temperatures. Ice fog is common in parts of Alaska and Canada.

Another kind of fog is freezing fog. Sometimes it is cold enough, but the air does not have any particles. When it comes into contact with cold surfaces such as roads and sidewalks, it instantly forms a dangerous icy layer. The smoke provides particles for the water vapor to condense around. This combination of smoke and water vapor is a dangerous one. A super fog is so dense that you would not be able to see your own hand in front of your face. Superfogs create very hazardous driving conditions.

Fog and smoke from a brush fire combined to make a super fog, resulting in this massive car accident in Florida in