How does fog develop

A fog is just a cloud at the ground. Fog formation can occur in two ways. First, the air is cooled to the dew point which leads to the formation of fog droplets. When the air temperature is the same as the dew point temperature, condensation occurs on tiny particles floating in the air. The second method of fog formation requires water to evaporate from the surface into the air, raising the dew point until condensation occurs.

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. Also called radiation fog. Also called the Arctic Current. There has been a bridge on the site for more than 2, years. Also called ground fog. The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit.

The Rights Holder for media is the person or group credited. Fog invading downtown Louisville from the Ohio River. WHAS Freezing Fog Freezing fog occurs when water droplets remain in the liquid state until they come into contact with a surface upon which they can freeze.

Freezing fog in Jefferson Memorial Forest. Tony Bright Evaporation or Mixing Fog This type of fog forms when sufficient water vapor is added to the air by evaporation and the moist air mixes with cooler, relatively drier air. Hail Fog Hail fog is an unusual type of fog that forms shortly after a heavy hailstorm. Hail fog along Interstate 65 near Horse Cave, Kentucky. Weather Story. Weather Map. Follow us on Twitter.

Follow us on Facebook. Follow us on YouTube. Disclaimer Information Quality Help Glossary. Scott Taylor. Freezing fog is similar to radiation fog, but it occurs when the water vapor forms ice crystals instead of water droplets. In weather reports, we often hear that the fog will "burn off" by a certain time.

That terminology is actually a misnomer, however. Fog doesn't burn off, according to The Weather Channel. Instead, as solar energy — heat from the sun — heats up the ground near the edge of the fog, drier air enters the foggy area, causing the fog to evaporate. Ground fog usually first begins to evaporate at the edges, where it is thinnest.

Then the evaporation works inward, toward the center of the fog, where it is thickest. Some places, like San Francisco, are known for fog. The California city is noted for its foggy summers, with photos of the landmark Golden Gate Bridge shrouded in fog as a popular scene on postcards and framed art. So why is the city so foggy in the summer? Essentially, it's because air is moving from a colder place over the ocean to a warmer place over land, according to KQED, the public radio and television affiliate in San Francisco.

As the air moves, fog forms and then moves over land.