Q:

What causes fog?

A:

Quick Answer

Water evaporating from a surface causes fog. Usually, this evaporation is from a body of water, such as a lake, river or the ocean, or it can be caused by water evaporating from moist ground in a yard or field.

Know More
What causes fog?
Credit: Ryan Vaarsi Flickr CC-BY-2.0

Full Answer

Water vapor is added to the air by the wind, by daytime heating and via precipitation. It can also come from plant transpiration, which is the reason that fog is often seen rising over a mountaintop. For fog to develop, the relative humidity needs to be near to 100 percent, and the dew point temperature and air temperature must be close to each other by around 4 degrees Fahrenheit.

Learn more about Earth Science

Related Questions

  • Q:

    What causes a monsoon?

    A:

    A monsoon is caused when a low-pressure area built up over a hot landmass reacts with a high-pressure zone over a cool ocean, sending moisture-laden wind toward the low-pressure zone. Once over the landmass, the ocean air rises and forms rain clouds. Dense cloud formation and heavy rains are especially likely to occur if there are higher elevations like with inland mountains.

    Full Answer >
    Filed Under:
  • Q:

    What causes landslides?

    A:

    Landslides can result from a variety of both natural and human causes. Factors that influence landslides include slope angle, climate, weathering, water content of the land, vegetation, geology and slope stability.

    Full Answer >
    Filed Under:
  • Q:

    What causes rainbows?

    A:

    A rainbow occurs when sunlight shines on water droplets, causing the light to bend. The light bends again when it bounces off the back of the droplet and exits. The bending of the light, called refraction, allows a person to view the different wavelengths of light.

    Full Answer >
    Filed Under:
  • Q:

    What causes geysers?

    A:

    Geysers occur when underground water deposits are heated by geothermal energy and build up pressure. When underground magma flows heat the reservoir above the boiling point, water is forced to the surface. Once the first splashes of water begin to erupt from the geyser, the entire body of water boils as the pressure decreases. This produces a massive spume of water and steam, emptying the reservoir.

    Full Answer >
    Filed Under:

Explore