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2007-03-21 01:25:10 · 11 answers · asked by Anonymous in Science & Mathematics Weather

11 answers

cotton candy

2007-03-21 06:49:08 · answer #1 · answered by Anonymous · 0 0

Clouds contain mainly water vapour and condesation nuclei.When the air is brought to dew point temperature,condensation occurs.During the condensation process, water vapour is converted into water droplets which attach itself to a condensation nuclei and remains suspended in the air.Many such water droplets form the cloud.The atmosphere usually has sufficient condensation nuclei which are tiny particles of salt,dust particles or droplets of sulphuric acid.
In fact, the above hygroscopic nucleus which absorbs the water vapour in the atmosphere, grows up,overcomes the curvature effect and remains in suspension as a droplet leading to cloud formation.

2007-03-21 10:48:33 · answer #2 · answered by Arasan 7 · 0 0

A cloud is a visible mass of condensed droplets or frozen crystals suspended in the atmosphere above the surface of the Earth or another planetary body. The branch of meteorology in which clouds are studied is nephology.

On Earth the condensing substance is water vapor, which forms small droplets or ice crystals, typically 0.01 mm in diameter. When surrounded by billions of other droplets or crystals they become visible as clouds. Dense deep clouds exhibit a high reflectance (70% to 95%) throughout the visible range of wavelengths: they thus appear white, at least from the top. Cloud droplets tend to scatter light efficiently, so that the intensity of the solar radiation decreases with depth into the cloud, hence the grey or even sometimes dark appearance of the clouds at their base. Thin clouds may appear to have acquired the color of their environment or background, and clouds illuminated by non-white light, such as during sunrise or sunset, may be colored accordingly. In the near-infrared range, however, clouds would appear darker because the water that constitutes the cloud droplets strongly absorbs solar radiation at those wavelengths.

Clouds form when the invisible water vapour in the air condenses into visible water droplets or ice crystals. This can happen in three ways:

1. The air is cooled below its saturation point. This happens when the air comes in contact with a cold surface or a surface that is cooling by radiation, or the air is cooled by adiabatic expansion (rising). This can happen:

along warm and cold fronts
where air flows up the side of a mountain and cools as it rises higher into the atmosphere (orographic lift)
by the convection caused by the warming of a surface by insolation (diurnal heating)
when warm air blows over a colder surface such as a cool body of water.
2. Clouds can be formed when two air masses below saturation point mix. Examples are, our breath on a cold day, aircraft contrails and Arctic sea smoke.

3. The air stays the same temperature but absorbs more water vapor into it until it reaches saturation point.

The water in a typical cloud can have a mass of up to several million tonnes. However, the volume of a cloud is correspondingly high, and the net density of the relatively warm air holding the droplets is low enough that air currents below and within the cloud are capable of keeping it suspended. As well, conditions inside a cloud are not static: water droplets are constantly forming and re-evaporating. A typical cloud droplet has a radius on the order of 1 x 10-5 m and a terminal velocity of about 1-2 cm/s. This gives these droplets plenty of time to re-evaporate as they fall into the warmer air beneath the cloud.


Cumulonimbus cloudMost water droplets are formed when water vapor condenses around a condensation nucleus, a tiny particle of smoke, dust, ash, or salt. In supersaturated conditions, water droplets may act as condensation nuclei.

2007-03-21 08:33:52 · answer #3 · answered by Vlado 4 · 0 2

Condensed water. When water rises it condenses and gathers to form clouds.

2007-03-21 08:33:06 · answer #4 · answered by seminole0885 3 · 1 0

Water vapour!

2007-03-21 10:43:38 · answer #5 · answered by Nay 5 · 0 0

same stuff that makes fog. little water droplets that have come together to make them big enough to see. fog is pretty much the samething.

2007-03-21 10:16:20 · answer #6 · answered by Homer 4 · 0 0

water vapour

white cotton candy

2007-03-21 08:34:43 · answer #7 · answered by Anonymous · 1 0

answer in short- water

2007-03-24 20:20:35 · answer #8 · answered by absolutebalderdash1 2 · 0 0

condensed water.... n ice

2007-03-21 08:58:52 · answer #9 · answered by Gem-in-i 2 · 0 0

A cloud is a visible mass of condensed droplets or frozen crystals suspended in the atmosphere above the surface of the Earth or another planetary body. The branch of meteorology in which clouds are studied is nephology.

On Earth the condensing substance is water vapor, which forms small droplets or ice crystals, typically 0.01 mm in diameter. When surrounded by billions of other droplets or crystals they become visible as clouds. Dense deep clouds exhibit a high reflectance (70% to 95%) throughout the visible range of wavelengths: they thus appear white, at least from the top. Cloud droplets tend to scatter light efficiently, so that the intensity of the solar radiation decreases with depth into the cloud, hence the grey or even sometimes dark appearance of the clouds at their base. Thin clouds may appear to have acquired the color of their environment or background, and clouds illuminated by non-white light, such as during sunrise or sunset, may be colored accordingly. In the near-infrared range, however, clouds would appear darker because the water that constitutes the cloud droplets strongly absorbs solar radiation at those wavelengths.

Cloud formation and properties
Clouds form when the invisible water vapour in the air condenses into visible water droplets or ice crystals. This can happen in three ways:

1. The air is cooled below its saturation point. This happens when the air comes in contact with a cold surface or a surface that is cooling by radiation, or the air is cooled by adiabatic expansion (rising). This can happen:

along warm and cold fronts (frontal lift)
where air flows up the side of a mountain and cools as it rises higher into the atmosphere (orographic lift)
by the convection caused by the warming of a surface by insolation (diurnal heating)
when warm air blows over a colder surface such as a cool body of water.
2. Clouds can be formed when two air masses below saturation point mix. Examples are, our breath on a cold day, aircraft contrails and Arctic sea smoke.

3. The air stays the same temperature but absorbs more water vapor into it until it reaches saturation point.

The water in a typical cloud can have a mass of up to several million tonnes. However, the volume of a cloud is correspondingly high, and the net density of the relatively warm air holding the droplets is low enough that air currents below and within the cloud are capable of keeping it suspended. As well, conditions inside a cloud are not static: water droplets are constantly forming and re-evaporating. A typical cloud droplet has a radius on the order of 1 x 10-5 m and a terminal velocity of about 1-2 cm/s. This gives these droplets plenty of time to re-evaporate as they fall into the warmer air beneath the cloud.

Most water droplets are formed when water vapor condenses around a condensation nucleus, a tiny particle of smoke, dust, ash, or salt. In supersaturated conditions, water droplets may act as condensation nuclei.

The growth of water droplets around these nuclei in supersaturated conditions is given by the Mason equation.

Water droplets large enough to fall to the ground are produced in two ways. The most important means is through the Bergeron Process, theorized by Tor Bergeron, in which supercooled water droplets and ice crystals in a cloud interact to produce the rapid growth of ice crystals; these crystals precipitate from the cloud and melt as they fall. This process typically takes place in clouds with tops cooler than -15°C. The second most important process is the collision and wake capture process, occurring in clouds with warmer tops, in which the collision of rising and falling water droplets produces larger and larger droplets, which are eventually heavy enough to overcome air currents in the cloud and the updraft beneath it and fall as rain. As a droplet falls through the smaller droplets which surround it, it produces a "wake" which draws some of the smaller droplets into collisions, perpetuating the process. This method of raindrop production is the primary mechanism in low stratiform clouds and small cumulus clouds in trade winds and tropical regions and produces raindrops of several millimeters diameter.

The actual form of cloud created depends on the strength of the uplift and on air stability. In unstable conditions convection dominates, creating vertically developed clouds. Stable air produces horizontally homogeneous clouds. Frontal uplift creates various cloud forms depending on the composition of the front (ana-type or kata-type warm or cold front). Orographic uplift also creates variable cloud forms depending on air stability, although cap cloud and wave clouds are specific to orographic clouds.

"Hot Ice" and "Ice Memory" in cloud formation
In addition to being the colloquial term sometimes used to describe dry ice, hot ice is the name given to a surprising phenomenon in which water can be turned into ice at room temperature by supplying an electric field of the order of 1 million volts per meter. (Choi 2005). The effect of such electric fields has been suggested as an explanation of cloud formation. This theory, however, is highly controversial and is not, by any means, widely accepted as being the actual mechanism of cloud formation. The first time cloud ice forms around a clay particle, it requires a temperature of -10°C, but subsequent freezing around the same clay particle requires a temperature of just -5°C, suggesting some kind of "ice memory"

2007-03-21 08:32:48 · answer #10 · answered by catzpaw 6 · 0 4

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