Clouds

CloudsClouds

http://www.weatherwizkids.com/http://www.weatherwizkids.com/cloud.htmcloud.htm

What are clouds?What are clouds?

A cloud is a large A cloud is a large collection of very collection of very tiny droplets of tiny droplets of

water or ice water or ice crystals. The crystals. The

droplets are so droplets are so small and light that small and light that

they can float in they can float in the air.the air.


How are clouds formed?How are clouds formed?

• All air contains water, but near the ground All air contains water, but near the ground it is usually in the form of an invisible gas it is usually in the form of an invisible gas called water vapor. called water vapor.

• When warm air rises, it expands and cools. When warm air rises, it expands and cools. • Cool air can't hold as much water vapor as Cool air can't hold as much water vapor as

warm air, so some of the vapor condenses warm air, so some of the vapor condenses onto tiny pieces of dust that are floating in onto tiny pieces of dust that are floating in the air and forms a tiny droplet around the air and forms a tiny droplet around each dust particle. each dust particle.

• When billions of these droplets come When billions of these droplets come together they become a visible cloud. together they become a visible cloud.


Why are clouds white?Why are clouds white? • Clouds are white because they Clouds are white because they

reflect the light of the sun. reflect the light of the sun. • Light is made up of colors of the Light is made up of colors of the

rainbow and when you add them rainbow and when you add them all together you get white. all together you get white.

• The sun appears a yellow color The sun appears a yellow color because it sends out more yellow because it sends out more yellow light than any other color. light than any other color.

• Clouds reflect all the colors the Clouds reflect all the colors the exact same amount so they look exact same amount so they look white. white.


Why do clouds turn gray?Why do clouds turn gray?

• Clouds are made up of tiny Clouds are made up of tiny water droplets or ice water droplets or ice crystals, usually a mixture crystals, usually a mixture of both. The water and ice of both. The water and ice scatter all light, making scatter all light, making clouds appear white. clouds appear white.

• If the clouds get thick enough or high enough all If the clouds get thick enough or high enough all the light above does not make it through, hence the light above does not make it through, hence the gray or dark look. the gray or dark look.

• Also, if there are lots of other clouds around, their Also, if there are lots of other clouds around, their shadow can add to the gray or multicolored gray shadow can add to the gray or multicolored gray appearance. appearance.


Why do clouds float?Why do clouds float?

A cloud forms when air is heated by A cloud forms when air is heated by the sun. As it rises, it slowly cools until the sun. As it rises, it slowly cools until

it reaches the saturation point and it reaches the saturation point and water condenses, forming a cloud. water condenses, forming a cloud.

As long as the cloud and the air that it’s As long as the cloud and the air that it’s made of is warmer than the outside made of is warmer than the outside

air around it, it floats! air around it, it floats!


Cloud Groups and TypesCloud Groups and Types

• Cirrus (high clouds) – above 18,000 feetCirrus (high clouds) – above 18,000 feet– Cirrus, Cirrostratus, CirrocumulusCirrus, Cirrostratus, Cirrocumulus

• Alto (middle clouds) – 6,500 to 18,000 Alto (middle clouds) – 6,500 to 18,000 feetfeet– Altostratus, AltocumulusAltostratus, Altocumulus

• Stratus (low clouds) – up to 6,500 feetStratus (low clouds) – up to 6,500 feet– Stratus, Stratocumulus, NimbostratusStratus, Stratocumulus, Nimbostratus

oCumulus (low to high clouds)Cumulus (low to high clouds)

- Cumulonimbus- Cumulonimbus


CirrusCirrusHigh CloudsHigh Clouds


Cirrus CloudsCirrus Clouds • Cirrus cloudsCirrus clouds are the are the most common of themost common of the high clouds.high clouds. They are They are composed of icecomposed of ice and and are are thin, wispythin, wispy cloudsclouds blown in high winds into blown in high winds into long streamers. Cirrus long streamers. Cirrus clouds are clouds are usually whiteusually white and and predict fair to predict fair to pleasant weather.pleasant weather. By By watching the movement watching the movement of cirrus clouds you can of cirrus clouds you can tell from which direction tell from which direction weather is approaching. weather is approaching. When you see cirrus When you see cirrus clouds, it usually clouds, it usually indicates that aindicates that a change change in the weatherin the weather will will occur occur within 24 hours.within 24 hours.


Cirrostratus CloudsCirrostratus Clouds

• Cirrostratus cloudsCirrostratus clouds are are thin, sheetlikethin, sheetlike high high cloudsclouds that that often cover often cover the entire sky.the entire sky. They They are so thin that the are so thin that the sun and moon can be sun and moon can be seen through them. seen through them. Cirrostratus clouds Cirrostratus clouds usually come 12-24 usually come 12-24 hours before a rain or hours before a rain or snow storm. snow storm.


Cirrocumulus Cirrocumulus CloudsClouds• Cirrocumulus Cirrocumulus

cloudsclouds appear as appear as small, rounded small, rounded white puffswhite puffs that that appear appear in long rows.in long rows. The small ripples in The small ripples in the cirrocumulus the cirrocumulus clouds sometime clouds sometime resemble the scales resemble the scales of a fish. of a fish.

• Cirrocumulus clouds are Cirrocumulus clouds are usually seen in the usually seen in the winter winter and indicate and indicate fair, but cold weatherfair, but cold weather. In . In tropical regionstropical regions, they , they may indicatemay indicate an an approaching approaching hurricane.hurricane.


AltoAltoMiddle CloudsMiddle Clouds


AltostratusAltostratus Clouds Clouds

• Altostratus cloudsAltostratus clouds are are gray or blue-graygray or blue-gray mid level clouds mid level clouds composed of composed of ice ice crystals and water crystals and water droplets.droplets. The clouds The clouds usually usually covercover the the entire entire skysky. In the thinner . In the thinner areas of the clouds, the areas of the clouds, the sun may be dimly sun may be dimly visiblevisible as a round disk. as a round disk. Altostratus clouds often Altostratus clouds often form ahead of storms form ahead of storms with continuous rain or with continuous rain or snow.snow.


Altocumulus CloudsAltocumulus Clouds

• Altocumulus cloudsAltocumulus clouds are mid level clouds are mid level clouds that are made of that are made of water water dropletsdroplets and appear as and appear as gray puffy massesgray puffy masses. They . They usually usually form in groupsform in groups. . If you see altocumulus If you see altocumulus clouds on a warm, clouds on a warm, sticky morning, be sticky morning, be prepared to see prepared to see thunderstorms late in thunderstorms late in the afternoon. the afternoon.


StratusStratusLow CloudsLow Clouds


Stratus CloudsStratus Clouds

• Stratus cloudsStratus clouds are are uniform uniform grayishgrayish clouds that often clouds that often cover the entire skycover the entire sky. . They They resemble fogresemble fog that doesn't reach that doesn't reach the ground. the ground. Light Light mist or drizzlemist or drizzle sometimes sometimes falls outfalls out of these clouds. of these clouds.


Stratocumulus CloudsStratocumulus Clouds

• Stratocumulus Stratocumulus cloudsclouds are are low, low, puffy and graypuffy and gray. Most . Most form in form in rows with rows with blue sky visible in blue sky visible in betweenbetween them. them. Rain Rain rarely occursrarely occurs with with stratocumulus stratocumulus clouds, however, clouds, however, they can turn into they can turn into nimbostratus nimbostratus clouds. clouds.


Nimbostratus CloudsNimbostratus Clouds

• Nimbostratus Nimbostratus cloudsclouds form a form a dark gray, wet dark gray, wet looking cloudy looking cloudy layerlayer associated associated with continuously with continuously falling rain or falling rain or snow. They often snow. They often produce produce precipitation that precipitation that is usually light to is usually light to moderate.moderate.


Vertical Vertical Growth Growth CloudsClouds


Cumulus Cumulus CloudsClouds

• Cumulus cloudsCumulus clouds are are white, puffywhite, puffy clouds that clouds that look like pieces of look like pieces of floating cottonfloating cotton. . Cumulus clouds are Cumulus clouds are often called often called "fair-"fair-weather clouds".weather clouds". The The base of each cloud is base of each cloud is flat and the top of each flat and the top of each cloud has rounded cloud has rounded towerstowers. When the top of . When the top of the cumulus clouds the cumulus clouds resemble the head of a resemble the head of a cauliflower, it is called cauliflower, it is called cumulus congestus or cumulus congestus or towering cumulus. towering cumulus. These clouds These clouds grow grow upwardupward and they can and they can develop into giant develop into giant cumulonimbus clouds, cumulonimbus clouds, which are thunderstorm which are thunderstorm clouds.clouds.


Cumulonimbus CloudsCumulonimbus Clouds • Cumulonimbus Cumulonimbus

cloudsclouds are are thunderstorm cloudsthunderstorm clouds. . High winds can flatten High winds can flatten the top of the cloud the top of the cloud into an anvil-like into an anvil-like shape. Cumulonimbus shape. Cumulonimbus clouds are associated clouds are associated with heavy rain, snow, with heavy rain, snow, hail, lightning and hail, lightning and even tornadoes. The even tornadoes. The anvil usually points in anvil usually points in the direction the the direction the storm is moving. storm is moving.

http://ed101.bu.edu/StudentDoc/Archives/fall05/ymaini/thunderstorm.htm


Special Special CloudsClouds


Mammatus CloudsMammatus Clouds

• Mammatus Mammatus cloudsclouds are are low low hanging bulges hanging bulges that droop from that droop from cumulonimbus cumulonimbus cloudsclouds. . Mammatus clouds Mammatus clouds are usually are usually associated with associated with severe weathersevere weather..


Lenticular CloudsLenticular Clouds

• Lenticular Lenticular cloudsclouds are are caused by a caused by a wave wind wave wind patternpattern created created by the by the mountainsmountains. They . They look like discs or look like discs or flying saucersflying saucers that that form near form near mountainsmountains..


FogFog • FogFog is a is a cloud cloud on the groundon the ground. It . It is composed of is composed of billions of tiny billions of tiny water dropletswater droplets floating in the floating in the air. Fog exists if air. Fog exists if the atmospheric the atmospheric visibility near the visibility near the Earth's surface is Earth's surface is reduced to 1 reduced to 1 kilometer or less.kilometer or less.


ContrailsContrails• ContrailsContrails are are condensation condensation trails left behind trails left behind jet aircrafts.jet aircrafts. Contrails form Contrails form when hot humid when hot humid air from jet air from jet exhaust mixes exhaust mixes with with environmental air environmental air of low vapor of low vapor pressure and low pressure and low temperature. The temperature. The mixing is a result mixing is a result of turbulence of turbulence generated by the generated by the engine exhaust.engine exhaust.

Ready….Ready….

Guess the cloud type!Guess the cloud type!

StratocumulusStratocumulus

http://www.notre-planete.info/geographie/http://www.notre-planete.info/geographie/climatologie_meteo/nuages.phpclimatologie_meteo/nuages.php

CumulusCumulus


ContrailsContrails

http://ksjtracker.mit.edu/wp-content/uploads/http://ksjtracker.mit.edu/wp-content/uploads/2007/08/contrails400.jpg2007/08/contrails400.jpg

CirrocumulusCirrocumulus

www.petertan.com www.petertan.com

CirrostratusCirrostratus

Photographer: Simon Eugster --Photographer: Simon Eugster --Simon 13:08, 8 Apr 13:08, 8 Apr 2005 (UTC) 2005 (UTC)

http://commons.wikimedia.org/wiki/User:Simon

MammatusMammatus

http://www.monkeytime.org/Site%20Images/http://www.monkeytime.org/Site%20Images/mammatus.jpgmammatus.jpg

NimbostratusNimbostratus


StratusStratus

http://www.csulb.edu/~rodrigue/geog140/lectures/http://www.csulb.edu/~rodrigue/geog140/lectures/humidity.htmlhumidity.html

CumulonimbusCumulonimbus


FogFog

http://upload.wikimedia.org/wikipedia/commons/thumb/http://upload.wikimedia.org/wikipedia/commons/thumb/1/14/Mount_Lushan_-_fog.JPG/445px-Mount_Lushan_-1/14/Mount_Lushan_-_fog.JPG/445px-Mount_Lushan_-

_fog.JPG_fog.JPG

AltostratusAltostratus

http://commons.wikimedia.org/wiki/http://commons.wikimedia.org/wiki/Image:Altostratus_cumulus_1.JPGImage:Altostratus_cumulus_1.JPG

CirrusCirrus

http://www.raggedcastle.com

http://www.raggedcastle.com/

LenticularLenticular

http://apod.nasa.gov/apod/ap050821.htmlhttp://apod.nasa.gov/apod/ap050821.html

http://www.world3d.com/http://www.world3d.com/lenticularClouds.htmllenticularClouds.html

More Lenticular CloudsMore Lenticular Clouds

http://www.crystalinks.com/http://www.crystalinks.com/lenticular.htmllenticular.html

AltocumulusAltocumulus

http://mmem.spschools.org/http://mmem.spschools.org/grade5science/weather/grade5science/weather/

altocumulus.htmlaltocumulus.html


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