CLOUDS AND PRECIPITATION

By: Anthony Perno

Adiabatic Temperature Change and Expansion and Cooling

http://www.bio.georgiasouthern.edu/bio-home/harvey/lect/lectures.html?

flnm=abel&ttl=Introduction&ccode=rm&mda=scrn When air is compressed or allowed to

expand When air expands it cools, when it

compress it warms Dry adiabatic rate is the cooling or

getting warmer in unsatured air

Orographic Liftinghttp://www.examiner.com/outdoorsman-in-salt-lake-city/understanding-why-utah-has-the-greatest-snow-on-earth-part-1-orographic-lifting

Mountains act as barriers to air flow When air goes up a mountain, cooing

often makes clouds and precipitation By the time the air reaches the leeward

side most of the moisture is gone

Frontal Wedginghttp://www.geo.hunter.cuny.edu/~tbw/wc.notes/4.moisture.at

m.stability/frontal_wedging.htm

Warm and cold air collide, producing a front

Cooler, denser air acts as a barrier as the warmer, less dense air rises

Weather-producing fronts are associated with storm systems

Convergencehttp://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/cld/dvlp/

cnvrg.rxml

When air flows from more than one direction it flows upward because it can’t go down

Leads to adiabatic cooling and clod formation

Air movement and the rise of it is helped by solar heating of the land

Localized Convective Liftinghttp://wps.prenhall.com/esm_lutgens_foundations_4e/47/12104/3

098876.cw/content/index.html

When warm air rise’s above the condensation level, clouds form

Air that is warmer and less dense than the air around the less dense air will move upward

The process that produces rising thermals is localized convective lifting

Stability http://www.ux1.eiu.edu/~cfjps/1400/stability.html

Air that is cooler and more dense tends to sink to its original position which is stable air

If the air is warmer and less dense than the surrounding air it will began to rise, this is called unstable air

When stable gets forced into the Earth’s surface clouds that are formed widespread and have little thickness

Condensationhttp://keep3.sjfc.edu/students/kes00898/e-port/condensation

%20page%20for%20unit.html

Happens when water vapor in the air turns into liquid

For any of this to happen the air must be saturated

Saturation occurs when the air is cooled to its dew point

Types of Cloudshttp://eo.ucar.edu/webweather/cloud3.html

Basic form’s of clouds are cirrus, cumulus, and stratus

Cirrus- clouds are high white and thin

Cumulus- a pile of clouds

Stratus- a layer of clouds that cover most of the sky

High Cloudshttp://www.bigbranch.net/high%20clouds.htm

All high clouds are thin and white Not considered precipitation makers Sometimes made up of ice crystals

because low temperature and small amount on water vapor presents at high altitudes

Middle Cloudshttp://www.bigbranch.net/middle%20clouds.htm

Clouds that are in the middle of the sky Altocumulus clouds are composed of

rounded masses Altostratus clouds create a uniform white

sheet covering the sky

Low Cloudshttp://eo.ucar.edu/kids/sky/clouds1.htm

These clouds are developed in stable air Three members in the low cloud family:

stratus, stratocumulus, and nimbostratus Sometimes these clouds can produce

light precipitation

Clouds of Vertical Developmenthttp://www.free-online-private-pilot-ground-school.com/Aviation-

Weather-Principles.html All related to one

another and all have unstable air

Clouds have their bases in the low height range but tends to rise upward into the middle

When clouds move upward and acceleration is powerful clouds with great vertical range form

Fog http://www.flhsmv.gov/safetytips/Fog.htm

Fog is pretty much a cloud near or on the ground’s surface

Fog can form when enough water vapor is added to the air

When fog is dense enough its visibility is a few meters or less, making it hard to see when driving

Cold Cloud Precipitation http://www.boston.com/bigpicture/2010/04/earth_day_2010.html

Cloud droplets do not freeze at 0 degrees Freezing nuclei can cause supercooled

water to freeze Any left over water vapor becomes ice

that lowers the relative humidity near the rest of the other droplets

Warm Cloud Precipitationhttp://rst.gsfc.nasa.gov/Sect14/Sect14_1d.html

Some water-absorbing particles can remove water vapor from the air at relative humidities less than 100%

When bigger water droplets move throw the air they collide with smaller ones

Rainfall an be associated with clouds located below the freezing level

Rain and snowhttp://zahiym5tlc.edublogs.org/

Rain means drops of water falling from a cloud

Snowflakes usually melt before they hit the ground and turn into rain as they fall

There are light and fluffy snowflakes and ice crystals join into larger clumps to make then harder

Sleet, Glaze and Hailhttp://www.nelsoncountylife.com/2009/01/27/no-snow-yet-

sleet-in-valley-so-far/

Sleet is small particles of clear ice falling from cloud

Glaze is freezing rain that when raindrops becomes super cooled as they fall threw the air

Hail is made in cumulonimbus clouds

THE END!!!!!!!!!!!!!!