Clouds and Precipitation Project

By: Matt Schaffer

Adiabatic temperatures changes and expansion and cooling

• When air is cool it expands and when air is warm it compresses

• The rate of cooling or heating of unsaturated air is called dry adiabatic rate

• The wet adiabatic rate is the slower rate of cooling when latent heat is added

http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/adiab.html

Orographic lifting

• Orographic lifting is when air flow is blocked• Many of the rainiest places on Earth are on the windward

side of mountain slopes• When air reaches the leeward side of a mountain the air

has lost much of its moisture

http://05lovesgeography.blogspot.com/2011/04/types-of-rainfall.html

Frontal Wedging

• In central America when masses of warm air and cool air collide it produce a front

• Warmer air is less dense and raises• Colder air is more dense and produces a

barrier over warmer air

http://www.erh.noaa.gov/rnk/Newsletter/Spring_2008/climate.htm

Convergence

• Convergence occurs when air in the lower atmosphere flows together

• Air flowing from more then one direction goes up• The Florida Peninsula is an example of convergence

http://apollo.lsc.vsc.edu/classes/met130/notes/chapter6/lift_converge.html

Localized Convective Lifting

• Unequal heating of Earth causes rising parcels of warmer air called thermals

• Localized convective lifting is the process that produces rising thermals

• Pockets of air that are warmer then surrounding air are less dense will move upward

https://www.meted.ucar.edu/sign_in.php?go_back_to=http%253A%252F%252Fwww.meted.ucar.edu%252Fnorlat%252Fsnow%252Flake_effect%252Fprint_whole.htm

Stability

• The temperatures of that atmosphere at various heights determines the air stability

• Stable air produces clouds that are widespread, have little vertical thickness compared to their horizontal dimension, and precipitation is light to moderate, if any

• Stable air resists vertical movement and air stays in its positions and unstable air rises

http://keithrogershome.com/Chap6StabilityInstability.html

Condensation

• The air must be saturated for condensation to occur(water vapor changes to liquid)

• Condensation nuclei are the surface for water vapor condensation in the air

• Their must be a surface for condensation to occur

http://keep3.sjfc.edu/students/kes00898/e-port/condensation%20page%20for%20unit.html

Types of clouds

• The three basic forms of clouds are cirrus, cumulus, and stratus

• All clouds show properties of one of the three basic cloud forms or a mixture of them

• Clouds are classified on their height and form

http://eo.ucar.edu/webweather/cloud3.html

High Clouds

• High clouds are made up of cirrus, cirrostratus, cirrocumulus clouds

• High clouds are thin and white

• High clouds are not considered precipitation makers

http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/cld/cldtyp/hgh/crs.rxml

Middle clouds

• Middle clouds are 2000 to 6000 meter high

• Have the prefix alto as part of their name

• Altocumulus clouds are larger and denser then cirrocumulus clouds

http://www.ifimages.com/public/image/139051/view.html

Low Clouds

• Low clouds are made up of stratus, stratocumulus, and nimbostratus clouds

• Stratus clouds mostly cover much of the sky

• Nimbostratus clouds come from a Latin word that means rainy cloud

http://www.cepolina.com/photo/stratus_cumulus.htm

Clouds of vertical Development

• Clouds that don’t fit into the three height ranges are associated with unstable air

• When a upward motion is triggered it will produce clouds with vertical form

http://www.free-online-private-pilot-ground-school.com/Aviation-Weather-Principles.html

Fog (by cooling and by evaporation)

• Fog can be caused by cooling or evaporation

• Fog is produced when warm air moves over cold air

• When cool air moves over warm air it condenses and rising making fog that looks like steam

http://photoshoptutorials.ws/photoshop-tutorials/photo-effects/fog.html

Cold Cloud Precipitation

• Formed by the Bergeron process

• Supercooled water is when water is in a liquid state and below 0 degrees Celsius

• Supersaturated air has 100% saturated air for water and above 100% saturated for ice

http://www.srh.noaa.gov/lzk/?n=mar2011.htm

Warm Cloud Precipitation

• The collision-coalescence process forms rain drops in warm clouds

• Larger droplets join together with smaller droplets as they move through the cloud

https://www.meted.ucar.edu/sign_in.php?go_back_to=http%253A%252F%252Fwww.meted.ucar.edu%252Ftropical%252Ftextbook_2nd_edition%252Fprint_5.htm

Rain and snow

• Rain is a drop of water that falls from a cloud and has a diameter of .5 mm

• Light snow occurs when there is a small amount of water vapor in the air

• Heavy snow occurs when temperatures are warmer than -5 degrees Celsius

http://www.mapsofworld.com/world-maps/precipitation-rain-and-snow-enlarge-map.html

Sleet, Glaze and Hail

• Small particles of clear ice are called sleet

• Freezing rain is commonly known as glaze

• Cumulonimbus clouds produce hail

http://www.theweatherprediction.com/severe/gianthail/

The End