Clouds and Precipitation By: Alaina Kleehttp://www.wpclipart.com/weather/rain_water/rain_cloud_BW.png.html
Adiabatic Temperature Changes and Expansion and Cooling• Temperature changes that happen even though heat isnt added or subtracted• When air expands it cools, and when it is compressed it heats up• As air moves up into the atmosphere it expands and cools http://www.kidsgeo.com/geography-for- kids/0070-adiabatic-temperature-changes.php
Orographic Lifting• When elevated land acts as a barrier to air flow• As the air goes up, adiabatic cooling usually occur and causes clouds and precipitation• By the time air gets to the http://www.myoops.org/twocw/usu/Fores t__Range__and_Wildlife_Sciences/Wildlan leeward side of a d_Fire_Management_and_Planning/Unit_ mountain , most of the air 7__Atmospheric_Stability_and_Instability_ 3.html moisture is gone.
Frontal Wedging• Warm and Cold air collide making a front.• Cooler/denser air is a wall to warm air, the warm air rises.• Another way to lift air http://www.geography.hunter.cuny.edu/~tbw/ wc.notes/4.moisture.atm.stability/frontal_wed ging.htm
Convergence• this is where the air that flows in more than one direction goes.• lifting is the result of air in the lower atmosphere flowing together. http://www.panoramio.com/photo/195• Air flow from the ocean 11021 along the coast leads to a pileup of air and general convergence over the peninsula.
Localized Convective Lifting• unequal heating can cause pockets of air to be warmed more than the surrounding air on the Earth’s surface.• thermals are the rising parcels of warmer air. http://wps.prenhall.com/esm_lutgens_fo undations_4e/47/12104/3098876.cw/co• humans use these ntent/index.html thermals for hang gliding and birds use it to soar through the sky with ease.
Stability (Density Differences & Stability and daily weather)• unstable air tends to rise, while stable air tends to remain in its original position.• expansion can cause the volume of air that is forced to rise, to have a drop in temperature.• When stable air resists vertical movement it causes unstable air to rise freely.
Condensation• When water vapor in the air changes to a liquid.• Many times it will either be in the form of fog, dew, or clouds.• This only occurs if air is http://www.signsoflightstore.net/newgallerym saturated aker14STORE.php?mytitle=interesting
Types of clouds• Cirrus clouds appear as patches or as feather- like wispy fibers.• Cumulus clouds appear to look like rising domes or towers.• Stratus clouds tend to look like sheets or layers that cover most of the sky. http://en.wikipedia.org/wiki/File:Clouds.JPG
High Clouds• Cirrus, cirrocumulus, and cirrostratus make up these clouds.• The cirrocumulus clouds are fluffy, while the cirrostratus clouds are flat layers.• Often made up of ice crystals because of low temperatures and small http://www.bigbranch.net/high%20clouds.htm quantities of water vapor present at high altitudes
Middle Clouds• These are also known as altocumulus clouds.• They also have larger, denser, rounded masses compared to cirrocumulus clouds.• Are a uniform white to grayish sheet covering http://www.bigbranch.net/middle%20clouds.h the sky with the sun or tm moon visible as a bright spot.
Low Clouds• Stratus, stratocumulus, and nimbostratus are what make up these clouds.• Rarely do these clouds have precipitation and if they do it’s a light amount. http://patschilling.com/pages/otherlandscapes• Nimbostratus clouds .html are the main producers of precipitation
Clouds of Vertical Development• Clouds that don’t fit into any of the three height categories.• The bases are normally in the low height range but can extend upward into the middle or high altitudes.• These are clouds that grow dramatically under http://thestormking.com/tahoe_nuggets/Nugg the proper circumstances et_87/nugget_87.html
Fog (by cooling and by evaporation)• Appearance wise, there is no difference between a fog and a cloud.• The only difference between them is the method and place of formation.• Generally the result of radiation cooling or the movement of air over a cold surface. http://lupusincolor.blogspot.com/2011/01/lup us-fog.html
Cold Cloud Precipitation (Bergeron process)• Relies on two physical processes: supercooling and supersaturation• Pure water suspended in the air isn’t supercooled until it has reached 0°C• When the air appears to be supersaturated to the http://www.atmo.arizona.edu/students/c ice crystals, the ice ourselinks/spring07/nats101s2/lecture_n crystals can’t coexist with otes/mar30.html water droplets.
Warm Cloud Precipitation (collision- coalescence process)• Clouds located well below the freezing level may have plenty of rainfall.• The collision-coalescence process is the mechanism that forms raindrops in warm clouds.• Water vapor can be removed from the air at relative humidities less http://claremont327.blogspot.com/2009/11/cl ouds-and-precipitation.html than 100 percent with water-absorbing particles.
Rain and Snow• Rain is drops of water that fall from a cloud.• Snowflakes melt and continue their descent as rain before they reach the ground.• Light, fluffy snow made up of individual ice crystals form when http://snowpictures.net/Snow- storm.html there are low temperatures in the air.
Sleet, Glaze and Hail• The fall of small particles of clear-to- translucent ice, known as sleet.• Freezing rain or the result of raindrops http://www.waterencyclopedia.com/Ce- becoming supercooled, Cr/Climate-Moderator-Water-as-a.html known as glaze.• Cumulonimbus clouds are produced by hail.