CLOUDS AND PRECIPITATION

Ryan Griffo

Adiabatic Temperature changes and Expansion

Adiabatic temperature changes is when temperature changes without heat being added or subtracted.

Expansion is when the atmospheric pressure decreases.

http://www.google.com/imgres?q=adiabatic+temperature+change+and+expansion&um=1&hl=en&safe=active&sa=N&biw=1024&bih=419&tbm=isch&tbnid=1FZzmyogakHmrM:&imgrefurl=http://www.meted.ucar.edu/fire/s290/unit6/print.htm&docid=jCxLjbY5UVYhzM&imgurl=http://www.meted.ucar.edu/fire/s290/unit6/media/graphics/heat_loss_rise_swf.jpg&w=492&h=368&ei=AP0CT5OIDsrY0QGz7b2CAg&zoom=1&iact=rc&dur=213&sig=103494288338770468506&page=2&tbnh=89&tbnw=119&start=13&ndsp=14&ved=1t:429,r:0,s:13&tx=113&ty=20

Orographic Lifting Orographic lifting is when air attempts to

flow up a mountain slope, or any other elevated terrain.

Often, when air flows up a mountain adiabatic cooling generates clouds and precipitation. http://www.google.com/imgres?

q=orographic+lifting&um=1&hl=en&safe=active&sa=X&biw=1024&bih=419&tbm=isch&tbnid=pv1_iEgFf3nvCM:&imgrefurl=http://www.examiner.com/outdoorsman-in-salt-lake-city/understanding-why-utah-has-the-greatest-snow-on-earth-part-1-orographic-lifting&docid=b_HHSK7xcu11pM&imgurl=http://web.mst.edu/~rogersda/umrcourses/ge301/press%2526siever12.3.png&w=1198&h=577&ei=K_4CT6zCFuT50gHphKSbAg&zoom=1&iact=hc&vpx=177&vpy=145&dur=1534&hovh=156&hovw=324&tx=135&ty=105&sig=103494288338770468506&page=1&tbnh=63&tbnw=131&start=0&ndsp=12&ved=1t:429,r:1,s:0

Frontal Wedging

Masses of warm and cold air collide, producing a front.

Cooler, denser air acts as a barrier over which the warmer, less denser air rises.

http://www.google.com/imgres?q=frontal+wedging&um=1&hl=en&safe=active&sa=X&biw=1024&bih=419&tbm=isch&tbnid=Xkdk2cpVi_V6PM:&imgrefurl=http://www.geo.hunter.cuny.edu/~tbw/wc.notes/4.moisture.atm.stability/frontal_wedging.htm&docid=SAJwgDhUglGDhM&imgurl=http://www.geo.hunter.cuny.edu/~tbw/wc.notes/4.moisture.atm.stability/frontal.wedging.jpg&w=793&h=407&ei=af8CT6f5Osbk0QHlgJHSAg&zoom=1&iact=hc&vpx=50&vpy=149&dur=1353&hovh=161&hovw=314&tx=219&ty=87&sig=103494288338770468506&page=1&tbnh=70&tbnw=137&start=0&ndsp=13&ved=1t:429,r:0,s:0

Convergence

Convergence is whenever air in the lower atmosphere lows together, lifting results.

When air flows in from more than one direction, it must go somewhere. Because it cannot go down, it goes up.

http://www.google.com/imgres?q=converging+winds&um=1&hl=en&safe=active&biw=1024&bih=419&tbm=isch&tbnid=3SOkok7jFnAgEM:&imgrefurl=http://www.srh.noaa.gov/jetstream/synoptic/wind.htm&docid=kEP3cGiQMtM8cM&imgurl=http://www.srh.noaa.gov/jetstream/synoptic/images/airflow.jpg&w=341&h=215&ei=XAADT_uXFOjg0QHZr8RE&zoom=1&iact=hc&vpx=351&vpy=129&dur=497&hovh=172&hovw=272&tx=183&ty=70&sig=103494288338770468506&page=1&tbnh=82&tbnw=130&start=0&ndsp=12&ved=1t:429,r:2,s:0

Localized Convective Lifting

Unequal heating of the Earth’s surface sometimes cause pockets of the air to be warmed more than the surrounding air.

The process that produces rising thermals is localized convective lifting.

http://www.google.com/imgres?q=localized+convective+lifting&um=1&hl=en&safe=active&biw=1024&bih=419&tbm=isch&tbnid=2i9YsWKLYKeBsM:&imgrefurl=http://www.richhoffmanclass.com/chapter4.html&docid=eOg_tc1chzUMNM&imgurl=http://www.richhoffmanclass.com/images/chapter4/seabreeze.gif&w=585&h=325&ei=8wADT5LyEef30gG9m9i8Ag&zoom=1&iact=hc&vpx=55&vpy=134&dur=2266&hovh=167&hovw=301&tx=217&ty=115&sig=103494288338770468506&page=1&tbnh=75&tbnw=135&start=0&ndsp=12&ved=1t:429,r:0,s:0

Stability (Density Differences & Stability and Daily Weather)

Stable air resists vertical movement. Stable air tends to remain in its original

position, while unstable air tends to rise. Air stability is determined by measuring

the temperature of the atmosphere at various heights.

http://www.google.com/imgres?q=hot+air+balloon&um=1&hl=en&safe=active&biw=1024&bih=419&tbm=isch&tbnid=tFilfaGxodUQQM:&imgrefurl=http://www.flyingcoloursballoons.com/&docid=mIVzdp6QbgIaYM&imgurl=http://www.flyingcoloursballoons.com/images/DSCN0441.JPG&w=2048&h=1536&ei=pAEDT_ONBufz0gG4_rmAAg&zoom=1&iact=hc&vpx=77&vpy=107&dur=2134&hovh=194&hovw=259&tx=189&ty=202&sig=103494288338770468506&page=1&tbnh=102&tbnw=136&start=0&ndsp=15&ved=1t:429,r:8,s:0

Condensation

Condensation is when water vapor changes into liquid water.

For condensation to happen, there must be a surface for water vapor to condense on, like grass and car windows.

http://www.google.com/imgres?q=condensation&um=1&hl=en&safe=active&biw=1024&bih=419&tbm=isch&tbnid=yPfC5JbAzfFQIM:&imgrefurl=http://www.weatherquestions.com/What_is_condensation.htm&docid=gJLyZWZHxPDRQM&imgurl=http://www.weatherquestions.com/condensation.gif&w=576&h=432&ei=QAIDT82ZEuLs0gHbge2KCA&zoom=1

Types of Clouds

Cirrus clouds are clouds that are high, white and thin.

Cumulus clouds are clouds that consist of rounded individual cloud masses.

The third and last type of cloud is Stratus, which are clouds shaped as sheets or layers that cover most if not all of the sky.

http://www.google.com/imgres?q=types+of+clouds&um=1&hl=en&safe=active&biw=1024&bih=419&tbm=isch&tbnid=IoPj4RaGCnbckM:&imgrefurl=http://eo.ucar.edu/webweather/cloud3.html&docid=mW51DXr3amL99M&imgurl=http://eo.ucar.edu/webweather/images/cloudchart.gif&w=504&h=352&ei=mgIDT7fNEMrc0QGN2ohP&zoom=1

High Clouds

The three types of clouds make up high clouds: cirrus, cirrostratus, and cirrocumulus.

Cirrocumulus clouds are made up of fluffy masses, while cirrostratus clouds are flat layers.

All high clouds are thin and white and are often made up of ice crystals.

http://www.google.com/imgres?q=high+clouds&um=1&hl=en&safe=active&biw=1024&bih=419&tbm=isch&tbnid=nHjcUIl5neFVsM:&imgrefurl=http://eo.ucar.edu/kids/sky/clouds3.htm&docid=6c8pW2c1Vlrw-M&imgurl=http://eo.ucar.edu/kids/sky/images/6506_sm.jpg&w=432&h=396&ei=-gIDT8DoF4rt0gHH4pnFAg&zoom=1&iact=hc&vpx=77&vpy=86&dur=6984&hovh=215&hovw=235&tx=114&ty=182&sig=103494288338770468506&page=1&tbnh=103&tbnw=112&start=0&ndsp=12&ved=1t:429,r:0,s:0

Middle Clouds

Clouds that appear at around 2000 to 6000 meters in the sky.

Middle clouds are a white or grayish sheet covering the sky with the sun or moon visible as a bright spot.

http://www.google.com/imgres?q=middle+clouds&um=1&hl=en&safe=active&biw=1024&bih=419&tbm=isch&tbnid=eXqRzumpLMYs2M:&imgrefurl=http://www.bigbranch.net/middle%2520clouds.htm&docid=TT_dxf4tMHBfpM&imgurl=http://www.bigbranch.net/168.jpg&w=610&h=458&ei=ZQMDT53DN6bw0gGmnenCAg&zoom=1

Low Clouds

There are three types of low clouds: stratus, stratocumulus, and nimbostratus.

Most low clouds are a fog-like layer of clouds that cover most of the sky.

Low clouds are one of the main precipitation makers, and most low clouds form during stable conditions.

http://www.google.com/imgres?q=low+clouds&um=1&hl=en&safe=active&biw=1024&bih=419&tbm=isch&tbnid=JJahxomvSY5EcM:&imgrefurl=http://eo.ucar.edu/kids/sky/clouds1.htm&docid=2mgX-ZgydQMhoM&imgurl=http://eo.ucar.edu/kids/sky/images/peggy5a_sm.jpg&w=432&h=287&ei=wAMDT7uuFOX10gHErsnmBQ&zoom=1&iact=hc&vpx=207&vpy=118&dur=12181&hovh=183&hovw=276&tx=145&ty=104&sig=103494288338770468506&page=1&tbnh=86&tbnw=130&start=0&ndsp=12&ved=1t:429,r:1,s:0

Clouds of Vertical Development

Some clouds have their bases in the low height range and extend upward into middle or high altitude.

These types of clouds are associated with unstable air.

These types of clouds also do not fit into any of the three height groups.

http://www.google.com/imgres?q=cumulonimbus&um=1&hl=en&safe=active&biw=1024&bih=419&tbm=isch&tbnid=33JkpYW57KfTyM:&imgrefurl=http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/cld/cldtyp/vrt/cb.rxml&docid=QvJVg3JjDixqPM&imgurl=http://ww2010.atmos.uiuc.edu/guides/mtr/cld/cldtyp/vrt/gifs/cb2.gif&w=365&h=246&ei=NwQDT732H4ji0gH4r631CA&zoom=1&iact=hc&vpx=216&vpy=117&dur=1448&hovh=184&hovw=274&tx=164&ty=104&sig=103494288338770468506&page=1&tbnh=104&tbnw=139&start=0&ndsp=12&ved=1t:429,r:1,s:0

Fog (by cooling and by evaporation)

There is no difference between fog and clouds, the only difference is the place they’re formed at.

Fog can form on cool, clear nights when the Earth’s surface is being rapidly cooled by radiation.

When cool air moves over warm water, moisture might evaporate from the water surface to produce saturation. The rising water vapor meets with cold air, it immediately condenses and rises with the air that is being warmed from below.

http://www.google.com/imgres?q=fog&um=1&hl=en&safe=active&biw=1024&bih=419&tbm=isch&tbnid=2b17_CblCR2MuM:&imgrefurl=http://www.crh.noaa.gov/jkl/%3Fn%3Dfog_types&docid=wHqi3TdNiObcDM&imgurl=http://www.crh.noaa.gov/Image/jkl/tree-in-fog.jpg&w=500&h=375&ei=oAQDT7CzDIXX0QGomciZAg&zoom=1&iact=hc&vpx=165&vpy=107&dur=7304&hovh=194&hovw=259&tx=169&ty=122&sig=103494288338770468506&page=1&tbnh=110&tbnw=142&start=0&ndsp=13&ved=1t:429,r:1,s:0

Cold Cloud Precipitation (Bergeron process)

The Bergeron process relies on two physical processes: super cooling and super saturation.

Liquid water below zero degrees Celsius is super cooled. Super cooled water will freeze if touched by a solid object.

When air is saturated with respect to water, it is super saturated with respect to ice.

http://www.google.com/imgres?q=bergeron+process&um=1&hl=en&safe=active&biw=1024&bih=419&tbm=isch&tbnid=sJl2FacqOG9YyM:&imgrefurl=http://www.sleepingdogstudios.com/Network/Earth%2520Science/ES_18_Rev_files/slide0021.htm&docid=C2ZNPd5AIbC4qM&imgurl=http://www.sleepingdogstudios.com/Network/Earth%252520Science/ES_18_Rev_files/slide0021_image055.gif&w=196&h=351&ei=PgUDT7qUGOTh0QHB8om4Ag&zoom=1&iact=hc&vpx=542&vpy=21&dur=2025&hovh=280&hovw=156&tx=76&ty=199&sig=103494288338770468506&page=1&tbnh=104&tbnw=58&start=0&ndsp=14&ved=1t:429,r:4,s:0

Warm cloud Precipitation (collision-coalescence process) A lot of rainfall can be associated with

clouds with temperatures below the freezing level.

The part of the cloud that forms raindrops is the collision-coalescence process.http://www.google.com/imgres?

q=collision-coalescence+process&um=1&hl=en&safe=active&biw=1024&bih=419&tbm=isch&tbnid=sAmPgItqMkyHrM:&imgrefurl=http://apollo.lsc.vsc.edu/~wintelsw/MET1010LOL/chapter07/&docid=1JuLnGT6bOVWGM&imgurl=http://apollo.lsc.vsc.edu/~wintelsw/MET1010LOL/chapter07/drop_cloud_ccn.gif&w=520&h=474&ei=2AUDT5LoBcPr0gGEpcm3Ag&zoom=1&iact=hc&vpx=79&vpy=87&dur=9073&hovh=214&hovw=235&tx=137&ty=180&sig=103494288338770468506&page=1&tbnh=103&tbnw=113&start=0&ndsp=14&ved=1t:429,r:0,s:0

Rain and Snow

Rain generally means drops of water that fall from a cloud and have a diameter of at least 0.5 mm. Smaller raindrops are called drizzle.

At very low temperatures light snow made up of individual six-sided crystals' forms.

http://www.google.com/imgres?q=rain&um=1&hl=en&safe=active&biw=1024&bih=419&tbm=isch&tbnid=j7covHT5BDTWxM:&imgrefurl=http://aumusiclibrary.wordpress.com/2011/02/28/rain-helens-picks-for-a-rainy-afternoon/&docid=_sdQotVh9UyPSM&imgurl=http://aumusiclibrary.files.wordpress.com/2011/02/rain.jpg&w=485&h=335&ei=qQYDT4GaG-L50gHS-snnDg&zoom=1&iact=hc&vpx=626&vpy=114&dur=671&hovh=186&hovw=270&tx=166&ty=143&sig=103494288338770468506&page=1&tbnh=99&tbnw=132&start=0&ndsp=12&ved=1t:429,r:4,s:0

Sleet, Glaze and Hail

Sleet is the fall of small particles of clear-to-translucent ice.

Glaze results when raindrops become super cooled.

Hailstorms begin as small ice pellets that grow by collecting super cooled water droplets as they fall through a cloud.

http://www.google.com/imgres?q=hail&um=1&hl=en&safe=active&biw=1024&bih=419&tbm=isch&tbnid=8xMqG-sNerVJsM:&imgrefurl=http://stormgasm.com/photo%2520gallery/hail/hail.htm&docid=JR9eWb-jzYYIYM&imgurl=http://stormgasm.com/4-17-02LPday/tom%252520pics/hail.jpg&w=596&h=404&ei=MQcDT-i2BqT00gGp4cjKDA&zoom=1&iact=rc&dur=452&sig=103494288338770468506&page=1&tbnh=104&tbnw=135&start=0&ndsp=13&ved=1t:429,r:5,s:0&tx=67&ty=47