Clouds

By: Reland Saugling

Orographic Lifting

• As elevated terrain act like barrier to air, orographic lifting occurs.

• Clouds and precipitation are created when air goes up a terrain, then adiabatic cooling occurs.

• when air gets to the leeward side, most of the moisture is gone, if air descend it make condensation and precipitation unlikely.

https://earthscience-in-the-nationalparks.wikispaces.com/Death+Valley

Frontal wedging

• Frontal wedging is when cool air and warm collide

• Weather producing fronts have to do with specific storm system such as middle latitude cyclones

http://www.ldeo.columbia.edu/BRG/ODP/ODP/LEG_SUMM/171A/leg171A.html

Convergence

• Convergence is when different air masses collide and forces air to be lifted upward.

• Takes place in lower atmosphere.• Convergence leads to adiabatic cooling and

clouds forming.

http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/cld/dvlp/cnvrg.rxml

Localized Convective Lifting

• When unequal heating of Earth’s surface causes pockets of air to be warmed more than surrounding air.

• Thermal are warmer parcels of air that will rise because they are less dense.

• When warm parcels of air rise above condensation clouds form and clouds create mid-day rain .

http://santasusana.org/pakelly/ES9CP/ES9%20clouds.htm

Stability

• Stable air stays in the same position while unstable air will rise until it reaches an altitude were the surrounding clouds are the same temperature.

• Most stable position is temp. inversion • Air temp. increase with height because of radiation

cooling off of earths surface

http://ocw.usu.edu/Forest__Range__and_Wildlife_Sciences/Wildland_Fire_Management_and_Planning/Unit_7__Atmospheric_Stability_and_Instability_1.html-skinless_view.html

Condensation

• Takes place when water vapor changes to a liquid in the air.

• Air must be saturated for condensation to happen.

• In forms of dew, fog, or clouds.

http://www.weatherquestions.com/What_is_condensation.htm

Types of clouds

• Classified by form and height.• Cirrus clouds-thin, white, seen in patches• Stratus- clouds that appear to look like sheets

that cover the sky• Cumulus- look like dooms, consist of round

independent masses

http://www.enchantedlearning.com/subjects/astronomy/planets/earth/clouds/

High clouds

• 6000 meters and higher• Cirrus, cirrostratus, and cirrocumulus• Thin and white and often made up of ice

crystals

http://10.85.0.4:8080/ibreports/ibp/bp.html?fn=Students&fp=1&ip=10.182.1.107&ibip=10.85.0.4&ldu=0&re=0&bu=commons.wikimedia.org/wiki/File:High_Clouds_seen_from_Maui.JPG&bc=Website%20contains%20prohibited%20Adult%20Oriented%20content.

Middle Clouds

• Forms from 2000 to 6000 meters• Types alto cirrus, altostratus, and

altocumulus• Altocumulus is larger and denser while

altostratus clouds create a uniform of grayish sheets that cover the sky with sunlight seen through.

http://www.allstar.fiu.edu/aero/fltenv3.htm

Low Clouds

• Forms 2000 meters and below• Types Stratus, Stratocumulus, and

Nimbostratus• Cloud are fog like and cover most of the sky,

and sometime produce light precipitation

http://www.capetownskies.com/clouds-low.htm

Clouds of Vertical Development

• Clouds that do not fit into any height range, base is in low height range while everything else is extended upwards.

• Clouds are associated with unstable air.

• Cumulus clouds may grow upwards and form clouds with great vertical range.

• End result cumulonimbus clouds with thunderstorms .

http://www.pilotfriend.com/av_weather/meteo/clouds.htm

Fog

• Clouds and fog have similar appearance and structure.

• Fog is a cloud that has its base really close to the ground.

• Fog forms from the result of radiation cooling, movement of air over a cold surface, and when water vapor is added to bring saturation.

http://www.photoshopstar.com/photo-effects/how-create-fog-effect-photoshop/

Warm Cloud • Collision-coalescence process form rain droplets in warm

clouds • It is when water absorbing particles remove water vapor from

the air at relative humidity less than 100% forming large droplets

• When the droplets move through clouds they collide with smaller droplets.

http://www.capespirit.com/capewestcoastwallpapers.html

Cold Cloud Precipitation

• Bergeron process relies on super cooling and super saturated

• Super saturation is air that is saturated with the respect to water

• Super cooled is when water will not freeze at o degrees Celsius but at 40 degrees Celsius, but it will freeze when it hits a solid http://

www.liveweatherblogs.com/weatherblog/5568/Clouds-Precipitation-as-earth-s-thermostat

Rain and Snow

• Rain-drops of water that the diameter is at least 0.5 MM

• If the temp. is higher than 4 degrees Celsius, then snow flake will melt and become rain before it hits the ground.

• Low temperature snow makes up six side ice crystal while temp. warmer than -5 degrees Celsius will become large heavy lumps.

http://kohd.com/page/213587

Sleet, Glaze, and Hail

• Sleet forms when a layer of air with temperature of freezing, lay over a subfreezing layer near the ground.

• Glaze forms when rain drops are super cooled and fall through subfreezing air near the ground (turn to ice when collides with an object).

• Hail starts out as small ice that gets bigger by super cooled water droplets as they fall through clouds

http://weblogs.wgntv.com/chicago-weather/tom-skilling-blog/2005/03/

Adiabatic cooling

• When air is allowed to expand it cools and if it is compressed it cools.

• Unsaturated air cools at a constant rate.

• As you travel higher , the atmospheric pressure decrease because there are fewer gas molecules.

http://www.bio.georgiasouthern.edu/bio-home/harvey/lect/lectures.html?ccode=el&mda=scrn&flnm=abel&ttl=Populations%20and%20their%20environment

The End!!!!!!!!