5lwood

CLOUDS AND PRECIPITATION

By: Luke Wood

Adiabatic temperature changes(expansion and cooling) Wet adiabatic rate is the process of air releasing

latent heat as the process of condensation starts. When you travel up in the atmosphere there are

fewer gas molecules, since there are fewer molecules the air begins to expand and cool

when air goes deeper into our Earth the air pressure increases and the air condenses this rate of heating or cooling is called dry adiabatic rate.

Orographic lifting

When any raised land or manmade feature blocks air flow orographic lifting begins.

As air goes up a mountain side the adiabatic cooling begins and creates precipitation

Frontal Wedging

When warm and cold air collides a front begins to form. At these fronts cool dense air acts as a barrier which blocks the warmer less dense air from raising this is called frontal wedging.

Convergence

If air is coming from more than one direction it have only one place to go and that is up.

When the air gets lifted into the air it leads to adiabatic cooling and possible cloud formation.

Localized Convective Lifting Is the constant flow of warmer air during

days of uneven heating. This uneven heating cause thermal to form these thermal are air pockets that carry things in the air once the warm air have stopped flowing a cloud will form.

Stability

Air that resists moving vertically is called stable air Unstable air rises freely

Clouds will not form where stable conditions are present. Stable air clouds are very wide but have small vertical height.

Unstable clouds are high over the surface and generate thunderstorm or maybe a tornado.

Condensation

Condensation is a process that happens when water vapor in the air changes to a liquid(air must be saturated)

If there is not a surface of water vapor to condense on condensation will not happen

Condensation nuclei are the surface needed for water vapor to condense if nuclei are not there a relative humidity much 100 percent is needed

Types of clouds

There are 3 basic forms of cloud cirrus, cumulus, and stratus clouds are put into these categories based on the form and height.

Cirrus- clouds that are high and thin have a faded streak like appearance

Stratus-are very flat and act as a blanket because the cover they entire sky

Cumulus-these clouds are made up of many other cloud masses in my opinion they look like explosions with a flat base.

High clouds

3 types of clouds are in the “high cloud” region cirrus, cirrostratus, and cirrocumulus

All high clouds are thin white streaks often made of ice crystal

These types of clouds are often called precipitation makers but if these clouds begin to cover most of the sky they could warm oncoming rain clouds.

Middle clouds

Middle clouds are composed of rounded masses

Altocumulus are large dense cloud These clouds create grayish white

sheets across the sky

Low Clouds

Three member stratus, stratocumulus, nimbostratus

Dark fogy layer of clouds Produce light precipitation

Clouds of vertical development

These clouds do not fit into the 3 cloud height categories

Associated with unstable air

Fog

Created by radiation cooling or the movement of air above a cold surface.

Fog is defined by having its base close to or on the ground

Cooling, causes clouds when warm moist air moves over a cold surface (land or water) then is carried into show by prevailing winds also fog can be caused at night when the earth cools quickly and air is in contact with the ground

Cold cloud precipitation

Is formed by the Bergeron process Ice crystals grow at the expense of

cloud droplets until they are large enough to fall

Warm Cloud Precipitation Is formed by the collision and coalescence

process When the relative humidity is below 100%

water absorbing particles such as salt remove water droplets from cloud. These removed drop run into other small slower droplets and fall to the ground.

Rain and Snow

Rain is a drop of water that come from clouds and are bigger the .5mm

Rain is caused by melting ice crystals in temperatures above 4 degrees Celsius

Snow is formed at very low temperature and is made up of ice crystals that join together into larger snowflakes

Sleet, Glaze and Hail

Sleet is the fall of small articles of clear or see threw ice for this to form a layer of air with temperature below freezing must overlie and subfreezing layer.

Glaze happens when rain drops become “super-cooled” below 0 degrees Celsius

Hail- hailstones begin in cumulonimbus clouds and grow bigger by collecting super-cooled water droplets as they fall through other clouds

THE END

WORK CITED http://cl0uds.wordpress.com/2009/02/04/14/ slide 1 http://www.bio.georgiasouthern.edu/bio-home/harvey/lect/lectures.h

tml slide 2

http://www.waterencyclopedia.com/Ce-Cr/Climate-Moderator-Water-as-a.html slide 3

http://www.wou.edu/las/physci/taylor/gs106/atm2_precip_files/frame.htm#slide0004.htm slide 4

http://www.sci.uidaho.edu/scripter/geog100/lect/05-atmos-water-wx/05-part-7-atmos-lifting-fronts/ch5-part-7a-atmos-liftin.htm slide 5

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 slide 6

http://ocw.usu.edu/Forest__Range__and_Wildlife_Sciences/Wildland_Fire_Management_and_Planning/Unit_7__Atmospheric_Stability_and_Instability_1.html slide 7

WORK CITED http://www.westendwindows.co.uk/condensation/ slide 8 http://eo.ucar.edu/webweather/cloud3.html slide 9 http://www.allstar.fiu.edu/aerojava/fltenv3.htm slide 10 http://www.beijinghikers.com/v2/resources/news/hiking-photos-switch

back-great-wall-2009-12-16/ slide 11

http://anthonyjstewart.wordpress.com/2009/05/28/chicago-low-clouds-and-mist/ slide 12

http://apollo.lsc.vsc.edu/classes/met130/notes/chapter6/lift_intro.html slide 13

http://articles.sfgate.com/2005-08-19/news/17387430_1_fog-san-francisco-bay-area-summer slide 14

http://www.liveweatherblogs.com/weatherblog/5568/Clouds-Precipitation-as-earth-s-thermostat slide 15

WORK CITED http://

www.nature.com/scitable/knowledge/library/introduction-to-the-basic-drivers-of-climate-13368032 slide 16

http://www.cco.caltech.edu/~atomic/snowcrystals/ slide 17 http://www.kaiserroof.com/hail/ slide 18