Clouds and Precipitation

Jake Howard

Adiabatic Temperature Changes and Expansion & CoolingWhen air is heated, it becomes less

dense and rises above the cooler air, it continues to expand because of the lesser amounts of pressure as it goes higher into the atmosphere.

The molecules need energy to spread out, which makes them vibrate slower. This causes the temperature of these air molecules to drop. This is adiabatic cooling.

http://www.kidsgeo.com/geography-for-kids/0070-adiabatic-temperature-changes.php

Orogrpahic Lifting

Orographic Lifting is when an air mass is forced from a low elevation to a higher elevation.

As the air mass gains altitude it cools down which will increase the relative humidity to 100% and create clouds.

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

Frontal Wedging

Frontal wedging is when warm air and cool air collide, this produces a front.

The cooler air acts as a barrier and the warmer air rises. The cooler air is denser and the warmer air is less dense.

This process, like orographic lifting, also lifts air and is a weather producer.

http://www.geo.hunter.cuny.edu/~tbw/wc.notes/4.moisture.atm.stability/frontal_wedging.htm

Convergence

When air in the lower atmosphere flows together, lifting happens.

When air flows from multiple directions if must go somewhere.

The uplifting of these winds coming from different directions ends up forming a clouds.

http://www.jamstec.go.jp/e/about/press_release/20080313/

Localized Convective Lifting

On hot days, usually in the summer, the earth’s surface is heated unequally. This could possibly cause pockets of air to me warmer than the surrounding air.

The rising parcels of warmer air are thermals. When thermals rise about the level of condensation clouds will form.

http://www.richhoffmanclass.com/chapter4.html

Stability Air stability is measured by the temperature

of the atmosphere and different heights.Stable air will not rise by itself, but some

processes will force this air above the surface of the Earth, which will then form clouds. These clouds are often huge and generate thunderstorms.

Warmer air is less dense. And example of density difference in stability is a hot air balloon. A hot air balloon will continue to rise as long as the air inside it is warmer than the surrounding air, therefore less dense.

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

CondensationWhen something changes

from a gas to a liquid. The opposite of vaporization.

Happens when vapor is cooled or compressed to its highest possible saturation.

For example it could form on the wing of an airplane that is traveling through a low pressure area.

Types of clouds There are 4 types of clouds, High, Low,

Middle, and Vertical. There are different clouds which fall under these types.

High CloudsThin clouds that are

blown long ways by the wind. They move across the sky west to east.

They are usually involved with good weather.

They often cover the entire sky.

Middle CloudsMiddle clouds are altostratus

clouds.They are formed by water

droplets and appear gray or blue and fluffy.

Sometimes parallel waves across the sky.

These clouds might appear on a warm summer morning, signaling that a thunderstorm may come later in the day.

Often cover the entire sky.

Low CloudsLow clouds are stratus

clouds.They are they gray

clouds that cover the entire sky.

Do not usually produce precipitation.

When thick fog lifts it forms these clouds.

Clouds of Vertical development

These are called cumulus clouds.Look like pieces of floating cotton.The base of these clouds is often flat.They are the large clouds, they can

sometimes turn into storm clouds.

FogA collection of water

droplets in the air on or near the earths surface.

It is a type of stratus cloud.

The amount of fog depends on the place because the moisture that forms it is created locally.

Cold cloud Precipitation

Warm Cloud precipitation

Rain and Snow

Sleet, Glaze, and Hail