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Atmosphere-Gases that surround our planet.

I. Composition of Air (Highest to Lowest)A. NitrogenB. Oxygen

C. ArgonD. Carbon DioxideE. HydrogenF. NeonG. HeliumH. KryptonI. XenonJ. Radon(Just a trace)*K. Humidity-amount of water vapor in the air. It varies from 1 to 4% byvolume on the average. It is highest over bodies of water and underhigh amospheric temperature when evaporation is rapid.

II. Properties of AirA. 99% of mass of atmosphere is found in the botttom 30 km.B. Atmospheric density decreases with increasing altitude.C. Atmospheric pressure decreases with increasing altitude.D. More than half of the air molecules are found in the bottom 5.5 km.E. At sea level, atmospheric pressure=14.7 lb/in2 = 1 atm(atmosphere) = 1013.25 N/cm2 = 1013.25 mb (milibar)F. Atmospheric density is inversely directed to air temperature.

III. Major Divisions of the Atmosphere (According to Temperature

Variations)A. Troposhere-Bottom 16 to 18 m of the atmosphere where winds,clouds, water vapor are found and where weather phenomena occur. Itis warmer near the equator and colder towards the pole, thus, the airgrows colder as one goes up higher.B. Stratosphere-Lies above the troposphere, the air grows warmer asone goes up higher. Its average depth is above 30km and its outerboundary is around 50km above sea level.C. Mesosphere-Air grows coldly as one goes up higher as the gases inthis region do not absorb the suns rays.D. Thermosphere-Layer next to the mesosphere thats made of very

thin air that is heated by the suns rays, making its temperaturesometimes rise to 1000 degrees Celsius.

IV. Divisions Based on Distribution of Gases in AtmosphereA. Homosphere-located at the bottom 90km of the atmosphere wherethere is continuous movement of air massesl thus, gases such as N2and O2 are mixed. The term homosphere is derived from the prefixhomo (meaning same), referring to the relatively homogeneous mixtureof gases in this region, except for the ozone layer that envelops theglobe at around 30km above sea level.B. Heterosphere-Outer portion of atmosphere where no mixing ofgases takes place, thus, gases tend to separate in layers. The term

heterosphere is derived from the prefix hetero(meaning different),referring to the unmixed gases in this region.

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V. Divisions based on Distribution of Ozone and IonsA. Ozonosphere-The bottom 70km of the atmosphere, ozone in theozone layer is also called the stratospheric zone.B. Ionosphere-Region of the atmosphere which is sufficiently ionizedby solar ultraviolet radiation. This is the outer portioin of the

atmosphere where ions and electroncs are trapped by Earthsmagnetic field and form layers referred to simply as D, E, and F layers.They reflect radio waves back to Earth, and tehrefore play a veryimportant role in radio transmission.

VI. Movements of AirA. Convection Cell/Hadley Cell

Part 1: The rise of warm air oveer equator cools at hightemperature.Part 2: Warm air descends in horizontal movement/Better knownas wind.

*There are 3 convection cells per hemisphere, 3 in the north and 3 in

the south.

B. ITCZInternational Convergence ZoneMeeting of trade winds at about 5 degrees north and 5 degrees southof the equator.It is not stationary, as it moves north or south of the equator with theseasons, father over land than over the ocean because of variations inocean temperature.

C. Sea BreezeOccurs in daytime, cool, gentle wind from sea is produced when warmair over land rises then the colder air over the sea moves toward theland.

D. Land BreezeOccurs in nighttime, warm air in the sea rises, colder wind over landmoves toward the sea.

E. DoldrumsLow pressure zone of rising warm moist air

Area of calm or equatorial belt of calms located between 5 degreesnorth and 5 degrees south of the equator.Areas where hurricanes originate.

F. Trade WindsHorizontal wind movement

VI. Lighting and ThunderstormsA. Benjamin Franklin-First scientist to observe the very nature oflighting.B. Thunderstorms-Usually small

C. Troposphere-Reason for thunderstorms

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Convection-Air becomes warmer, a.k.a updraft-rise of the hotair.

D. Causes/Factors affecting ThunderstormsMoisture supplies thunderstormsInstability in the atmosphere, a mechanical lifting that rises to

cause thunderstorms.Clouds cannot hold in rain anymore, and gravity causes therainfall.

*The details arent complete, download the remaining inpowerpoint form at:http://www.mediafire.com/?p5nyob0cpandp8b