THE ATMOSPHERE CH 11 SECTION 1 ATMOSPHERIC BASICS NOTES Opt. HW: Friday Jan 15 SHORT TEST: Friday Jan 15

1.Contains gases suitable for life Oxygen, Carbon dioxide MAJOR FUNCTIONS OF EARTH’S ATMOSPHERE I. FUNCTION OF THE ATMOSPHERE

2. Blocks/Filters harmful radiation from Sun

Sun’s Energy Electromagnetic Radiation (Electromagnetic Spectrum) A series of radiant energy waves of varying wavelengths From Shortest to Longest wavelength: Gamma, X-rays, Ultraviolet, Visible, Infrared, Radio 99% of solar energy is in the form of Ultraviolet, Visible Light, & Infrared (heat) energy

How much gets through our atmosphere and reaches the surface? All radio & visible light 10% of UV Some infrared None of the Gamma or X-ray

3. Distributes heat around Earth Sun’s energy drives weather systems on Earth Sun heats Earth unevenly. Air moves in an attempt to equalize the uneven heating

4. Protection from most meteoroids

II. ATMOSPHERIC COMPOSITION Permanent Atmospheric Gases Nitrogen (79%)Oxygen (21%) Argon (.93%)Carbon dioxide (.038%)

Variable Atmospheric Gases Water Vapor (0-4%) Ozone (.0012 %) – Most found in stratosphere. Tropospheric ozone generally is not naturally occurring, but is from human activity. It is one of the main culprits in the production of smog. Carbon dioxide – increased over the last 150 years due to burning of fossil fuels. Aerosols – microscopic particles suspended in the air. Dust, salt, ice

Classified into 5 different layers based on composition and temperature changes III.LAYERS OF THE ATMOSPHERE

Troposphere  Nearest to Earth’s surface  Height: 0 to about 12 km above the surface  Temperature decreases with increase in height  The “weather layer” - Contains all the weather we expereince  Commercial planes fly at upper limit.  Temperatures stop decreasing at tropopause  Contains 99% of the mass of Earth’s atmosphere

Stratosphere  Height: 12 km to about 50 km.  Temperature is stable initially, then increases with increasing height.  Contains “Ozone Layer” – region of high concentration of ozone (O 3 )  Ozone layer absorbs 90% of ultraviolet radiation from the sun.  Top of stratosphere called stratopause. Temperature stabilizes again.

Mesosphere  Height: 50 km to about 85 km.  Temperature decreases with height  Top of mesosphere called the mesopause

Thermosphere  Height: 85 km to about 600 km  Temperature increases with height  Contains the “ionosphere” region of charged gas particles. Electrons stripped from the atoms.  Site of Auroras in northern and southern high latitudes

Exosphere  Outer most layer  Height: 600 km to about 10,000 km  Transitional layer to “outer space”  Atoms so far apart they rarely collide

Aurora Borealis and Aurora Australis (Northern & Souther Lights) Emission of light as charged particles (positive and negative ions) in thermosphere interact with incoming solar particles

Taken from the International Space Station

STRUCTURE OF EARTH’S ATMOSPHERE ACTIVITY ASSIGNMENT: Construct a diagram that illustrates the correct structure of Earth’s atmosphere along with many of its characteristics. Sources for Information: Notes, textbooks (Use Ch. 17 p. 480 as a good starting pt.) Specific Requirements, Restrictions or Limitations Diagram Section - Labels. The only words allowed are: (You don’t have to use them all) tropospherestratosphere earth’s surface mesospherethermospheresun miles kilometerstropopause stratopausemesopause Numbers, pictures and symbols, chemical formulas can be used anywhere on the diagram Neatness counts

Diagram Section – The following information has to be represented/illustrated without words: The use of at least 5 colors Diagram Title (centered at the top ) The 4 layers of the atmosphere Thickness of each layer Path of UV rays, X-ray, and Gamma ray from the sun. Path and source of Radio waves The amount of Uv rays that make it to the surface from the sun The amount of Gamma and X-ray radiation that make it to the surface from the sun. Temperature Increase within a layer Temperature Decrease within a layer Weather Layer (where most clouds, precipitation, etc occur) Charged Particles Ozone concentration Altitude of planes Auroras Concentration of most of the atmospheric gases The beginning of outer space Atlitude at which meteors/shooting stars become visible. Legend/Key Information. Create a neat legend/key box to explain the following: Colors Illustrations and symbols

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A good starting place is this diagram or you can find a similar one in one of the Earth Space textbooks on the counter.

ENERGY TRANSFER IN THE ATMOSPHERE All materials are made of particles (atoms & molecules for example). Particles are always moving. Objects/Particles in motion possess 2 types of energy:

1. Kinetic Energy - Energy of moving objects All particles possess kinetic energy.

2.Thermal Energy - The total energy of particles in an object due to their random motion. The transfer of thermal energy is called Heat Heat always flows from area of higher thermal energy to area of lower thermal energy

3 Methods of Transferring Thermal Energy 1. Radiation  Transfer of thermal energy by electromagnetic waves  Ultimate Source is the sun  Enters Earth’s atmosphere and is absorbed and reflected by Earth’s atmosphere and surface.  Most is in the form of visible light and infrared

 Enters Earth’s atmosphere and is absorbed and reflected by Earth’s atmosphere and surface.  Most is in the form of visible light and infrared

 Earth’s surface absorbs much of the visible light and re-emits it as infrared at different wavelengths.  The atmosphere absorbs some of the sun’s infrared and re-emits it at a different wavelength.

 About 30% of solar radiation is reflected back into space by Earth’s surface, atmosphere, or clouds.  20% is absorbed by Earth’s atmosphere and clouds.  50% is absorbed by Earth’s surface and keeps Earth warm.

 Rate of absorption depends on many factors such as color and texture of the surface, angle at which radiation strikes the surface, and composition of the surface.

2. Conduction – Energy transfer when two particles/objects collide or in contact with one another  Most effective with solids Least effective with gases

In the atmosphere this occurs only between Earth’s surface and the lowest part of the troposphere.

3. Convection – transfer by movement of heated material from one place to another place.  Most effective in liquids & gases.  Due to heated material becomes less dense and will begin to rise.  In atmosphere, parcels of air are warmed, become less dense than surrounding air and rise. As they rise they begin to cool and become denser than surrounding and sink.

CONVECTION on a very small scale.

CONVECTION on medium scale. Land/Sea Breezes

CONVECTION on a global scale  Convection currents as this process of air motion is called in the main mechanism that thermal energy is distributed in Earth’s atmosphere.

A summary of how all 3 work together to keep us warm. 1.Solar energy passes through space by way of radiation. 2.Solar energy that is not blocked in the upper atmosphere reaches the surface and is aborbed. 3.Air in contact with the surface is heated by conduction. 4.The heated air becomes less dense and rises and convection begins. 5.The formation of convection currents distributes heat throughout the planet.