Aim: How is our atmosphere structured? Do Now: Watch the video

Atmosphere: - the layers of gas that surrounding Earth.

I. Changes in Pressure - Atmospheric pressure is the weight of the air molecules above you. - measured with a barometer (units = millibars)

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At sea level, there is 1 atm of pressure. - The atmosphere thins as you travel away from Earth’s surface. (less molecules) Where would you expect to find the most pressure? Where would you expect to find the least pressure? At sea level (1 atm) On a mountain peak WHY? WHY? At sea level, there is 1 atm of pressure. (this is all the gas molecules are above your head weighing down on you)

- A decrease in gas molecules Pressure is highest at sea level = 1.0 atm. As altitude increases air pressure decreases. At the top of the Stratosphere the pressure comes close to 0 atm. Why does the pressure approach zero as altitude increases? - A decrease in gas molecules Sea level ESRT page 14

II. Changes in Temperature: a measure of the average kinetic energy in a substance. (particle movement) measured with a thermometer ESRT p. 13 - Units of temperature include Celsius Fahrenheit Kelvin

Describe the temperature change with altitude in the: - Changes in temperatures help indicate the different layers of the atmosphere. Describe the temperature change with altitude in the: Troposphere: Stratosphere: INDIRECT DIRECT ESRT page 14

III. Layers of the Atmosphere

* Between each layer is a boundary that separates the layers called a “pause”. What features do you notice take place in the different layers of the atmosphere? Makes no sense without caption in book

What is the lowest temperature in the Troposphere? Troposphere: (where we live!) 90% of all gases all clouds and weather Temp. decreases as altitude increases What is the lowest temperature in the Troposphere? -550C Describe the relationship between temperature and altitude in the Troposphere.

What is the highest temperature in the stratosphere? Contains the Ozone Layer (blocks dangerous ultraviolet radiation). Temperature increases as altitude increases. What is the highest temperature in the stratosphere? - 00C Describe the relationship between temperature and altitude in the Stratosphere.

Contains Jet Streams; which are high speed winds that influence our daily weather.

At what altitude does the Mesosphere begin? Meteoroids burn up due to friction with air particles forming “shooting stars”. Temp. decreases as altitude increases. Describe the relationship between temperature and altitude in the troposphere. At what altitude does the Mesosphere begin? - 30mi or 50km

4. Thermosphere Temperature increases as altitude increases. Describe the relationship between temperature and altitude in the troposphere. Temperature increases as altitude increases. Contains the ionosphere (charged particles) creating the “Aurora’s” or The Northern & Southern Lights

Aurora (Northern Lights)

5. Exosphere Is the uppermost layer of the atmosphere. Contains Earth’s Satellites Last layer before space

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Closure: