1. Earth’s Atmosphere: Important Vocabulary Weather: Current conditions of the atmosphere. Climate: Average weather over long period of time. Meteorology: Study of Earth’s atmosphere

2. What is an “Atmosphere”? An atmosphere is a gas that surrounds a planet, held in by gravity.

3. The Atmosphere from Space!

4. Gases in Earth’s Atmosphere Nitrogen makes up most of Earth’s atmosphere (78%) Nitrogen makes up most of Earth’s atmosphere (78%) Oxygen (21%) exists because photosynthesis. Oxygen (21%) exists because photosynthesis. Small amounts of other gases. Small amounts of other gases. Water vapor varies depending upon location. Water vapor varies depending upon location.

7. Air Pressure Air Pressure = Force/area Air Pressure = Force/area More molecules hitting a surface means more air pressure. More molecules hitting a surface means more air pressure. Air moves from high to low pressure. Air moves from high to low pressure.

8. Check for understanding 1) What is the difference between weather and climate? 2) What is the most abundant gas in Earth’s atmosphere. 3) Why is there oxygen in Earth’s atmosphere? 4) Why is there more air pressure on the bottom of Earth’s atmosphere than the top?

9. Structure of the Atmosphere The Earth’s Atmosphere has 4 primary layers. They are called: The Earth’s Atmosphere has 4 primary layers. They are called: 1. Troposphere 2. Stratosphere 3. Mesosphere 4. Thermosphere Layers are characterized by: Layers are characterized by: 1. How temperature changes with height 2. Phenomenon that occurs in each layer

10. Troposphere Lowest layer of the Earth’s atmosphere, where weather occurs. Lowest layer of the Earth’s atmosphere, where weather occurs. Gets colder with height because air pressure decreases. Gets colder with height because air pressure decreases. 75% of the atmosphere’s mass is here. 75% of the atmosphere’s mass is here. Exists below 12 km in height Exists below 12 km in height

11. Troposphere

12. Stratosphere Where the Ozone layer is found Where the Ozone layer is found Absorbs Ultraviolet Radiation (UV), which can damage plant and animal life. Absorbs Ultraviolet Radiation (UV), which can damage plant and animal life. Gets warmer with height because of the ozone layer. Gets warmer with height because of the ozone layer.

13. Stratosphere

14. Mesosphere The coldest layer of Earth’s atmosphere (to -90 degrees Celsius) The coldest layer of Earth’s atmosphere (to -90 degrees Celsius) Friction causes meteors to break apart (Shooting stars) Friction causes meteors to break apart (Shooting stars) Perseid Meteor Shower Perseid Meteor Shower Perseid Meteor Shower Perseid Meteor Shower

15. Mesosphere

16. Thermosphere Highest level of the Earth’s atmosphere that borders outer space Highest level of the Earth’s atmosphere that borders outer space Warmest level of the atmosphere due to solar radiation Warmest level of the atmosphere due to solar radiation Where the auroras occur. Where the auroras occur. Auroras are energized gas molecules from solar radiation. Auroras are energized gas molecules from solar radiation. Aurora Video Aurora Video Aurora Video Aurora Video Aurora from ISS Aurora from ISS Aurora from ISS Aurora from ISS

17. Thermosphere

18. Heating the Earth’s Atmosphere  Earth’s weather is driven by energy received by the atmosphere from the sun.  Energy is transferred from the sun in 3 ways: -Radiation-Conduction-Convection

19. Electromagnetic Waves  All light travels in the form of electromagnetic waves.  Electromagnetic waves travel as sine waves.  As light leaves the sun, that energy is transferred through space to the Earth. This process is called radiation.

20. Properties of Waves – Wavelength and Frequency  Wavelength  Amplitude

21. Properties of Waves: Frequency Low Frequency, Long Wavelength High Frequency, Short Wavelength

22. Visible light  Visible light is the part of the electromagnetic spectrum that humans can see.  Most of the sun’s radiation is produced in visible wavelengths.  The full spectrum is abbreviated (ROYGBIV)

24. Radiation!  Radiation is the transfer of energy through electromagnetic waves.  Radiation is the only type of heat transfer that can travel through empty space.  Not all radiation is lethal to life.

27. Summary  The sun produces light in all wavelengths of the electromagnetic spectrum.  High frequency light (X-Rays and Gamma Rays) are generally absorbed in the upper atmosphere.  Ultraviolet light is absorbed by ozone in the stratosphere.  Most visible light reaches the Earth’s surface. Therefore, the atmosphere is transparent to visible light.

28. Conduction: Heat Transfer by Contact  Conduction is a type of heat transfer where thermal energy is transferred by contact.  Can only transfer heat through matter, cannot happen in space!  When you touch a hot grill by accident, heat is transferred by conduction.

29. Convection: Heat Transfer through a Fluid  A warm fluid is heated from below, becomes less dense and rises.  Areas of the fluid that are cooler sink and replace the fluid that has risen.  This current is known as convection.

30. How Solar Energy Drives the Earth’s Weather  The atmosphere is heated from below because visible light heats the Earth’s surface, not the atmosphere directly.  Air in contact with the Earth’s surface is heated by conduction.  Air at the surface is heated, expands, and rises into the atmosphere. Heat is transferred through the atmosphere by convection.

31. Sea Breeze and Convection  Sand captures heat better than water.  Temp above the sand is hotter, causing the air to rise.  Cooler air from the Sea comes to replace it.

32. Land Breeze and Convection  Water at night holds onto heat longer than sand.  The opposite effect of a sea breeze.  Cooler air from land replaces the warmer air above the water

33. Sea Breeze vs Land Breeze