1. Chapter 1: The Earth’s Atmosphere By the end of this chapter you should: By the end of this chapter you should: Know the different between weather and climate Know the different between weather and climate Understand what is in the air you breathe Understand what is in the air you breathe Know how the atmosphere is layered above your head Know how the atmosphere is layered above your head

2. What is Meteorology?  Aristotle first defined meteorology in Meteorologica  What was a meteor during that period?  He defined a meteor as anything and everything that fell from the sky.  Examples include _________ and _________. rain snow  Now meteorology is the study of its atmosphere and its related phenomena.

3. Weather and Climate  What is weather?  Weather is the condition of the atmosphere at any given time  So a statement of weather would be____________________________. the temperature is 86°F  Another is - the sky was cloudy this morning.

4. Elements of Weather Air temperature Air temperature Weather can be described many ways: Air pressure Air pressure Humidity Humidity Clouds Clouds Precipitation Precipitation Visibility Visibility Wind Wind

5. What Is Climate?  What is climate?  The study of weather over a long period of time  So a statement of climate would be___________________________________. the average temperature for today is 86°F  Another is - San Francisco is usually cloudy in August.  Climate deals with averages  “Climate is what you expect, weather is what you get”

6. Weather and Climate in Our Lives Wind chill, cold weather Wind chill, cold weather

7. Fig. 1-16, p. 19

8. Weather and Climate in Our Lives Crop damage from cold weather, freeze Crop damage from cold weather, freeze

9. Weather and Climate in Our Lives Hot weather, drought, heat stroke Hot weather, drought, heat stroke

10. Weather and Climate in Our Lives Hot weather, drought, heat stroke Hot weather, drought, heat stroke

11. Weather and Climate in Our Lives Severe thunderstorms, tornadoes, flooding Severe thunderstorms, tornadoes, flooding

12. Weather and Climate in Our Lives Severe thunderstorms, tornadoes, flooding Severe thunderstorms, tornadoes, flooding

13. Overview of the Earth’s Atmosphere Credit: NASA Earth’s atmosphere is no thicker than the relative thickness of the skin on an apple.

14. Composition of the Atmosphere Two category of gases: Two category of gases:Permanent Variable ______ balanced by ______ Output input Output and input not always balanced in time and place Example of a variable gas is ____________. water vapor

15. Table 1-1, p. 3

16. Source and Removal of Nitrogen (N 2 ) Abundant because mainly inert Abundant because mainly inert Removed by soil bacteria, ocean plankton Removed by soil bacteria, ocean plankton Source is from decaying plants and animals, volcanoes Source is from decaying plants and animals, volcanoes

17. Source and Removal of Oxygen (O 2 ) Removed when plant and animals decay Removed when plant and animals decay Removed in chemical processes when oxygen combines with other stuff Removed in chemical processes when oxygen combines with other stuff Removed during breathing Removed during breathing Source is from plants during photosynthesis (CO 2 + water = sugar and oxygen) Source is from plants during photosynthesis (CO 2 + water = sugar and oxygen)

18. Source and Removal of Water Vapor (H 2 O vapor) Very, very important Very, very important Varies greatly in place and time Varies greatly in place and time Removed when precipitation falls to surface Removed when precipitation falls to surface Source is from evaporation, sea wind Source is from evaporation, sea wind Only substance in lower atmosphere as gas, liquid, and solid

19. Source and Removal of Carbon Dioxide (CO 2 ) Occupies small portion of atmosphere So what is the big deal? Occupies small portion of atmosphere So what is the big deal? Removed during ______________. CO 2 is stored in roots and branches Removed during ______________. CO 2 is stored in roots and branches Removed by the _______ (massive storage - 50 times atmospheric content) Removed by the _______ (massive storage - 50 times atmospheric content) photosynthesis Source is burning of fossil fuels (stored CO 2 ), deforestation, vegetation decay, exhalation, volcanoes Source is burning of fossil fuels (stored CO 2 ), deforestation, vegetation decay, exhalation, volcanoes oceans Past measurements come from ice cores

20. Fig. 1-4, p. 5

21. Two-faced Ozone (O 3 ) Largest concentration in the stratosphere (above 10 km) Largest concentration in the stratosphere (above 10 km) Good in upper atmosphere, absorbs ultraviolet radiation Good in upper atmosphere, absorbs ultraviolet radiation Bad near the surface, irritates eyes and throats. Main ingredient of photochemical smog Bad near the surface, irritates eyes and throats. Main ingredient of photochemical smog

22. Other Stuff in the Atmosphere Aerosols Aerosols Ash from ________ Ash from ________ Salt from wind blown saltwater Salt from wind blown saltwater Dust from wind (dust devils) Dust from wind (dust devils) Pollutants Pollutants Nitrogen dioxide, carbon monoxide, hydrocarbons, sulfur dioxide Nitrogen dioxide, carbon monoxide, hydrocarbons, sulfur dioxide Volcanoes

23. A Changing Atmosphere The earliest atmosphere The earliest atmosphere Most likely made of of ________ and ________ Most likely made of of ________ and ________ So light they escaped to space So light they escaped to space Subsequent atmosphere Subsequent atmosphere Volcanoes put gas, outgassing, (water vapor, CO 2, and some nitrogen) into environment Volcanoes put gas, outgassing, (water vapor, CO 2, and some nitrogen) into environment Water vapor produced rain for thousands of years, CO 2 into oceans, nitrogen became abundant Water vapor produced rain for thousands of years, CO 2 into oceans, nitrogen became abundant hydrogen helium

24. How Is the Atmosphere Structured? What is above our heads? What is above our heads?

25. Air Pressure and Air Density Air density (_______ per ______) Air density (_______ per ______) Gravity holds molecules to surface (most dense near surface) Gravity holds molecules to surface (most dense near surface) Air pressure (______ per ____) Air pressure (______ per ____) Always decreases with height Always decreases with height Air pressure changes with changing air density Air pressure changes with changing air density Sea-level pressure Sea-level pressure Pressure is weight pushing down on your head Pressure is weight pushing down on your head Atmospheric standards (14.7 lbs per square inch=1013.25 millibars (mb)=29.92 inch Hg) Atmospheric standards (14.7 lbs per square inch=1013.25 millibars (mb)=29.92 inch Hg) weight volume force area

26. Fig. 1-7, p. 8

27. Fig. 1-8, p. 9

28. Layers of the Atmosphere

29. Troposphere Temperature generally __________ with height Temperature generally __________ with height Cools due to ____ heating surface Cools due to ____ heating surface Temperature increasing with height is called an inversion Temperature increasing with height is called an inversion Contains all weather we know Contains all weather we know decreases sun

30. Stratosphere Is characterized by ____________ air temperature Is characterized by ____________ air temperature Height of tropopause varies in height Height of tropopause varies in height Ultraviolet light is absorbed in the stratosphere, ________ the layer Ultraviolet light is absorbed in the stratosphere, ________ the layer increasing warming

31. Mesosphere Temperature _____________ rapidly once again Temperature _____________ rapidly once again Air very thin Air very thin decreasing

32. Thermosphere Just a small amount of absorption leads to warming Just a small amount of absorption leads to warming Warmer than troposphere, but you would still freeze to death in it Warmer than troposphere, but you would still freeze to death in it

33. The Ionosphere Electrified regions of the atmosphere Electrified regions of the atmosphere D, E, and F regions D, E, and F regions D region is efficient at absorbing AM radio waves, thus these waves don’t travel very far D region is efficient at absorbing AM radio waves, thus these waves don’t travel very far But, at night, the D region dissipates, allowing for AM waves to bounce off the E and F regions But, at night, the D region dissipates, allowing for AM waves to bounce off the E and F regions

34. Fig. 1-11, p. 13