2. Atmospheric Structure

3. Atmospheric Structure Five Layers of the Atmosphere 12 km ( 38,000 feet ). ( approx. 7 miles ) 47 km ( 150,000 feet ). (approx. 28 miles) 80 km ( 250,000 feet ). ( approx. 48 miles ) 0 km ( 0 feet ) Exosphere 350 km - ∞

5. Atmospheric Structure : General Trends Going Upward Through the Atmosphere

6. Tempera ture Changes The temperature drops as you rise through the troposphere. The temperature rises as you rise through the stratosphere. The temperature drops again as you rise through the mesosphere. The temperature rises again as you rise through the thermosphere. However, the air is very thin up here!

7. Changes in Temperature & Chemical Composition with Increasing Altitude N 2 O 2 Ar CO 2 H 2 O O3O3 N 2 NO + O 2 NO + O 2 N 2 Sunlight warms Earth’s surface and lower troposphere Temp drops through the mesosphere. O 2 absorbs solar radiation to warm the thermosphere.

8. 1 % of mass in mesosphere, thermosphere and exosphere combined About 19 % of mass in stratosphere 80% of mass in troposphere 10% drop in pressure at each new stage going upward Changes in Pressure and % Mass with Increasing Altitude 1000 mb 100 mb 10 mb 1.0 mb 0.1 mb.01 mb.001 mb Exosphere

9. Atmospheric Structure : Layer by Layer

10. The Lower Layers of the Atmosphere : Troposphere and Stratosphere

11. IA. Troposphere (0 – 12 km (38,000 feet) is the home of almost all of our weather:

12. IA. Troposphere Most cloud activity is limited to the troposphere, where low-lying stratus and fluffy cumulus clouds are found.

13. Troposphere Clouds low-lying stratus and fluffy cumulus clouds Stratus Cumulus

14. Troposphere Clouds Stratocumulus – a combination of layered and puffy (common near oceans). Stratocumulus

15. Troposphere Clouds When stratus clouds reach down to ground level, they become fog.

16. IA. Troposphere The troposphere is thicker at the equator than at the poles.

17. IA2. Jet Stream (12 km) Flowing along the top of the weather systems of the troposphere are the river-like jet streams.

18. IA2. Jet Streams These upper level winds travel in a generally west to east direction at speeds of up to 1 9 0 miles per hour!

19. IA2. Jet Streams The jet streams are “sandwiched” between the troposphere and the stratosphere. Troposphere Stratosphere

20. IA2. Jet Streams There are two main jet streams in North America: Polar Jet Stream – rides along the edge of the polar air mass

21. IA2.2) Jet Streams The Sub-Tropical Jet Stream is a little less changeable and usually flows from west to east across Mexico and the southern United States.

22. IA2.2) Jet Streams Polar Jet Tropical Jet

23. IA2.2) Jet Streams Watch out when they merge or come close and then diverge! The result will be severe weather: snow storms, thunderstorms or even tornadoes. Merging Jet Streams Diverging Jet Streams

24. IA2.2) Jet Streams Polar Jet Tropical Jet Upper Air Divergence

25. Polar and Tropical Jet Stream Movement over a 5 Day Period

26. Tornadoes

27. Hurricanes

28. Mid-Level Clouds The upper troposphere is home to mid- level clouds such as:a) altocumulus

29. Mid-Level Clouds The upper troposphere is home to mid- level clouds such as:a) altostratus

30. IB. Stratosphere (12 – 47 km (150,000 feet) the calm, clear layer directly above the troposphere.

31. Stratospheric Clouds The stratosphere only contains cirrus clouds, which are made of tiny ice crystals.

32. Stratospheric Clouds Cirrocumulus Cirrostratus (note the halo.) Other stratospheric (high altitude) clouds. Notice the “cirro - ” prefix.

33. Stratospheric Clouds Towering cumulonimbus thunderheads start out in the troposphere, but quickly grow and punch a hole into the stratosphere.

34. Stratospheric Clouds Cumulonimbus thunderheads Developing thunderhead From above… From below…

36. Nacre is the colorful “mother of pearl” lining found on the inside of abalone and oyster shells. Somebody decided that the iridescent colors of nacreous clouds resembled the colors seen in these nacre shell linings.

37. Ozone Layer The stratosphere is also home to the ozone layer (20 – 47 km). The ozone layer gets depleted more during some years than it does during others. In 2003, the second worst “ozone hole” ever recorded was measured:

38. 2003 Ozone Hole

39. Ozone – O 3 Side Note: the ozone molecule consists of three oxygen atoms held together by covalent bonds. The ozone layer also causes the surprising warming of the air that occurs while rising upward through the upper stratosphere.

40. The Lower Layers of the Atmosphere : Troposphere and Stratosphere

41. The Middle Layers of the Atmosphere : Mesosphere and Thermosphere

42. IC. Mesosphere (47 – 80 km (250,000 feet) The mesosphere is the middle layer of the atmosphere. Air temperatures starts to get colder again with increasing altitude. Air temperature drops to – 90 o C at the top of the mesosphere.

43. IC. Mesosphere The most distinctive features of the mesosphere are the meteors (“shooting stars”) which blaze across the sky as they burn up when the atmosphere grows denser. Meteors Meteorite

44. Noctilucent clouds form WAAYYY up (250,000 feet up) in the mesosphere, where water condenses onto “meteor smoke”!!

45. ID. Thermosphere/Ionosphere (80 – 350 km*) The ionosphere is full of charged particles ( ions ) and is found in the lower part of the thermosphere. The ionosphere is the layer of the atmosphere which interacts with the solar wind to create the Northern Lights: ( Aurora borealis ) and Southern Lights ( Aurora australis ). ( * up to 500 – 600 km during “Solar Max”)

47. The Upper Layers of the Atmosphere : Thermosphere and Exosphere 350 km

48. Thermosphere And Exosphere International Space Station (Thermosphere) Auroras (Thermosphere) Noctilucent Clouds and Meteors (Mesosphere) Thermosphere Exosphere

49. IE. Exosphere (350 km* - ???) At the outermost edge of the thermosphere is the exosphere, which continues until it merges with the interplanetary gases of outer space. The exosphere is primarily made of Hydrogen and Helium, like most of the rest of the universe. ( * The lower edge, called the exobase, can be as high as 500 – 600 km during a Solar Maximum, such as in 2012-2013.)

50. IE. Exosphere The tallest clouds poke into the stratosphere. Above them lie the dark recesses of the exosphere and outer space. ( Moon is in the distance. ) Show Globallift Video Now

51. IE2. Magnetosphere Extending far above earth is the invisible magnetosphere, or magnetic field of Earth. It is not part of Earth’s atmosphere. However, it connects and interacts with the Sun’s magnetic field and deflects the particles of the solar wind toward the magnetic north and south poles.

52. IE2. Magnetosphere That is why the auroras are usually found up near the Arctic Circle in North America and Europe. P.S. – The aurora near the South Pole is called the Aurora australis : the “Southern Lights”.

53. Earth’s Magnetosphere Solar Wind

54. Atmospheric Composition

55. II.Composition - % by Volume of Gases in the Atmosphere #1.Nitrogen (N 2 ) - 78.08% #2.Oxygen (O 2 ) - 20.95 % #3.Argon (Ar) - 0.93 % #4.Carbon dioxide (CO 2 ) - 0.035 % #5.Neon (Ne) - 0.0018 % #6.Helium (He) - 0.00052 % } “The Big 3” 99.96 % Oxygen (O 2 ) Molecule

56. II.Composition - % by Volume of Gases in the Atmosphere #7.Methane (CH 4 ) - 0.00014 % #8.Krypton (Kr) - 0.00010 % #9. Nitrous oxide (NO 2 ) = 0.00005 % #10. Hydrogen (H 2 ) = 0.00005 % (5 ppm) #11. Ozone (O 3 ) - 0.000007 % (0.07 ppm) #12. Xenon (Xe) - 0.000009 % (0.09 ppm) *** Variable Gases - Water Vapor - 0 - 4% - Volcanic Ash/Dust - trace

57. Although CO 2, CH 4 and O 3 are only present in tiny amounts, they play a huge role in the atmosphere: #4: CO 2 (Carbon dioxide) and #7: CH 4 (Methane) are the two most common greenhouse gases which warm and may eventually overheat our planet. Methane Hydrates

58. Although CO 2, CH 4 and O 3 are only present in tiny amounts, they play a huge role in the atmosphere: #11: Ozone (O 3 ) is considered a pollutant here at the surface, but 30 km up in the stratosphere, it forms the thin ozone layer which is crucial in protecting life on land from the sun’s harmful ultra-violet radiation. 2015 Ozone Hole

59. The %s are based on dry air (no water vapor). Although there is always some water present in air, the % of atmospheric water vapor never gets higher than 4 %.

60. #3 Ar (Argon) #5 Ne (Neon) #6 He (Helium) #8 Kr (Krypton) #12 Xe (Xenon) *These gases do not chemically react with the other gases or with the rocks or life forms on the surface. are all inert gases*. }

61. Nitrogen (N 2 ) is also nearly inert, which is why it has accumulated to the #1 spot. Earth actually has far more Oxygen (O 2 ) than Nitrogen! However, Oxygen (#2) is highly reactive, so much of Earth’s Oxygen is tied up in its rocks and ocean water.

63. Jet Stream IONOSPHERE LAYER EXOSPHERE NACREOUS CLOUDS

66. IA2.2) Jet Streams Los Angeles New York