1. Atmosphere And Climate

2. Atmosphere Invisible layer of gases that surround the earth
78% nitrogen
21% oxygen
1% argon, carbon dioxide, neon, helium, water vapor, air pollutants
Atmosphere becomes less dense as you move upwards into space

3. Atmosphere Origin Gases were released from the planet itself
Functions:
Protects earth from uv rays, x-rays, cosmic rays
Allows visible light and infrared (heat) to penetrate, warming the earth
billion years ago evolution of photosynthetic organisms

4. Layers of the Atmosphere
Troposphere
Stratosphere
Mesosphere
Thermosphere
Exosphere
Memory technique: Troy smiled more than Ed

5. Layers of the Atmosphere

6. Layers of the Atmosphere

7. Troposphere
Closest to the surface of the earth, extends about 6.2 miles up
Temp. decreases with increasing altitude
Weather occurs in this layer

8. Stratosphere Extends 6.2-28 miles up Uniform temperature Jets fly here
**contains ozone layer**

9. Mesosphere
28-50 miles
Lowest temperature in atmosphere (-138oC)

10. Thermosphere
miles
Temp. rises steadily with increasing altitude
Gases absorb x-rays and short wave uv radiation
Aurora borealis occurs here

11. Aurora borealis

12. Exosphere
310 miles to space

13. Atmospheric Dynamics Atmospheric circulation
Transfers heat from equator to the poles (warm air near equator rises, then cools and sinks again)
Moderates earth’s temperature
The atmosphere circulation AND the ocean currents determine climate
Climate=avg. temp. and avg. precipitation

14. Surface Winds
Connects the earth; carrying heat, moisture, plant nutrients, and long-lived pollution
Winds are complex horizontal movement of the atmosphere
Are the result of differences in atmospheric pressure and the earth’s rotation

15. Differences in Atmospheric Pressure
Winds blow from high pressure to low pressure (the greater the difference between the high and low, the stronger the wind

16. Earth’s Rotation Earth rotates from west to east
Coriolis Effect: earth’s rotation causes the winds to be deflected to the right in the northern hemisphere and to the left in the southern hemisphere

17. Three Prevailing Winds
Winds are named for the direction they come FROM
Polar easterlies (north and south poles)
Westerlies (mid-latitudes)
Trade winds (tropics)

18. Three Prevailing Winds

19. The Ocean
Salt water covers ¾ of the earth’s surface (continuous body of water, but divided into 4 sections-Pacific, Atlantic, Indian, Arctic)
Pacific covers 1/3 of earth and contains more than ½ of earth’s water

20. Ocean Currents Caused by prevailing winds
Gyres: circular ocean currents
Influenced by Coriolis Effect
Varying density-warm water is less dense than cold water

21. Gyres

22. Weather Short term properties of the troposphere such as: Temperature
Pressure
Humidity
Precipitation
Cloud cover
Wind direction and speed

23. Fronts
Boundary between 2 air masses with different temps and densities
Warm front
Cold front

24. Warm Front
Boundary between an advancing warm air mass and the cooler one it’s replacing
Warm air is less dense, so it rises up over the mass of cooler air
First signs: high, wispy clouds
A moist warm front can bring days of cloudy skies and drizzle

25. Warm Front

26. Warm Front

27. Warm Front

28. Cold Front Leading edge of an advancing mass of cold air
Wedges underneath (more dense) the warmer air mass
Produces thunderstorms

29. Cold Front

30. Cold Front

31. Cold Front

32. Air Pressure
Caused by tiny molecules bouncing off of each other; affected by gravity
Air pressure at the earth’s surface is greatest because of the weight of all of the other air particles being pulled by gravity
High pressure
Low pressure

33. High Pressure
High, dry, cool
Winds are clockwise and out

34. Low Pressure
Low, moist warm
Winds move counterclockwise and inward

35. High Pressure/Low Pressure

36. Extreme Weather
Tornados (form over land)-each year more than 800 touch down in the US
Tropical Cyclones (form over water)
Form over Atlantic Ocean=hurricanes
Form over Pacific Ocean=typhoons
The warmer the water where the storm tracks, the more energy the storm has and the more damaging it will be

37. Tornado

38. Hurricane/Typhoon

39. Typhoons/Hurricanes Negative Impacts-deaths, property damage
Ecological Benefits:
Flushes out excessive nutrients, dead and rotting sea grass from coastal bays and marshes. This flushing out in turn:
Reduced brown tides
Increased growth of sea grasses
Increased the number of shrimp, crabs, fish

40. Climate
A region’s general pattern of atmospheric or weather conditions over a long period of time (weather is more of a day to day thing)
2 factors that determine climate:
Average temp.
Avg. precipitation

41. Climate Due to air and ocean circulation
Factors that determine global air/ocean circulation:
Uneven heating of the earth’s surface
Seasonal changes
Rotation of the earth
Long term variations in amount of solar energy striking the earth
Properties of air and water

42. Uneven heating of the earth’s surface
At the equator it is warmest because rays are direct
At the poles it is coldest because rays hit at a low angle

43. Uneven heating of the earth’s surface

44. Uneven heating of the earth’s surface

45. Seasonal Changes
The earth is tilted, sometimes toward the sun (our summer) and other times tilted away from the sun (our winter)

46. Seasonal Changes

47. Rotation of the Earth
Due to the Coriolis Effect, winds and ocean are deflected creating convection currents that transfer heat from the equator

48. Coriolis Effect

49. Long Term Variations in the Amount of Solar Energy Striking the Earth
Earth wobbles on its axis (22,000 year cycle)
Earth tilts more (44,000 year cycle)

50. Properties of Air and Water
Heat from the sun evaporates ocean water and transfers heat to the atmosphere
Convection currents circulate air, heat, and moisture
El Nińo
La Nińa
Air composition
Ozone

51. El Nińo-Southern Oscillation (ENSO)
Prevailing westerly winds weaken or cease
Surface water along the S. and N. American coasts becomes warmer
Supresses upwellings(colder, more oxygenated water that cycle nutrients)
Productivity decreases, sharp decline in some fish populations
Can trigger extreme weather changes (mild winters on east coast, stronger storms in the west)

52. La Nińa Cooling of ocean surface water Increased Atlantic hurricanes
Colder winters here and Canada
Warmer, drier winters in southern US
Wetter winters in Pacific NW
Torrential rains in SE Asia
Lower wheat yields in Argentina
More wildfires in Florida

53. El Nińo-Southern Oscillation/ La Nińa

54. Air Composition
Greenhouse gases trap wavelengths of infrared radiation (heat), warming the earth
Water vapor
Carbon dioxide
Methane
Nitrous oxide
Synthetic CFC’s (chloroflourocarbons )

55. Greenhouse Effect

56. Ozone Layer Located in Stratosphere
O2 is continuously converted into O3 (ozone) by uv radiation
Keeps 95% of harmful uv rays from reaching the earth
Provides a thermal cap so warm, churning gases do not leave the troposphere

57. Ozone Layer

58. Microclimates Local climatic conditions Caused by: Mountains Cities
Land to ocean interactions

59. Microclimates-Mountains
(Seattle) Moist air blowing inland from the ocean is forced to rise up over the mountains
Rising air expands, cools, and condenses (RECC) so precipitation occurs
As the drier air mass flows down the other side of the mountain it draws moisture from plants and soil
Rain Shadow Effect-the term for the low precipitation and semi-arid conditions on the leeward side of mountains

60. Rise, Expand, Cool, Condense

61. Microclimates-Mountains

62. Microclimates-Mountains

63. Microclimates-Cities
Concrete, asphalt, brick, and building materials absorb and hold heat and block wind flow
Haze and smog from pollutants released from vehicles create higher temps.

64. Microclimates-Cities

65. Microclimates-Land-Ocean Interactions
Ocean to land breezes during the day (sea breezes)
Land to ocean breezes at night (land breezes)

66. Sea Breeze

67. Land Breeze