1. CLIMATE An Abrupt Climate Change Scenario and Its Implications for United States National Security (Pentagon Report, 2003). Global warming “should be elevated beyond a scientific debate to a US national security concern... future wars will be fought over the issue of survival rather than religion, ideology or national honour.” Understanding climate matters...

2. CLIMATE I. Large Scale Determinants A. Solar Radiation 1. Average Radiation Budget - Solar Constant = 2 calories/cm 2 /min - 50% is reflected, absorbed, reradiated (Most ultraviolet light is reflected/absorbed) by the atmosphere - on average, 1 cal/cm 2 /min strikes earth. (but this varies dramatically, as we will see…)

3. - 50% is reflected, absorbed, reradiated (Most ultraviolet light is reflected/absorbed)

4. Greenhouse effect ABSORBANCE CO 2 fills ‘window’ in H 2 O absorbance YAY OZONE!

5. A. Solar Radiation 1. Average Radiation Budget 2. Local Radiation Budget – Angle of incidence (latitude and season) 3) More is reflected off surface; a lower percentage of what strikes/unit area is absorbed 1)Goes through more atmosphere 2)Less energystrikes/unit area (since it is spread over more area)

6. A. Solar Radiation 1. Average Radiation Budget 2. Local Radiation Budget – Angle of incidence (latitude and season)

7. HIGH ENERGYLOW ENERGY B. Effects on Atmospheric Circulation

8. HIGH ENERGYLOW ENERGY

11. As air rises: - decrease pressure - increase volume - decrease energy/unit volume - decrease temperature

12. As air rises: - decrease pressure - increase volume - decrease energy/unit volume - decrease temperature Decrease temp, increase tendancy of water vapor to condense “Adiabatic cooling”

13. PV = nRT As air rises: - decrease pressure - increase volume - decrease energy/unit volume - decrease temperature Decrease temp, increase tendancy of water vapor to condense “Adiabatic cooling”

14. As dry cold air falls: - increase pressure - decrease volume - increase energy/unit volume - increase temperature “Adiabatic warming”

15. Increase temp of this dry air, evaporate water off surface As dry cold air falls: - increase pressure - decrease volume - increase energy/unit volume - increase temperature “Adiabatic warming” 30 o N 30 o S

16. 30 o N 30 o S TROPICAL RAINS at solar equator HOT, DRY, DESERTS

17. 30 N 30 S

18. Latitude of solar equator drive seasonal rainy seasons in tropics Latitude of solar equator

19. Three cycles in each hemisphere: Hadley temperate (Ferrel), polar

20. Transfer of energy from equator to poles (“Why are global warming’s greatest effects at the poles, not in raising the temperature of the tropics?)

21. - Pattern of air movement along the surface of the earth… C. The Coriolis Effect

22. -Pattern of air movement along the surface of the earth… - conservation of momentum east - speed relative to Earth changes (treadmill analogy) C. The Coriolis Effect

24. D. Effects on Ocean Circulation

27. E. Long-Term Effects 1. ENSO (El Nino Southern Oscillation)

28. E. Long-Term Effects 1. ENSO (El Nino Southern Oscillation)

29. E. Long-Term Effects 1. ENSO (El Nino Southern Oscillation)

30. 2. Younger Dryas - Dramatic cooling of northern Europe 11,000-13,000 years ago, correlating with the melting of the Laurentian Ice Sheet in North America. - Fresh water formed a lens on surface; deflecting Gulf Stream to the east at a much lower latitude, starving Europe of the heat transferred by the Gulf Stream. E. Long-Term Effects

31. F. Difficulties in Modeling Global Climate 1. Positive Feedback Loops

32. F. Difficulties in Modeling Global Climate 1. Positive Feedback Loops

33. F. Difficulties in Modeling Global Climate 1. Negative Feedback Loops

34. II. Determinants of Local Climate A. Topography 1. mountains

35. Merriam’s Life Zones in the southwestern U.S.

37. Valleys - Day II. Determinants of Local Climate A. Topography 1. mountains 2. valleys

38. Valleys - Night II. Determinants of Local Climate A. Topography 1. mountains 2. valleys

39. II. Determinants of Local Climate A. Topography 1. mountains 2. valleys 3. slope face

40. B. Water Bodies - act as heat sink/source as temp changes more slowly than air SPRING to SUMMER Land warms more rapidly than water body; heat transfers to cold water...increase in temp is buffered

41. B. Water Bodies - act as heat sink/source as temp changes more slowly than air FALL to WINTER Land cools more rapidly than water body; heat transfers to cold land...decrease in temp is buffered

42. B. Water Bodies - act as heat sink/source as temp changes more slowly than air Continental climateMaritime climate focus on temp (red) and NOTE scales differ!! CONTINENTAL CLIMATE MARITIME CLIMATE

43. B. Water Bodies - also a source of moisture

44. B. Water Bodies - also a source of moisture Maritime climate

45. B. Water Bodies also a source of moisture Continental climate (max 100)Maritime climate (max 160) focus on precip (blue)

46. B. Water Bodies -also a source of moisture - depends on onshore vs. offshore winds/currents Vancouver, 49N Boston, 42 N Note differences in scale

47. C. Additive Effects - Atacama Desert

48. D. Seasonality in Temperate Lakes