Earth’s Circulation

1. Earth’s Circulation Atmospheric Circulation Ocean Circulation

2. Circulation is the way Earth moves ocean water and atmosphere

3. General Circulation of the Atmosphere: start with surface winds

4. Surface Winds: Follow Pressures • Flow high to low • Coriolis • Friction

5. First step – naming winds

6. Trade WindsFlow tothe Intertropical Convergence Zone Hadley Cells • Touch at ITCZ • Rising air over Doldrums • Fed by Easterly Trade Winds

7. Trade Winds Carry Dust Mali Dust Plume blowing from the east

8. Classroom Resource Watch trade winds flow from east to west, Different visuals of flow of moisture

9. Your tropical vacation and the trade winds

10. ITCZ: Rain Maker

11. Lion King: Rain Came from ITCZ movement, following the sun

12. Classroom Resources Watch ITCZ move north and south Sahel: at the margin of the ITCZ, so some years lots some little

13. Descending air

14. A big cause of deserts is descending air, right under subtropical high

15. Subtropical High Pressures are “centered” in oceans

17. Classroom Resource Watch westerly winds flow from west to east Different visuals of flow of moisture

18. Polar Front: zone of storms from convergence of westerly winds and polar easterly winds

19. Polar Easterlies - Flowing from Polar High to Polar Front (low)

20. Air descends

21. Now – add the vertical in 3D

22. Continents break up the high pressures and make reality look more like circulation cells

23. “center” of the precipitation peaks are the belts of low pressure: ITCZ and the 2 polar fronts

25. Jet Streams direct our storms

26. Different Patterns

27. For dry Southwest toget winter rains, need: • Winter time for jet stream to shift south

28. For SW to get winter rains, need: • Meridional pattern • The “trough” to be over SW

29. Polar Jet separates cold/warm

30. Cold outbreaks in East when jet moves in cold air

31. Ocean Circulation around Gyres

32. warm currentstransport energy

33. Surplus in Tropics moved to higher latitudes by warm currents

34. Larger Picture

35. Classroom Resources Gulf Stream 3D perspective

36. What would happen if Gulf Stream slowed or didn’t go far enough? Gulf stream & North Atlantic Drift Classroom Resource

37. It happened in Younger Dryas

38. “The Day After”: decades not days Classroom Resource

39. Cold Currents: Upwelling & Rich Nutrients result in Marine Resources

40. Classroom Resources Focus on Peru to introduce El Nino Movie with labels

41. Classroom Resources

42. ENSO: El Nino Southern Oscillation “Normal” or more typical (La Nina is the more normal state) Trade winds push warm water & storms to East Pacific

43. Part of the “Walker Cell” Trade winds and warm water supplies energy (storms) to Northern Australia and Indonesia, while Peru is dry from descending air

44. ENSO: El Nino Southern Oscillation • Trade winds decrease • warmth & storms move eastward against South America • Upwelling ceases • Marine food chain collapse

45. A Flip-flopacross theSouthPacific (pressures oscillate)

46. On Average 7 yrs apart ENSO- red

47. In review:

48. In review:

49. Online Resources El Nino/La Nina Visualizations http://serc.carleton.edu/NAGTWorkshops/visualization/collections/elnino_lanina.html Oceanography Animations http://serc.carleton.edu/NAGTWorkshops/visualization/collections/oceanography.html Ocean Upwelling and Circulation http://serc.carleton.edu/NAGTWorkshops/visualization/collections/circulation_upwellings.html Ocean Surface Currents http://serc.carleton.edu/NAGTWorkshops/visualization/collections/surfacecurrents.html

50. Circulation is the way Earth moves ocean water and atmosphere