GEOG3839.13, Global temperature reconstructions

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GEOG3839.13, Global temperature reconstructions

  1. 1. Source: St. George and Luckman, 2001
  2. 2. Source: St. George and Luckman, 2001
  3. 3. Source: St. George and Luckman, 2001
  4. 4. a.k.a. Empirical Orthogonal Function analysisPRINCIPLE COMPONENTS ANALYSIS
  5. 5. PC1 (group 1) PC3 (group 3) PC2 (group 2)
  6. 6. Source: St. George and Luckman, 2001
  7. 7. Source: St. George and Luckman, 2001
  8. 8. most sitesSource: St. George and Luckman, 2001
  9. 9. most sites farthest northSource: St. George and Luckman, 2001
  10. 10. most sites farthest north unusual siteSource: St. George and Luckman, 2001
  11. 11. LINEARREGRESSION
  12. 12. yt = axt + b + ε
  13. 13. Tjj = 0.23PC1 + -0.23PC3t+1 + 0.16PC2t+1 + -0.09PC1t+1 + -0.46
  14. 14. Source: St. George and Luckman, 2001
  15. 15. “ Tree-ring-derived records have played a prominent role in a empts to establish how climate has varied ” in the recent past. — Jones et al., The Holocene, 2009
  16. 16. G L O B A L T E M P E R AT U R E R E C O N S T R U C T I O N SPhotograph: Marianna
  17. 17. Long, temperature-sensitive tree-ring records have been used to estimate average temperatures across the entire hemisphere or globe.Source: Esper et al., Science, 2002
  18. 18. Source: Esper et al., Science, 2002
  19. 19. Source: D’Arrigo et al., 2006
  20. 20. Source: D’Arrigo et al., 2006
  21. 21. Source: Osborne and Briffa, 2006
  22. 22. “ ...this study provides evidence for intervals of significant warmth in the [Northern Hemisphere] within the so-called Medieval Warm Period and for significantly colder intervals during the so-called ” Li le Ice Age period. — Osborne and Briffa, 2006
  23. 23. LINEARREGRESSION
  24. 24. Source: Intergovernmental Panel on Climate Change, 2007
  25. 25. Photograph: Mark Anbinder
  26. 26. “ Tree-rings also allow the reconstruction of large-scale regional or global temperature pa erns defined by large networks of chronologies. ”— Brian Luckman
  27. 27. Source: Briffa et al., Global and Planetary Change, 2004
  28. 28. h p://www.cru.uea.ac.uk/cru/people/briffa/temmaps/
  29. 29. 1883“THE LOUDEST SOUND IN MODERN HISTORY”
  30. 30. Krakatau, Indonesia 1883
  31. 31. h p://www.cru.uea.ac.uk/cru/people/briffa/temmaps/
  32. 32. 1816THE “YEAR WITHOUT A SUMMER”
  33. 33. Mount Tambora, Indonesia Its eruption in 1815 was the most explosive since AD 180
  34. 34. Source: Briffa et al., Global and Biological Change, 2004
  35. 35. h p://www.cru.uea.ac.uk/cru/people/briffa/temmaps/
  36. 36. Huaynaputina Peru
  37. 37. “Trees are not thermometers or rain gagues.” Keith Briffa and colleagues
  38. 38. THEDIVERGENCE PROBLEM
  39. 39. the ‘divergence problem’ is defined as the tendency for tree growth at some previously temperature-limited northern sites to demonstrate a weakening in mean temperature response in recent decades.Source: D’Arrigo et al., 2008
  40. 40. Source: D’Arrigo et al., 2008
  41. 41. “ It is important to stress that not all high-latitude regions display this apparent decoupling between observed and dendroclimatically estimated temperatures. ” — Jones et al., The Holocene, 2009
  42. 42. Source: Briffa et al., Global and Biological Change, 2004
  43. 43. Source: D’Arrigo et al., 2008
  44. 44. SURFACE TEMPERATURERECONSTRUCTIONSFOR T H E LAS T 2 , 00 0 Y E A R S NATIONAL RESEARCH COUNCIL OF THE NATIONAL ACADEMIES

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