Two solitudes - how seasonality biases drought from tree rings
Upcoming SlideShare
Loading in...5
×

Like this? Share it with your network

Share

Two solitudes - how seasonality biases drought from tree rings

  • 2,344 views
Uploaded on

Graphics prepared for an upcoming talk at the University of Arizona's Laboratory of Tree-Ring Research

Graphics prepared for an upcoming talk at the University of Arizona's Laboratory of Tree-Ring Research

More in: Technology , Spiritual
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
    Be the first to like this
No Downloads

Views

Total Views
2,344
On Slideshare
2,342
From Embeds
2
Number of Embeds
1

Actions

Shares
Downloads
36
Comments
0
Likes
0

Embeds 2

http://www.slideshare.net 2

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
    No notes for slide

Transcript

  • 1. TWO SOLITUDES how seasonality biases drought records from tree rings
  • 2. TWO SOLITUDES how seasonality biases drought records from tree rings
  • 3. why are Canadian streamflow reconstructions so lousy?
  • 4. 100% 80% 60% explained variance 40% 20% 0% Canada USA
  • 5. 100% Woodhouse et al., 2006 Meko et al., 2001 80% Sacramento River Upper Colorado River Meko et al., 2007 Colorado River Woodhouse, 2007 Middle Boulder Creek 60% explained variance 40% 20% 0% Canada USA
  • 6. 100% Woodhouse et al., 2006 Meko et al., 2001 80% Sacramento River Upper Colorado River Meko et al., 2007 Colorado River Woodhouse, 2007 Middle Boulder Creek 60% Case and MacDonald, 2003 explained Saskatchewan River Beriault and Sauchyn, 2006 Churchill River variance Bonin and Burn, 2005 Athabasca River 40% Watson and Luckman, 2005 Gedalof et al., 2007 Bow River Columbia River 20% 0% Canada USA
  • 7. why are Canadian tree rings not connected to climate modes?
  • 8. Janice Lough and Hal Fritts The Southern Oscillation and tree rings: 1600 - 1961 Journal of Applied Meteorology 24, 1985 Roseanne D’Arrigo and Gordon Jacoby A thousand year record of northwestern New Mexico winter precipitation reconstructed from tree rings and its relation to El Niño and the Southern Oscillation The Holocene 1, 1991 David Stahle and collaborators Experimental dendroclimatic reconstruction of the Southern Oscillation Stahle et al., 1998 Bulletin of the American Meteorological Society 79, 1998
  • 9. Prairie ringwidth records 138 Significant correlation with ENSO 4 Expected from random chance 6.9
  • 10. seasonality
  • 11. Trees, seasonality and climate forcings The southwestern US
  • 12. Trees, seasonality and climate forcings The Canadian Prairies
  • 13. DROUGHT AND SEASONALITY How does the connection between reconstructed drought 1 and seasonal precipitation vary across North America?
  • 14. DROUGHT AND SEASONALITY How does the connection between reconstructed drought 1 and seasonal precipitation vary across North America? CLIMATE MODES AND TREE RINGS In which regions are drought reconstructions most strongly 2 connected to remote climate forcings (ENSO, PDO, AMO)?
  • 15. The North American Drought Atlas Cook et al., 2007, Earth Science Reviews
  • 16. Cook et al., 2007, Earth Science Reviews
  • 17. CORRELATION COMPOSITES COHERENCE
  • 18. PART ONE tree rings, drought and seasonality
  • 19. significant (α=0.05)
  • 20. instrumental tree rings
  • 21. SUMM ER PRECIP ITAT ION
  • 22. WINTER PRECIPITAT ION
  • 23. do tree rings replicate these patterns?
  • 24. +
  • 25. summer mixed winter
  • 26. DOMINANT not exclusive
  • 27. “ ...the regional summer precipitation signal is strong in Pseudotsuga menziesii latewood-width [in southeastern Arizona]. David Meko and Chris Baisan Pilot study of latewood-width of conifers as an indicator of variability of summer rainfall in the North American monsoon region International Journal of Climatology 21, 2001
  • 28. Medicine Hat, Alberta Source: Environment Canada, Adjusted Historical Canadian Climate Data, 1895 – 2006
  • 29. Prairie ringwidth records 138 Significant correlation with ENSO 4 Expected from random chance 6.9 45
  • 30. ENSO and winter precipitation
  • 31. PART TWO drought records and climate modes
  • 32. ENSO PDSI from tree rings PDO AMO
  • 33. are these signals present in reconstructed drought?
  • 34. Julia Cole and Ed Cook The changing relationship between ENSO variability and moisture balance in the continental United States Geophysical Research Letters 25, 1998
  • 35. ENSO PDSI from tree rings PDO AMO
  • 36. COMPOSITES where is it wet or dry when ENSO is strong?
  • 37. ENSO PDSI from tree rings PDO AMO
  • 38. LOW frequency
  • 39. LOW FREQUENCIES (>7yr) TREE-RINGS and PDO 0.5 0.25 mean squared 61 0 coherence
  • 40. LOW FREQUENCIES (>7yr) TREE-RINGS and PDO 0.5 0.25 mean squared 61 0 coherence
  • 41. 3 Mexican PDSI 10 2 5 1 0 0 -1 -5 -2 -3 62 -10 1900 1920 1940 1960 1980 2000
  • 42. 3 PDO index Mexican PDSI 10 2 5 1 0 0 -1 -5 -2 -3 63 -10 1900 1920 1940 1960 1980 2000
  • 43. ENSO PDSI from tree rings PDO AMO
  • 44. SEAS ONALITY AND D ROUGHT
  • 45. summer mixed winter
  • 46. IMPLICATIONS 1590s
  • 47. IMPLICATIONS what/where OK
  • 48. IMPLICATIONS what/where OK what/where/why NOT OK
  • 49. IMPLICATIONS tree ring model output Celine Herwiejer, Richard Seager and Ed Cook North American droughts of the mid to late nineteenth century: a history, simulation and implication for Mediaeval drought The Holocene 16, 2006
  • 50. summer mixed winter
  • 51. M A N Y TH AN KS Dave Meko Ed Cook Hal Fritts Toby Ault