Seasonality of Moisture-Sensitive Tree-Ring Records Across North America
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Presentation given at PAGES 2K meeting in Tucson, Arizona, October 28, 2011.
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Seasonality of Moisture-Sensitive Tree-Ring Records Across North America
- 3. MY DISSERTATION PROPOSAL “...this project will establish a new network of moisture- sensitive tree-ring sites within the WRB that will allow researchers to estimate hydroclimatic conditions in the basin during the past 200 – 500 years.”
- 4. X MY DISSERTATION PROPOSAL “...this project will establish a new network of moisture- sensitive tree-ring sites within the WRB that will allow researchers to estimate hydroclimatic conditions in the basin during the past 200 – 500 years.”
- 5. 100% MORE CERTAIN 80% 60% explained variance 40% 20% LESS CERTAIN 0% Canada USA
- 6. 100% MORE CERTAIN 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% LESS CERTAIN 0% Canada USA
- 7. 100% MORE CERTAIN 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 Saskatchewan River explained Beriault and Sauchyn, 2006 Churchill River Bonin and Burn, 2005 variance Athabasca River 40% Watson and Luckman, 2005 Gedalof et al., 2007 Bow River Columbia River 20% LESS CERTAIN 0% Canada USA
- 8. SEASONALITY
- 9. QUESTION What is the seasonality of moisture-sensitive tree-ring records across North America?
- 11. QUESTION drought What is the seasonality of moisture-sensitive tree-ring records across North America?
- 12. NORTH AMERICAN DROUGHT ATLAS h p://www.ncdc.noaa.gov/paleo/pdsi.html
- 13. Source: Cook et al., Earth Science Reviews, 2007
- 14. INSTRUMENTAL PDSI WINTER SUMMER total precipitation total precipitation
- 15. INSTRUMENTAL TREE-RING PDSI PDSI WINTER SUMMER WINTER SUMMER total precipitation total precipitation total precipitation total precipitation
- 16. Point-to-point correlations, Summer Precipitation & Summer PDSI (Instrumental) St. George et al., The Holocene, 2011
- 17. 0.0 0.2 0.4 0.6 Point-to-point correlations, Summer Precipitation & Summer PDSI St. George et al., The Holocene, 2010
- 18. 0.0 0.2 0.4 0.6 Point-to-point correlations, Winter Precipitation & Summer PDSI St. George et al., The Holocene, 2010
- 19. Seasonal precipitation ‘bias’ of NADA St. George et al., The Holocene, 2010
- 21. WINTER-SENSITIVE SUMMER-SENSITIVE RECORDS RECORDS
- 22. WINTER-SENSITIVE SUMMER-SENSITIVE RECORDS RECORDS HIGH spatial coherence STRONG connections to remote forcings GOOD hydrological proxy
- 23. WINTER-SENSITIVE SUMMER-SENSITIVE RECORDS RECORDS HIGH spatial coherence LOW spatial coherence STRONG connections to MODEST connections to remote forcings remote forcings GOOD hydrological proxy POOR hydrological proxy
- 25. ENSO (the Cold Tongue Index) correlated against reconstructed summer PDSI St. George et al., The Holocene, 2010
- 26. QUESTION drought What is the seasonality of moisture-sensitive tree-ring records across North America?
- 27. Seasonal precipitation ‘bias’ of NADA St. George et al., The Holocene, 2010
- 28. GENERAL TENDENCY WITH MORE AND MORE EXCEPTIONS
- 29. QUESTION What is the seasonality of moisture-sensitive tree-ring records across North America?
- 31. 1747 The International Tree-Ring Databank houses ring-width chronologies from North America
- 32. QUESTION Are our analytical methods appropriate when we apply them to very large datasets?
- 33. COMMON ‘OPTIMAL’ PATTERNS PREDICTORS
- 35. “ This method of selecting proxies by screening a potentially large number of candidates for positive correlations runs the danger of choosing a proxy by chance. Gerd Bürger ” Science 2007
- 36. Carlo Emilio Bonferroni 1892 - 1960
- 39. 1747 RING-WIDTH 0.95 SIGNIFICANCE CHRONOLOGIES LEVEL
- 40. 1747 RING-WIDTH 0.95 ➔ SIGNIFICANCE 87 CHRONOLOGIES CHRONOLOGIES LEVEL THAT CORRELATE WITH JUST ABOUT ANYTHING
- 41. 2 approaches that might help
- 42. 1 We should test our models against noise.
- 43. Decadal ‘hotspots’ in winter precipitation 0% 10% 20% 30% variance Ault and St. George, Journal of Climate, 2010
- 45. tree-ring width records International Tree-Ring Databank St. George and Ault, JGR-A, 2011
- 46. Carlo Emilio Bonferroni 1892 - 1960
- 48. decadal target decadal ‘noise’ St. George and Ault, JGR-A, 2011
- 49. 2 We need to use all the data we have.
- 51. QUESTION the entire set of What is the seasonality of moisture-sensitive tree-ring records across North America?