Persistent Link:
http://hdl.handle.net/10150/301558
Title:
North American Monsoon Paleoclimatology From Tree Rings
Author:
Griffin, Richard Daniel
Issue Date:
2013
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The North American monsoon is central to Southwestern climate and is a research focus in climatology. Of the various monsoon paleoclimate proxies, precisely dated and seasonally resolved tree-ring records offer unique opportunity for contextualizing modern instrumental observations and climate model projections. Focused on latewood, the dark-colored sub-annual component of conifer tree rings that forms in the late growing season, this dissertation research represents a systematic effort to diagnose the tree-growth response to monsoon climate, to develop a replicated network of monsoon-sensitive chronologies, and to characterize monsoon paleoclimate variability in the southwestern United States. A pilot study using latewood measurements from five locations assessed seasonal climate response sensitivity to various chronology development techniques. Results informed a protocol for chronology development, which was used to produce a unique network of 53 monsoon-sensitive latewood chronologies for the southwestern United States. A chronology subset was used to develop the first monsoon precipitation reconstruction for a large and important region of the southwestern United States and northwestern Mexico. This reconstruction revealed monsoon paleodroughts more persistent and extreme than any during the instrumental era and indicated that the southwestern decadal droughts of the last 470 years were characterized not just by cool-season precipitation deficits, but also by persistently dry monsoon conditions. The previously noted tendency for winter and summer precipitation to be out of phase was found to be unstable through time and anomalously strong during the recent instrumental era. The paleoclimatic significance of the new sub-annual chronology network was characterized in terms of chronology signal strength, climate response seasonality, and dominant spatiotemporal structure. With only a few exceptions, the latewood chronologies were found to contain monsoon-specific climate signal that was not available from previously existing records of annual tree-ring width. Principal components analysis revealed that the chronology network captures both temporal variability and spatial structure inherent to monsoon precipitation. As such, proxy data developed in this dissertation are unique are uniquely suited for studying spatiotemporal variability in monsoon paleoclimate. Outcomes from this dissertation are broadly relevant in environmental research and could potentially inform long-term strategies for adaptive management of natural resources.
Type:
text; Electronic Dissertation
Keywords:
dendroclimatology; Geography; American Southwest
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Geography
Degree Grantor:
University of Arizona
Advisor:
Woodhouse, Connie A.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleNorth American Monsoon Paleoclimatology From Tree Ringsen_US
dc.creatorGriffin, Richard Danielen_US
dc.contributor.authorGriffin, Richard Danielen_US
dc.date.issued2013-
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe North American monsoon is central to Southwestern climate and is a research focus in climatology. Of the various monsoon paleoclimate proxies, precisely dated and seasonally resolved tree-ring records offer unique opportunity for contextualizing modern instrumental observations and climate model projections. Focused on latewood, the dark-colored sub-annual component of conifer tree rings that forms in the late growing season, this dissertation research represents a systematic effort to diagnose the tree-growth response to monsoon climate, to develop a replicated network of monsoon-sensitive chronologies, and to characterize monsoon paleoclimate variability in the southwestern United States. A pilot study using latewood measurements from five locations assessed seasonal climate response sensitivity to various chronology development techniques. Results informed a protocol for chronology development, which was used to produce a unique network of 53 monsoon-sensitive latewood chronologies for the southwestern United States. A chronology subset was used to develop the first monsoon precipitation reconstruction for a large and important region of the southwestern United States and northwestern Mexico. This reconstruction revealed monsoon paleodroughts more persistent and extreme than any during the instrumental era and indicated that the southwestern decadal droughts of the last 470 years were characterized not just by cool-season precipitation deficits, but also by persistently dry monsoon conditions. The previously noted tendency for winter and summer precipitation to be out of phase was found to be unstable through time and anomalously strong during the recent instrumental era. The paleoclimatic significance of the new sub-annual chronology network was characterized in terms of chronology signal strength, climate response seasonality, and dominant spatiotemporal structure. With only a few exceptions, the latewood chronologies were found to contain monsoon-specific climate signal that was not available from previously existing records of annual tree-ring width. Principal components analysis revealed that the chronology network captures both temporal variability and spatial structure inherent to monsoon precipitation. As such, proxy data developed in this dissertation are unique are uniquely suited for studying spatiotemporal variability in monsoon paleoclimate. Outcomes from this dissertation are broadly relevant in environmental research and could potentially inform long-term strategies for adaptive management of natural resources.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectdendroclimatologyen_US
dc.subjectGeographyen_US
dc.subjectAmerican Southwesten_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineGeographyen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorWoodhouse, Connie A.en_US
dc.contributor.committeememberMeko, David M.en_US
dc.contributor.committeememberComrie, Andrew C.en_US
dc.contributor.committeememberJacobs, Katharine L.en_US
dc.contributor.committeememberWoodhouse, Connie A.en_US
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