North American Monsoon Variability from Paleoclimate Era to Climate Change Projection: A Multiple Dataset Perspective

Persistent Link:
http://hdl.handle.net/10150/338900
Title:
North American Monsoon Variability from Paleoclimate Era to Climate Change Projection: A Multiple Dataset Perspective
Author:
Carrillo Cruz, Carlos Mauricio
Issue Date:
2014
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:
In the southwestern United States, the North American monsoon (NAM) is the main driver of severe weather and accounts for nearly half the annual precipitation. How the monsoon has behaved in the past and how it will change in the future is a question of major importance for natural resource management and infrastructural planning. In this dissertation, I present the results of three studies that have investigated North American monsoon variability and change from the perspective of paleoclimate records, future climate change projections, and simulation of the low-frequency variability with the longest retrospective atmospheric reanalysis. In the first study, a monsoon-sensitive network of tree-ring chronologies is evaluated within its ability to reproduce NAM variability during the past four centuries. Matrix methods are used to detect the low-frequency spatiotemporal variability. The treering chronologies can reasonable characterizes the dominant modes of NAM climate variability. The monsoon tree-ring network is able to reproduce the interannual variability of cool and warm season precipitation, in a manner similar to the period of the instrumental record. Earlywood and latewood adjusted chronologies reveal low frequency climate variability at decadal and longer timescales that is beyond the ability of the instrumental record to temporally well resolve. This low-frequency climate variability seems to be part of a much larger cycle that coincides with the occurrence of multiyear persistent droughts. In the second study, we consider the modes of natural climate variability identified in the previous study to objectively assess the degree of physical uncertainty in climate change projections for NAM from Regional Climate Models (RCMs) used in the North American Regional Climate Change Assessment Program (NARCCAP). Climate change projection models are evaluated mainly on their ability to represent warm season driven by quasi-stationary Rossby wave trains and El Niño Southern Oscillation – Pacific Decadal Variability (ENSO-PDV). It is concluded that use of the NARCCAP model ensemble mean for NAM climate projections is probably not suitable. NARCCAP RCMs are largely a slave to their driving global models and their error in the specification of large-scale atmospheric circulation. Only one out of eight NARCCAP RCMs has a reasonable representation of the seasonal cycle of monsoon precipitation and ENSOdriven interannual variability in both the 20th and 21st centuries. No decadal variability was observed in any of the NARCCAP RCMs. In the third study, the low-frequency drought signal found with tree-ring chronologies is further explored within the framework of a regional climate modeling. Version 2 of the Twentieth-Century Reanalysis (DD-20CR) is dynamically downscaled over a contiguous U.S.-Mexico domain. Statistic analysis of the DD-20CR suggests that the low-frequency drought signal in the Southwest is driven by atmospheric circulation changes on global to continental scales that affect precipitation in Central American as well. DD-20CR reproduces the spatial patterns of precipitation associated with climate variability at decadal and longer timescales in a manner that compares well with observational records and tree-ring chronologies. Low-frequency climate variability is therefore likely responsible for the multiyear persistent droughts in the last four centuries, as independently evaluated from the tree-ring monsoon-sensitive network.
Type:
text; Electronic Dissertation
Keywords:
Low-frequency variability; NARCCAP; North American monsoon; Paleoclimate; Tree-ring chronologies; Climate change; Atmospheric Sciences
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Atmospheric Sciences
Degree Grantor:
University of Arizona
Advisor:
Castro, Christopher L.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen
dc.titleNorth American Monsoon Variability from Paleoclimate Era to Climate Change Projection: A Multiple Dataset Perspectiveen_US
dc.creatorCarrillo Cruz, Carlos Mauricioen_US
dc.contributor.authorCarrillo Cruz, Carlos Mauricioen_US
dc.date.issued2014-
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.abstractIn the southwestern United States, the North American monsoon (NAM) is the main driver of severe weather and accounts for nearly half the annual precipitation. How the monsoon has behaved in the past and how it will change in the future is a question of major importance for natural resource management and infrastructural planning. In this dissertation, I present the results of three studies that have investigated North American monsoon variability and change from the perspective of paleoclimate records, future climate change projections, and simulation of the low-frequency variability with the longest retrospective atmospheric reanalysis. In the first study, a monsoon-sensitive network of tree-ring chronologies is evaluated within its ability to reproduce NAM variability during the past four centuries. Matrix methods are used to detect the low-frequency spatiotemporal variability. The treering chronologies can reasonable characterizes the dominant modes of NAM climate variability. The monsoon tree-ring network is able to reproduce the interannual variability of cool and warm season precipitation, in a manner similar to the period of the instrumental record. Earlywood and latewood adjusted chronologies reveal low frequency climate variability at decadal and longer timescales that is beyond the ability of the instrumental record to temporally well resolve. This low-frequency climate variability seems to be part of a much larger cycle that coincides with the occurrence of multiyear persistent droughts. In the second study, we consider the modes of natural climate variability identified in the previous study to objectively assess the degree of physical uncertainty in climate change projections for NAM from Regional Climate Models (RCMs) used in the North American Regional Climate Change Assessment Program (NARCCAP). Climate change projection models are evaluated mainly on their ability to represent warm season driven by quasi-stationary Rossby wave trains and El Niño Southern Oscillation – Pacific Decadal Variability (ENSO-PDV). It is concluded that use of the NARCCAP model ensemble mean for NAM climate projections is probably not suitable. NARCCAP RCMs are largely a slave to their driving global models and their error in the specification of large-scale atmospheric circulation. Only one out of eight NARCCAP RCMs has a reasonable representation of the seasonal cycle of monsoon precipitation and ENSOdriven interannual variability in both the 20th and 21st centuries. No decadal variability was observed in any of the NARCCAP RCMs. In the third study, the low-frequency drought signal found with tree-ring chronologies is further explored within the framework of a regional climate modeling. Version 2 of the Twentieth-Century Reanalysis (DD-20CR) is dynamically downscaled over a contiguous U.S.-Mexico domain. Statistic analysis of the DD-20CR suggests that the low-frequency drought signal in the Southwest is driven by atmospheric circulation changes on global to continental scales that affect precipitation in Central American as well. DD-20CR reproduces the spatial patterns of precipitation associated with climate variability at decadal and longer timescales in a manner that compares well with observational records and tree-ring chronologies. Low-frequency climate variability is therefore likely responsible for the multiyear persistent droughts in the last four centuries, as independently evaluated from the tree-ring monsoon-sensitive network.en_US
dc.typetexten
dc.typeElectronic Dissertationen
dc.subjectLow-frequency variabilityen_US
dc.subjectNARCCAPen_US
dc.subjectNorth American monsoonen_US
dc.subjectPaleoclimateen_US
dc.subjectTree-ring chronologiesen_US
dc.subjectClimate changeen_US
dc.subjectAtmospheric Sciencesen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineAtmospheric Sciencesen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorCastro, Christopher L.en_US
dc.contributor.committeememberCastro, Christopher L.en_US
dc.contributor.committeememberWoodhouse, Connie A.en_US
dc.contributor.committeememberGarfin, Greggen_US
dc.contributor.committeememberDominguez, Francinaen_US
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