TY - JOUR
T1 - Teleconnected ocean forcing of Western North American droughts and pluvials during the last millennium
AU - Routson, Cody C.
AU - Woodhouse, Connie A.
AU - Overpeck, Jonathan T.
AU - Betancourt, Julio L.
AU - McKay, Nicholas P.
N1 - Funding Information: We thank the National Oceanic and Atmospheric Administration (NOAA, NA11OAR4310162 ), the National Science Foundation ( AGS1243125 ), the Science Foundation Arizona Bisgrove Scholars Fellowship program ( BSP 0544-13 ), the NOAA funded Climate Assessment for the Southwest, the University of Arizona Department of Geoscience, and the Northern Arizona University School of Earth Science and Environmental Sustainability for contributing funding and support for this research. We also thank reviewers Dr. Gregory McCabe and two anonymous reviewers for their time, insights, and feedback. Publisher Copyright: © 2016 Elsevier Ltd
PY - 2016/8/15
Y1 - 2016/8/15
N2 - Western North America (WNA) is rich in hydroclimate reconstructions, yet questions remain about the causes of decadal-to-multidecadal hydroclimate variability. Teleconnection patterns preserved in annually-resolved tree-ring reconstructed drought maps, and anomalies in a global network of proxy sea surface temperature (SST) reconstructions, were used to reassess the evidence linking ocean forcing to WNA hydroclimate variability over the past millennium. Potential forcing mechanisms of the Medieval Climate Anomaly (MCA) and individual drought and pluvial events—including two multidecadal-length MCA pluvials—were evaluated. We show strong teleconnection patterns occurred during the driest (wettest) years within persistent droughts (pluvials), implicating SSTs as a potent hydroclimate forcing mechanism. The role of the SSTs on longer timescales is more complex. Pacific teleconnection patterns show little long-term change, whereas low-resolution SST reconstructions vary over decades to centuries. While weaker than the tropical Pacific teleconnections, North Atlantic teleconnection patterns and SST reconstructions also show links to WNA droughts and pluvials, and may in part account for longer-term WNA hydroclimate changes. Nonetheless, evidence linking WNA hydroclimate to SSTs still remains sparse and nuanced—especially over long-timescales with a broader range of hydroclimatic variability than characterized during the 20th century.
AB - Western North America (WNA) is rich in hydroclimate reconstructions, yet questions remain about the causes of decadal-to-multidecadal hydroclimate variability. Teleconnection patterns preserved in annually-resolved tree-ring reconstructed drought maps, and anomalies in a global network of proxy sea surface temperature (SST) reconstructions, were used to reassess the evidence linking ocean forcing to WNA hydroclimate variability over the past millennium. Potential forcing mechanisms of the Medieval Climate Anomaly (MCA) and individual drought and pluvial events—including two multidecadal-length MCA pluvials—were evaluated. We show strong teleconnection patterns occurred during the driest (wettest) years within persistent droughts (pluvials), implicating SSTs as a potent hydroclimate forcing mechanism. The role of the SSTs on longer timescales is more complex. Pacific teleconnection patterns show little long-term change, whereas low-resolution SST reconstructions vary over decades to centuries. While weaker than the tropical Pacific teleconnections, North Atlantic teleconnection patterns and SST reconstructions also show links to WNA droughts and pluvials, and may in part account for longer-term WNA hydroclimate changes. Nonetheless, evidence linking WNA hydroclimate to SSTs still remains sparse and nuanced—especially over long-timescales with a broader range of hydroclimatic variability than characterized during the 20th century.
KW - Climate change
KW - Drought
KW - Multi-proxy
KW - Pluvial
KW - Synthesis
KW - Western North America
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U2 - 10.1016/j.quascirev.2016.06.017
DO - 10.1016/j.quascirev.2016.06.017
M3 - Article
SN - 0277-3791
VL - 146
SP - 238
EP - 250
JO - Quaternary Science Reviews
JF - Quaternary Science Reviews
ER -