San Francisco Peaks.
U.S. Geological Survey photo. |
Reconstructed Temperature and Precipitation on a Millennial Timescale
from Tree-Rings in the Southern Colorado Plateau, U.S.A.
Climatic Change
Volume 70, Number 3, pp. 465 - 487, June 2005.
Matthew Salzer 1 and Kurt F. Kipfmueller 1,2
1Laboratory of Tree-Ring Research
The University of Arizona
Tucson, Arizona 85721, U.S.A.
2
Present address: Department of Geography
University of Minnesota
Minneapolis, MN 55455, U.S.A.
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ABSTRACT:
Two independent calibrated and verified climate reconstructions from
ecologically contrasting tree-ring sites in the southern Colorado Plateau,
U.S.A. reveal decadal-scale climatic trends during the past two millennia.
Combining precisely dated annual mean-maximum temperature and October
through July precipitation reconstructions yields an unparalleled record
of climatic variability. The approach allows for the identification of
thirty extreme wet periods and thirty-five extreme dry periods in the
1,425-year precipitation reconstruction and 30 extreme cool periods and
26 extreme warm periods in 2,262-year temperature reconstruction.
In addition, the reconstructions were integrated to identify intervals
when conditions were extreme in both climatic variables (cool/dry, cool/wet,
warm/dry, warm/wet). Noteworthy in the reconstructions are the post-1976
warm/wet period, unprecedented in the 1,425-year record both in amplitude
and duration, anomalous and prolonged late 20th century warmth, that while
never exceeded, was nearly equaled in magnitude for brief intervals in
the past, and substantial decadal-scale variability within the Medieval
Warm Period and Little Ice Age intervals.
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