Patterns and sources of multidecadal oscillations in droughtsensitive tree-ring records from the central and southern Rocky Mountains
Tree-ring records spanning the past seven centuries from the central and southern Rocky Mountains were studied using wavelet analysis to examine multidecadal (>30-70 yr) patterns of drought variation. Fifteen tree-ring series were grouped into five regional composite chronologies based on shared...
| Main Authors: | , , , |
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| Other Authors: | |
| Format: | Text |
| Language: | English |
| Published: |
2003
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| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.524.7005 http://www.fws.gov/bhg/PDFs/Gray et al.pdf |
| Summary: | Tree-ring records spanning the past seven centuries from the central and southern Rocky Mountains were studied using wavelet analysis to examine multidecadal (>30-70 yr) patterns of drought variation. Fifteen tree-ring series were grouped into five regional composite chronologies based on shared low-frequency behavior. Strong multidecadal phasing of moisture variation was present in all five regions during the late 16th century megadrought. Consistent oscillatory modes in the 30-60 yr domain persisted until the mid-19th century in two of the five regions, and wet-dry cycles were apparently synchronous at some sites until the 1950s drought. The 16th/17th century pattern of severe multidecadal drought followed by decades of unusually wet conditions resembles the 1950s drought and post-1976 wet period. The 16th century megadrought, which may have resulted from coupling of a decadal (~20-30 yr) Pacific cool phase with a multidecadal warm phase in the subtropical North Atlantic, marked a substantial |
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