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A GCM‐based analysis of circulation controls on δ 18 O in the southwest Yukon, Canada: Implications for climate reconstructions in the region
Author(s) -
Field Robert D.,
Moore G. W. K.,
Holdsworth Gerald,
Schmidt Gavin A.
Publication year - 2010
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2009gl041408
Subject(s) - paleoclimatology , precipitation , climatology , gcm transcription factors , geology , atmospheric circulation , general circulation model , glacial period , climate change , period (music) , atmospheric sciences , geography , meteorology , oceanography , geomorphology , physics , acoustics
To improve our understanding of paleoclimatic records in the southwest Yukon, we examined controls on precipitation δ 18 O using an isotopically‐equipped atmospheric general circulation model (GCM). Our results show that, particularly during the cool‐season, elevated δ 18 O is associated with a deeper Aleutian Low and stronger southerly moisture flow, while lower δ 18 O is associated with the opposite meteorological conditions. These results suggest that the large mid‐19th century shift towards lower δ 18 O values seen in paleoclimate records from the region was associated with a shift towards a weaker Aleutian Low. While in disagreement with a previous interpretation of this shift, it is consistent with records of glacial advance and tree‐ring growth during the same period, and observational studies of Aleutian Low controls on temperature and precipitation in the region.