A GCM‐based analysis of circulation controls on δ18O in the southwest Yukon, Canada: Implications for climate reconstructions in the region
A GCM‐based analysis of circulation controls on δ18O in the southwest Yukon, Canada: Implications for climate reconstructions in the region
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DOI：
10.1029/2009gl041408
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发表时间：
2010-03
影响因子：
5.2
通讯作者：
R. Field;G. Moore;G. Holdsworth;G. Schmidt
中科院分区：
文献类型：
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作者：
R. Field;G. Moore;G. Holdsworth;G. Schmidt
为了提高我们对育空地区西南部古气候记录的理解，我们使用配备同位素的大气环流模式（GCM）检查了对降水δ 18 O的控制。我们的研究结果表明，特别是在冷季，高δ 18 O与更深的阿留申低压和更强的偏南水汽流有关，而低δ 18 O与相反的气象条件有关。这些结果表明，世纪中期，该地区古气候记录中的δ 18 O值向较低方向的大幅转变与阿留申低压向较弱方向的转变有关。虽然不同意以前对这种转变的解释，但它与同期冰川前进和树木年轮生长的记录以及阿留申低压对该地区温度和降水的观测研究是一致的。
To improve our understanding of paleoclimatic records in the southwest Yukon, we examined controls on precipitation δ18O using an isotopically‐equipped atmospheric general circulation model (GCM). Our results show that, particularly during the cool‐season, elevated δ18O is associated with a deeper Aleutian Low and stronger southerly moisture flow, while lower δ18O is associated with the opposite meteorological conditions. These results suggest that the large mid‐19th century shift towards lower δ18O 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.