Three hundred years of snowpack variability in southwestern British Columbia reconstructed from tree‐rings
Three hundred years of snowpack variability in southwestern British Columbia reconstructed from tree‐rings
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DOI：
10.1002/hyp.13933
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发表时间：
2020-10
影响因子：
3.2
通讯作者：
Bryan J. Mood;Bethany L Coulthard;Dan Smith
中科院分区：
文献类型：
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作者：
Bryan J. Mood;Bethany L Coulthard;Dan Smith
最近加拿大不列颠哥伦比亚省(BC)西南部的雪旱减少了春末和夏季典型干旱月份的季节性径流，导致社会经济和生态影响，引起人们对气候变化即将到来的后果的关注。关于该地区每年冬季降雪量变化的知识很大程度上来自一个稀疏的短期(≤50年)积雪观测站网络。在这篇文章中，我们开发了一个每年4月1日雪水当量(SWE)的重建，从活的树木年轮提供了一个长期的自然积雪变化的视角。树状水文模型估计，不列颠哥伦比亚省西南部地区4月1日的第一主成分SWE为1711。频谱分析确定了仪器前时期4月1日SWE的主要年代际变化。重建成功地捕捉到了已知的拉尼娜振荡对重建的SWE的仪器周期的影响，表明我们基于树轮的重建有可能为仪器前的海洋-大气与卑诗省西南部积雪动力学的联系提供见解。RUN分析表明，仪器前的雪旱持续时间和严重程度都是观测期间的两倍多，这表明仪器记录可能无法捕捉到4月1日SWE变化的全部范围。该重建提供了过去300年来公元前西南部SWE的第一个高分辨率描述，并可立即用于区域水资源管理者。
Recent snow droughts in southwestern British Columbia (BC), Canada, have reduced seasonal streamflow during the typically dry late‐spring and summer months, leading to socio‐economic and ecological impacts that draw attention to the impending consequences of climate change. Knowledge of annual winter snowfall variability within this region is largely derived from a sparse network of short‐duration (≤50 years) snow survey stations. In this paper, we develop an annual April 1 snow water equivalent (SWE) reconstruction from living tree‐ring chronologies that offer a perspective on long‐term natural snowpack variability. The dendrohydrological model estimates the first principal component April 1 SWE for the southwestern regions of BC to 1711. Spectral analysis identified dominant multidecadal April 1 SWE variability over the pre‐instrumental period. The reconstruction successfully captures known instrumental period influences of La Niña oscillations on reconstructed SWE, suggesting that our tree‐ring based the reconstruction has the potential to provide insights on pre‐instrumental ocean–atmosphere links with southwestern BC snowpack dynamics. Runs analysis suggests pre‐instrumental snow droughts have been more than twice as long in duration and severity than during the observed period which indicates the instrumental record may not capture the full range of April 1 SWE variability. The reconstruction provides the first high‐resolution description of SWE over the past 300 years in southwestern BC and is of immediate use to regional water resource managers.