Attributing the U.S. Southwest's Recent Shift Into Drier Conditions
Attributing the U.S. Southwest's Recent Shift Into Drier Conditions
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DOI：
10.1029/2018gl078312
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发表时间：
2018-06
影响因子：
5.2
通讯作者：
F. Lehner;C. Deser;I. Simpson;L. Terray
中科院分区：
文献类型：
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作者：
F. Lehner;C. Deser;I. Simpson;L. Terray
美国西南部从20世纪80年代到2010年代经历了强烈的水文气候趋势，从凉爽潮湿到温暖干燥的条件。由于内部变化的影响，这一趋势的归因具有挑战性，但水资源管理者渴望在这个缺水地区规划强有力的气候变化信号。在这里，我们使用的经验方法的基础上构建的环流模拟评估大气环流变率的贡献，最近观察到的水文气候趋势。与其他研究一致，我们发现从1983年到2012年观测到的降水趋势主要是由于内部大气环流的变化，部分是由十年尺度的热带太平洋海面温度变化驱动的。去除这一内部动力学成分使观测到的降水趋势与气候模式中的气候强迫响应更加一致，表明在气候变化归因的综合视角方面取得了进展。
The U.S. Southwest experienced a strong hydroclimate trend from the 1980s to the 2010s, from cool and wet to warm and dry conditions. Attribution of this trend is challenging due to the influence of internal variability but desired by water managers eager to plan for robust signals of climate change in this water‐scarce region. Here we use an empirical method based on constructed circulation analogues to assess the contribution of atmospheric circulation variability to the recent observed hydroclimate trend. Consistent with other studies, we find the observed precipitation trend from 1983 to 2012 to be mainly due to internal atmospheric circulation variability that is driven in part by decadal‐scale tropical Pacific sea surface temperature changes. Removing this internal dynamical component brings the observed precipitation trend into closer agreement with the anthropogenically forced response in climate models, demonstrating progress toward an integrated perspective on climate change attribution.