A mechanistic understanding of oxygen isotopic changes in the Western United States at the Last Glacial Maximum
A mechanistic understanding of oxygen isotopic changes in the Western United States at the Last Glacial Maximum
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对末次盛冰期美国西部氧同位素变化的机制理解
DOI：
10.1016/j.quascirev.2021.107255
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发表时间：
2021
影响因子：
4
通讯作者：
Liu, Zhengyu
中科院分区：
文献类型：
--
作者：
Tabor, Clay;Lofverstrom, Marcus;Oster, Jessica;Wortham, Barbara;de Wet, Cameron;Montañez, Isabel;Rhoades, Alan;Zarzycki, Colin;He, Chengfei;Liu, Zhengyu
在末次盛冰期（LGM），记录表明，相对于现在，美国西北部的条件更干燥，美国西南部的条件更潮湿，水的同位素组成也发生了广泛的变化。然而，导致这些变化的机制仍然不明确。在这里，我们探讨在美国西部的LGM和工业化前的水同位素示踪剂启用地球系统模型之间的水文气候的差异。然后，我们使用代理前向模型比较模拟和记录的洞穴沉积物中的δ 18 O。我们发现，在美国西部的水文气候响应的模式在LGM涉及到1）北太平洋的频率增加和南移的冬季热带气旋，2）更大的降雨量的水分，因为它在大陆上移动，和3）减少蒸发在较冷的LGM气候的组合。模拟的末次盛冰期降水δ 18 O值较低主要与冷季除湿效率的提高有关，其次是冷季降水相对较多。地表温度和北美冰盖都对LGM的水文气候变化做出了贡献。对比代用正演模型和美国西部洞穴沉积物记录得到的δ 18 O，在末次盛冰期显示出普遍的一致性，随着向大陆内部逐渐减少。这项研究突出了LGM水文和δ18O变化之间的相似性和差异，并强调了模型替代比较的解释效用。
At the Last Glacial Maximum (LGM), records suggest drier conditions in the northwest United States and wetter conditions in the southwest United States relative to present-day as well as widespread changes in the isotopic composition of water. However, the mechanisms responsible for these changes remain ambiguous. Here, we explore differences in western United States hydroclimate between the LGM and preindustrial with a water isotope tracer enabled Earth System Model. We then use proxy forward models to compare simulated and recorded δ18O in speleothems. We find that the pattern of hydroclimate response in the western United States at the LGM relates to a combination of 1) increased frequency and southward shifted wintertime extratropical cyclones in the North Pacific, 2) greater rainout of moisture as it moves over the continent, and 3) reduced evaporation in the cooler LGM climate. The simulated lower δ18O of precipitation at the LGM relates predominantly to an increase in cool season moisture removal efficiency, with a secondary contribution from relatively more cool season precipitation. Both surface temperatures and North American ice sheets contribute to these hydroclimate changes at the LGM. Comparisons between δ18O from proxy forward models and speleothem records in the western United States show general agreement at the LGM, with increasing depletion moving towards the continental interior. This study highlights the similarities and differences between hydrologic and δ18O changes at the LGM and emphasizes the utility of model-proxy comparison for interpretation.
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DOI：
10.1029/2019jd030936
发表时间：
2019-12
期刊：
Journal of Geophysical Research: Atmospheres
影响因子：
--
作者：
J. Rutz;C. Shields;J. Lora;A. Payne;B. Guan;P. Ullrich;T. O’Brien;L. Leung;F. Ralph;M. Wehner;S. Brands;A. Collow;N. Goldenson;I. Gorodetskaya;Helen V. Griffith;K. Kashinath;B. Kawzenuk;Harinarayan Krishnan;V. Kurlin;D. Lavers;G. Magnusdottir;K. Mahoney;E. McClenny;G. Muszynski;P. Nguyen;M. Prabhat;Y. Qian;A. Ramos;C. Sarangi;S. Sellars;T. Shulgina;R. Tomé;D. Waliser;D. Walton;G. Wick;Anna M. Wilson;M. Viale
通讯作者：
J. Rutz;C. Shields;J. Lora;A. Payne;B. Guan;P. Ullrich;T. O’Brien;L. Leung;F. Ralph;M. Wehner;S. Brands;A. Collow;N. Goldenson;I. Gorodetskaya;Helen V. Griffith;K. Kashinath;B. Kawzenuk;Harinarayan Krishnan;V. Kurlin;D. Lavers;G. Magnusdottir;K. Mahoney;E. McClenny;G. Muszynski;P. Nguyen;M. Prabhat;Y. Qian;A. Ramos;C. Sarangi;S. Sellars;T. Shulgina;R. Tomé;D. Waliser;D. Walton;G. Wick;Anna M. Wilson;M. Viale
变暖对美国西部登陆大气河流及其洪水破坏的影响
DOI：
--
发表时间：
2021
期刊：
影响因子：
--
作者：
Alan Michael Rhoades;M. Risser;D. Stone;M. Wehner;Andrew D. Jones
通讯作者：
Andrew D. Jones
影响因子：
6.8
作者：
Brady, E.;Stevenson, S.;Zhu, J.
通讯作者：
Zhu, J.
影响因子：
5.3
作者：
C. Skinner;J. Lora;A. Payne;C. Poulsen
通讯作者：
C. Skinner;J. Lora;A. Payne;C. Poulsen
大气河检测的共识和分歧：ARTMIP 全球目录
影响因子：
5.2
作者：
J. Lora;C. Shields;J. Rutz
通讯作者：
J. Rutz