Centennial-scale dynamics of the Southern Hemisphere Westerly Winds across the Drake Passage over the past two millennia
Centennial-scale dynamics of the Southern Hemisphere Westerly Winds across the Drake Passage over the past two millennia
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过去两千年来穿过德雷克海峡的南半球西风的百年尺度动态
作者：
Zhengyu Xia;Zicheng Yu;Zicheng Yu;J. Loisel
南半球西风对区域和全球气候有重要的控制作用。仪器和再分析记录表明，自世纪后期以来，SHWW带的加强和向极收缩。这种变化也对南大洋上升流和二氧化碳脱气有影响。因此，更好地了解近几十年来的长期SHWW行为和动态对于预测未来变化至关重要。在这里，我们应用同位素分析泥炭藓纤维素从泥炭沼泽在巴塔哥尼亚最南端（~54°S）重建降水的氧同位素组成（δ 18 O p）的变化，可以阐明过去的水分来源和轨迹的变化。我们解释了δ 18 O p的正移，表明较弱的SHWW和更重要的是，更频繁的东风流，增强了来自大西洋的水分供应。相反，δ 18 O p的负移表明更强的SHWW和安第斯雨影的加强。我们的数据，沿着与其他证据从最南端的巴塔哥尼亚和南极半岛，建议在百年尺度的变化在德雷克海峡的任何一方在过去的两千年，可能作为一个遥相关响应厄尔尼诺南方涛动样的变化。我们的研究意味着，过去的变化在SHWW和相关的遥相关机制的调查应考虑天气尺度的大气环流模式，而不是看到SHWW作为一个简单的西向东（纬向）风的流动模式，特别是在时间尺度上的SHWW表达纬向不对称的南大洋的不同部门之间。
The Southern Hemisphere Westerly Winds (SHWW) exert important controls on regional and global climate. Instrumental and reanalysis records indicate strengthening and poleward contraction of the SHWW belt since the late twentieth century. Such changes also have implications for Southern Ocean upwelling and CO 2 degassing. Therefore, a better understanding of the long-term SHWW behaviors and dynamics beyond recent decades is critical for projecting future changes. Here, we applied isotope analysis of Sphagnum moss cellulose from a peat bog in southernmost Patagonia (~54°S) to reconstruct changes in oxygen isotope composition of precipitation ( δ 18 O p ) that could elucidate past shifts in moisture sources and trajectories. We interpreted the positive shifts in δ 18 O p to indicate weaker SHWW and, impor-tantly, more frequent easterly flows that enhance moisture supply sourced from the Atlantic Ocean. In contrast, negative shifts in δ 18 O p indicate stronger SHWW and intensification of the Andean rain shadow. Our data, along with other evidence from southernmost Patagonia and the Antarctic Peninsula, suggest a coherent pattern of centennial-scale variability in SHWW strength on either side of the Drake Passage over the past two millennia, probably as a teleconnection response to El Niño–Southern Oscillation–like variability. Our study implies that investigations of past changes in the SHWW and associated teleconnection mechanisms should consider synoptic-scale atmospheric circulation patterns, rather than seeing SHWW as a simplistic west-to-east (zonal) wind-flow pattern, particularly on the time scales over which the SHWW express zonal asymmetry among different sectors of the Southern Ocean.
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影响因子：
4
作者：
N. Scroxton;S. Burns;D. McGee;B. Hardt;L. Godfrey;Lovasoa Ranivoharimanana;P. Faina
通讯作者：
N. Scroxton;S. Burns;D. McGee;B. Hardt;L. Godfrey;Lovasoa Ranivoharimanana;P. Faina
影响因子：
2.4
作者：
Loisel, Julie;Yu, Zicheng;Zhou, Weijian
通讯作者：
Zhou, Weijian
影响因子：
4
作者：
J. Quade;M. Kaplan
通讯作者：
J. Quade;M. Kaplan
影响因子：
18.3
作者：
Lamy, Frank;Kilian, Rolf;Steinke, Tatjana
通讯作者：
Steinke, Tatjana
利用南美南部泥炭地研究全新世晚期水文气候的变化和降水的稳定同位素组成：一个假设
影响因子：
4.3
作者：
Daley T
通讯作者：
Daley T