Wind-driven evolution of the North Pacific subpolar gyre over the last deglaciation
Wind-driven evolution of the North Pacific subpolar gyre over the last deglaciation
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末次冰消期北太平洋副极地环流的风驱动演化
DOI：
10.1002/essoar.10501158.1
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Gray W
中科院分区：
文献类型：
--
作者：
Gray W
北太平洋大气和海洋环流是我们理解自上次冰盛期(LGM)以来全球气候系统重组的关键缺失部分。这里，使用整个盆地的浮游有孔虫δ18O的汇编，我们表明在末次盛冰期，北太平洋亚极涡旋向南延伸了约3度，这与海表面温度和生产力替代数据一致。对一系列气候模式的分析表明，亚极地涡旋的扩大与实质上的涡旋加强有关。这些环流变化是由中纬度西风带南移和极地东风带风应力增加所驱动的。使用单强迫模式运行，我们表明这些大气环流变化是对Laurentide冰盖的地形和反照率综合效应的非线性响应。我们的重建表明，在海因里希阶梯1期间，涡旋边界(因此西风)在~17-16ka开始向北迁移。
North Pacific atmospheric and oceanic circulations are key missing pieces in our understanding of the reorganisation of the global climate system since the Last Glacial Maximum (LGM). Here, using a basin-wide compilation of planktic foraminiferal δ18O, we show that the North Pacific subpolar gyre extended ~3 degrees further south during the LGM, consistent with sea surface temperature and productivity proxy data. Analysis of an ensemble of climate models indicates that the expansion of the subpolar gyre was associated with a substantial gyre strengthening. These gyre circulation changes were driven by a southward shift in the mid-latitude westerlies and increased wind-stress from the polar easterlies. Using single-forcing model runs, we show these atmospheric circulation changes are a non-linear response to the combined topographic and albedo effects of the Laurentide Ice Sheet. Our reconstruction suggests the gyre boundary (and thus westerly winds) began to migrate northward at ~17-16 ka, during Heinrich Stadial 1.