Southern Hemisphere westerly wind changes during the Last Glacial Maximum: paleo-data synthesis
Southern Hemisphere westerly wind changes during the Last Glacial Maximum: paleo-data synthesis
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DOI：
10.1016/j.quascirev.2013.01.017
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发表时间：
2013-05-15
影响因子：
4
通讯作者：
Bopp, L.
中科院分区：
文献类型：
--
作者：
Kohfeld, K. E.;Graham, R. M.;Bopp, L.
末次冰河周期期间南半球西风强度和位置的变化被用来解释千禧年和冰期间冰期的气候波动。然而，古模型和古数据都没有就研究最多的冰期（末次盛冰期（LGM））与最近的过去相比风力强度和纬度变化的幅度或什至符号达成一致。本文综合了用于推断末次盛宴风变化的古环境数据。提供了陆地湿度、尘埃沉降、海面温度和海洋锋面以及海洋生产力变化的数据汇编，并对末次盛冰期南半球海洋环流变化的现有数据进行了总结。我们发现，末次盛行风和气候变化的任何假设都需要为大陆西海岸湿度增加、亚南极地区气温降低和生产力提高以及南部非洲周围厄加勒斯泄漏减少提供合理的解释。我们的比较表明，风的整体加强、向赤道方向的位移或根本没有变化都可以被解释为与观测结果一致。如果为所有提供的证据寻找与南西风有关的单一原因，那么赤道方向的位移或风的加强将与最大比例的观测结果一致。然而，不能排除其他过程，例如风的减弱或向极地移动、水文循环减弱、海冰覆盖范围扩大以及浮力通量变化，作为观测到的湿度、表面温度和生产力变化的潜在解释。我们认为，仅根据数据重建来解决末次盛冰期期间西风的位置和强度仍然难以实现。然而，我们相信这些环境条件的数据重建可以与模型模拟结合使用，以确定哪些过程最能代表末次盛宴期间的西风条件。 Crown 版权所有 (C) 2013 由 Elsevier Ltd 出版。保留所有权利。
Changes in the strength and position of Southern Hemisphere westerly winds during the Last Glacial cycle have been invoked to explain both millennial and glacial interglacial climate fluctuations. However, neither paleo models nor paleodata agree on the magnitude, or even the sign, of the change in wind strength and latitude during the most studied glacial period, the Last Glacial Maximum (LGM), compared to the recent past. This paper synthesizes paleo-environmental data that have been used to infer changes in LGM winds. Data compilations are provided for changes in terrestrial moisture, dust deposition, sea surface temperatures and ocean fronts, and ocean productivity, and existing data on Southern Hemisphere ocean circulation changes during the LGM are summarized. We find that any hypothesis of LGM wind and climate change needs to provide a plausible explanation for increased moisture on the west coast of continents, cooler temperatures and higher productivity in the Subantarctic Zone, and reductions in Agulhas leakage around southern Africa. Our comparison suggests that an overall strengthening, an equatorward displacement, or no change at all in winds could all be interpreted as consistent with observations. If a single cause related to the southern westerlies is sought for all the evidence presented, then an equatorward displacement or strengthening of the winds would be consistent with the largest proportion of the observations. However, other processes, such as weakening or poleward shifts in winds, a weakened hydrological cycle, extended sea-ice cover, and changed buoyancy fluxes, cannot be ruled out as potential explanations of observed changes in moisture, surface temperature, and productivity. We contend that resolving the position and strength of westerly winds during the LGM remains elusive based on data reconstructions alone. However, we believe that these data reconstructions of environmental conditions can be used in conjunction with model simulations to identify which processes best represent westerly wind conditions during the LGM. Crown Copyright (C) 2013 Published by Elsevier Ltd. All rights reserved.