Triple oxygen and hydrogen isotopes of gypsum hydration water for quantitative paleo-humidity reconstruction
Triple oxygen and hydrogen isotopes of gypsum hydration water for quantitative paleo-humidity reconstruction
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DOI：
10.1016/j.epsl.2017.10.020
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发表时间：
2018-01-01
影响因子：
5.3
通讯作者：
Hodell, David A.
中科院分区：
文献类型：
--
作者：
Gazquez, Fernando;Morellon, Mario;Hodell, David A.
大气相对湿度是影响植被的一个重要参数，但古湿度代用指标缺乏且难以标定。在这里，我们使用三重氧（δ O-17和O-18）和氢（δ D）同位素的结构结合的石膏水化水（GHW）提取湖石膏量化过去的大气相对湿度的变化。蒸发同位素质量平衡模型与蒙特卡罗模拟一起使用，以确定同时满足GHW稳定同位素结果的气候条件范围，并具有统计上可靠的不确定性估计。我们应用这种方法来重建古水的同位素组成的埃斯塔尼娅湖（西班牙东北部）和归一化的大气相对湿度（RH）的变化。在末次冰期终止和全新世（从类似的15至0.6卡尔。同位素记录表明，最干燥的条件发生在新仙女木（YD;类似于12-13 cal. kyrs BP）。我们估计青年节期间的RHQ类似于40-45%，比今天低30-35%。由于极锋向南位移，接近42度N，它是在YD比Belling-Allered时期和全新世风和干燥。平均大气湿度从前寒带至全新世早期逐渐增加（类似于11至8 cal. kyrs BP，50-60%），达到70- 75%RH。从近似7.5卡BP直到今天。我们证明，结合氢和三重氧同位素GHW提供了一个强大的工具，定量估计过去的相对湿度的变化。(C)2017爱思唯尔B. V.保留所有权利。
Atmospheric relative humidity is an important parameter affecting vegetation yet paleo-humidity proxies are scarce and difficult to calibrate. Here we use triple oxygen (delta O-17 and O-18) and hydrogen (delta D) isotopes of structurally -bound gypsum hydration water (GHW) extracted from lacustrine gypsum to quantify past changes in atmospheric relative humidity. An evaporation isotope-mass-balance model is used together with Monte Carlo simulations to determine the range of climatological conditions that simultaneously satisfy the stable isotope results of GHW, and with statistically robust estimates of uncertainty. We apply this method to reconstruct the isotopic composition of paleo-waters of Lake Estanya (NE Spain) and changes in normalized atmospheric relative humidity (RH.) over the last glacial termination and Holocene (from similar to 15 to 0.6 cal. kyrs BP). The isotopic record indicates the driest conditions occurred during the Younger Dryas (YD; similar to 12-13 cal. kyrs BP). We estimate a RHQ of similar to 40-45% during the YD, which is similar to 30-35% lower than today. Because of the southward displacement of the Polar Front to similar to 42 degrees N, it was both windier and drier during the YD than the Belling-Allered period and Holocene. Mean atmospheric moisture gradually increased from the Preboreal to Early Holocene (similar to 11 to 8 cal. kyrs BP, 50-60%), reaching 70-75% RH. from similar to 7.5 cal. kyrs BP until present-day. We demonstrate that combining hydrogen and triple oxygen isotopes in GHW provides a powerful tool for quantitative estimates of past changes in relative humidity. (C) 2017 Elsevier B.V. All rights reserved.