Biomarkers reveal abrupt switches in hydroclimate during the last glacial in southern California
Biomarkers reveal abrupt switches in hydroclimate during the last glacial in southern California
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生物标记揭示了南加州末次冰河期间水文气候的突然变化
DOI：
10.1016/j.epsl.2019.03.024
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发表时间：
2019
影响因子：
5.3
通讯作者：
Tierney, Jessica E.
中科院分区：
文献类型：
--
作者：
Feakins, Sarah J.;Wu, Mong Sin;Ponton, Camilo;Tierney, Jessica E.
恢复过去的水气候提供了一种手段，可以了解降水对全球海洋-大气气候动态的响应，超出了仪器记录的范围。晚期冰川气候的特点是冰和海洋动力学的突然变化，但对水气候的影响并不是那么广为人知。在这里，我们提供了基于植物叶蜡氢同位素组成(δD WAX)的降水同位素的有机地球化学替代证据和基于支链甘油二烷基甘油四醚(BrGDGTS)的温度替代证据，这些支链甘油二烷基甘油四醚(BrGDGTS)来自细菌的膜脂，每个细菌膜脂提取自加利福尼亚州埃尔西诺湖跨越32-9ka的沉积档案。我们添加了来自其他生物标志物分析的植被和盐度的替代证据，并与来自同一岩心的先前的花粉和沉积学证据进行了比较。我们的记录表明，埃尔西诺湖在经历了一个以C3为主的冷湿阶段(20-14.5ka)后，出现了10℃的强烈降冰期变暖(从14.5ka开始)，伴随着+90‰的降水和更多的C4植被(12-10ka)的D-富集期，表明在最后一次冰盛期和Heinrich Staial 1期间，降水以冬季为主。在晚冰期(32-20ka)，我们发现了突然的变率，降水同位素位移(∼70‰)与温度波动无关，这意味着风暴路径的变化，而不是当地温度作为降水同位素信号的驱动因素。然而，温度与水文气候并非没有关系：我们发现极端温暖的温度为29.4ka和26.8ka，后者与现有报告中延长的干旱期(27.5-25.5ka)相吻合，这表明在通常较凉爽的冰川期存在较长的炎热和干燥间歇期。我们比较了δD蜡和来自内华达州的洞穴δ18 O，也在冬季占主导地位的降水区。我们的结果证实了末次冰期最大值和去冰期信号，并填补了揭示32-20ka风暴路径不稳定的空白，但生物标志物信号的步调和强度值得谨慎解释。
Reconstructions of past hydroclimate provide a means to understand precipitation responses to global ocean-atmosphere climate dynamics beyond the scope of that in the instrumental record. Late glacial climate was characterized by abrupt variability in ice and ocean dynamics, however the implications for hydroclimate are not as well known. Here we present organic geochemical proxy evidence for precipitation isotopes based on plant leaf wax hydrogen isotopic compositions (δD wax) and temperature proxy evidence based upon the branched glycerol dialkyl glycerol tetraethers (brGDGTs), that derive from the membrane lipids of bacteria, each extracted from a sedimentary archive in Lake Elsinore, California spanning 32–9 ka. We add proxy evidence for vegetation and salinity from additional biomarker analyses and compare to prior pollen and sedimentological evidence from the same core. Our record indicates a strong deglacial warming of 10° C in Lake Elsinore (beginning at 14.5 ka) that accompanied a D-enrichment of precipitation of+ 90‰ and more C 4 vegetation (12–10 ka), after a cold, wet and C 3-dominated phase (20–14.5 ka), indicating winter-dominated precipitation during the Last Glacial Maximum and Heinrich Stadial 1. During the late glacial (32–20 ka) we find abrupt variability, with precipitation isotopic shifts (∼ 70‰) that are independent of temperature swings implicating changes in storm track, rather than local temperature as drivers of the precipitation isotope signal. Temperature is however not irrelevant for hydroclimate: we find extreme warmth at 29.4 ka and 26.8 ka, the latter coincident with existing reports of an extended dry period (27.5–25.5 ka), suggesting a long hot and dry interlude during the generally cooler glacial period. We compare δD wax with speleothem δ 18 O from Nevada, also within the winter-dominated precipitation region. Our results corroborate the Last Glacial Maximum and deglacial signals, and fill gaps revealing storm-track instability from 32–20 ka, however the pacing and magnitude of the biomarker signals merit cautious interpretation.
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影响因子：
4
作者：
M. Kirby;S. Feakins;Nicole Bonuso;Joanna M. Fantozzi;C. Hiner
通讯作者：
M. Kirby;S. Feakins;Nicole Bonuso;Joanna M. Fantozzi;C. Hiner
区域同位素效应及其在加利福尼亚州西南部水文调查中的应用
影响因子：
5.4
作者：
Alan E. Williams;Daniel P. Rodoni
通讯作者：
Daniel P. Rodoni
18岁的成年人需要什么样的消费者教育？
DOI：
--
发表时间：
2022
期刊：
影响因子：
--
作者：
広瀬浩二郎;山本容子;庄司佳子・小林知子・奥西麻衣子・河原佑香・柿野成美
通讯作者：
庄司佳子・小林知子・奥西麻衣子・河原佑香・柿野成美
东北太平洋海面温度和海洋环流的千年尺度变化，10-60 kyr BP
DOI：
--
发表时间：
2012
期刊：
影响因子：
--
作者：
D. Pak;D. Lea;J. Kennett
通讯作者：
J. Kennett
影响因子：
64.8
作者：
Andersen, KK;Azuma, N;White, JWC
通讯作者：
White, JWC