Speleothem records decadal to multidecadal hydroclimate variations in southwestern Morocco during the last millennium
Speleothem records decadal to multidecadal hydroclimate variations in southwestern Morocco during the last millennium
复制标题
DOI：
10.1016/j.epsl.2017.07.045
复制
发表时间：
2017-10-15
影响因子：
5.3
通讯作者：
Bouchaou, Lhoussaine
中科院分区：
文献类型：
--
作者：
Ait Brahim, Yassine;Cheng, Hai;Bouchaou, Lhoussaine
这项研究首次记录了摩洛哥西南部近1000年来的高分辨率稳定同位素(O-18和C-13)和微量元素(镁和锶)。我们的记录揭示了干旱和湿润时期之间相当大的十年到几十年的波动，与区域古记录一致，中世纪气候异常(MCA)期间普遍的干旱条件，小冰期(LIA)第二部分更潮湿的条件，以及当前暖期的干燥条件的趋势。这些连贯的区域气候信号表明了共同的气候控制。统计分析表明，在过去的一千年里，摩洛哥西南部的气候仍然受到北大西洋涛动(NAO)和大西洋年代际涛动(AMO)的共同影响。有趣的是，在较长的年代际时间尺度上，较暖的MCA和较冷的LIA可能通过撒哈拉低压的影响影响了北非的区域气候，撒哈拉低分别削弱和加强了MCA和LIA期间来自大西洋的平均水汽流入。(C)2017爱思唯尔B.V.保留所有权利。
This study presents the first well-dated high resolution stable isotope (delta O-18 and delta C-13) and trace element (Mg and Sr) speleothem records from southwestern Morocco covering the last 1000 yrs. Our records reveal substantial decadal to multidecadal swings between dry and humid periods, consistent with regional paleorecords with prevailing dry conditions during the Medieval Climate Anomaly (MCA), wetter conditions during the second part of the Little Ice Age (LIA), and a trend towards dry conditions during the current warm period. These coherent regional climate signals suggest common climate controls. Statistical analyses indicate that the climate of southwestern Morocco remained under the combined influence of both the North Atlantic Oscillation (NAO) and the Atlantic Multidecadal Oscillation (AMO) over the last millennium. Interestingly, the generally warmer MCA and colder LIA at longer multidecadal timescales probably influenced the regional climate in North Africa through the influence on Sahara Low which weakened and strengthened the mean moisture inflow from the Atlantic Ocean during the MCA and LIA respectively. (C) 2017 Elsevier B.V. All rights reserved.