Holocene humid periods of the Levant – evidence from Dead Sea lake-levels
Holocene humid periods of the Levant – evidence from Dead Sea lake-levels
复制标题
DOI：
10.1016/j.quascirev.2023.108312
复制
发表时间：
2023-10
影响因子：
4
通讯作者：
Y. Goldsmith;Ofer Cohen;M. Stein;A. Torfstein;Y. Kiro;Yochanan Kushnir;Y. Bartov;Liran Ben-Moshe;A. Frumkin;N. Lensky;Jonathan Keinan;Lilach Gonen;Y. Enzel
中科院分区：
文献类型：
--
作者：
Y. Goldsmith;Ofer Cohen;M. Stein;A. Torfstein;Y. Kiro;Yochanan Kushnir;Y. Bartov;Liran Ben-Moshe;A. Frumkin;N. Lensky;Jonathan Keinan;Lilach Gonen;Y. Enzel
由于未来几十年全球变暖，预计黎凡特地区的可用水量将下降，预计将对该地区产生重大影响。确定该地区的长期自然降雨变率对于了解区域水文气候对外部气候强迫的响应以及确定未来水文气候变化的背景至关重要。死海（DS）位于黎凡特南部，是一个封闭的盆地湖泊，其大小随可用水量的变化而变化。重建DS湖泊水位随时间的变化提供了自然水文气候变率的定量测量，并可以为局部水文气候对全球气候变化的响应提供信息。本文通过对DS南部盆地新采集的一系列岩心的湖高水位进行研究，对两次主要的全新世高水位暴露进行重新定年，并对所有已发表的DS全新世湖高水位标志物年龄（n = 296个放射性碳年龄）进行整理，构建了全新世DS湖高水位历史。结果表明：东秦纪早期（10 ~ 6.1 kyr cal BP）和晚期（3.6 ~ 0 kyr cal BP）以湿润为主，间或有干期，而中全新世（6.1 ~ 3.6 kyr cal BP）则以相对干期为主。这两个全新世湿润间隔的模式在黎凡特洞穴的蒸馏记录中也很明显（它代表了从蒸汽源到洞穴的降雨总量），表明降雨强度和总水量在整个全新世都是相关的。这两个湿润间隔发生在夏季高日照和低日照条件下，表明它们受到不同气候机制的调节。预测未来黎凡特地区的干燥程度与自然水文气候变率相似，因此，评估人为干燥与自然气候变率是否一致或不一致至关重要。
Water availability in the Levant is predicted to decline due to global warming in the upcoming decades and is expected to substantially impact the region. Determining the long-term natural rainfall variability in this region is essential for understanding the regional hydroclimatic response to external climate forcings and for contextualizing future hydroclimate changes. The Dead Sea (DS), located in the southern Levant, is a closed-basin lake whose size varies as a function of water availability. Reconstructing DS lake-level variations through time provides a quantitative measure of the natural hydroclimate variability and can inform on the local hydroclimate response to changes in global climate. Here, we constructed an updated lake-level history of the Holocene DS by: 1) studying lake high-stands derived from a series of new cores collected in the DS southern basin, 2) re-dating of the two major Holocene high-stand exposures, and 3) compiling all previously published ages of Holocene DS lake-level markers (n = 296 radiocarbon ages). The results show that the early (10–6.1 kyr cal BP) and late Holocene (3.6–0 kyr cal BP) in the DS were predominantly wet albeit punctuated by dry intervals, whereas the middle Holocene (6.1–3.6 kyr cal BP) was most likely relatively dry. This pattern of two Holocene humid intervals is also evident in distillation records derived from Levant speleothem caves (which represent the integrated magnitude of rainout from the vapor source to the caves), indicating that rainfall intensity and total water availability were correlated throughout the Holocene. These two humid intervals occurred during high and low summer insolation conditions, suggesting that they were modulated by different climatic mechanisms. The predicted future drying in the Levant is of similar magnitude to the natural hydroclimate variability and thus, it is crucial to assess whether the anthropogenic drying is in- or out-of phase with the natural climate variability.