Droughts, flooding events, and shifts in water sources and seasonality characterize last interglacial Levant climate
Droughts, flooding events, and shifts in water sources and seasonality characterize last interglacial Levant climate
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干旱、洪水事件以及水源和季节性的变化是末次间冰期黎凡特气候的特征
DOI：
10.1016/j.quascirev.2020.106546
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发表时间：
2020
影响因子：
4
通讯作者：
Stein, Mordechai
中科院分区：
文献类型：
--
作者：
Kiro, Yael;Goldstein, Steven L.;Kushnir, Yochanan;Olson, Jennifer M.;Bolge, Louise;Lazar, Boaz;Stein, Mordechai
现代观测记录表明，由于气候变暖，世界半干旱和干旱地区干旱频率增加，降水和洪水更加密集。气候模型预测，这种情况将在未来加剧，影响数百万人。古气候研究可以通过记录过去的气候变化来补充短期的现代观测记录和模型预测。在这里，我们报告了在异常温暖的末次间冰期海洋同位素阶段（MIS）5e期间东地中海降水的地理来源，强度和季节性的重大变化，反映了雨带和沙漠带的全球变化，基于死海矿物沉淀物中的234 U/238 U比率，结合气候模型模拟的证据。在死海集水区，234 U/238 U比率是水源的指标，约旦河（来自北部）和西部集水区显示出高的活动比，在1.5-1.7之间，东部和南部集水区和山洪（西南部、南部和东部）的比率较低，为1.0-1.2。在死海水和沉淀矿物中，234 U/238 U在冰期和间冰期几乎总是在1.45-1.55之间。然而，在末次间冰期MIS 5e日射峰值期间（127-122 ka），其值下降到1.2-1.3，然后在其末期（122-116 ka）下降到1.0。在日照高峰期，铀同位素数据，结合气候模式运行强迫与周期轨道和温室气体浓度，表明与非洲夏季风在死海流域的降雨量占年降雨量的50%左右，形成鲜明对比，今天干燥的夏天。地球化学证据表明，在日照高峰之后，该地区经历了一个极端干燥的时期（尽管不时有潮湿的间隔），这意味着沙漠带的扩张，类似于人为变暖的预测影响。这种干燥部分地得到了气候模式运行的支持，这些模式运行是在轨道参数发生适当变化的情况下被迫进行的。极端干燥在MIS 5 e晚期之间的122-116 ka反映了地中海风暴系统的主要减弱，导致约旦河流量的大幅下降（由死海的低234 U/238 U比值表示）和与非洲季风相关的降水相对增加，转向秋季。约旦河的流量估计是现在的10%（1964年以前，在约旦河及其源头被大规模改道供人类使用之前）。这种变化如果在未来发生，将对政治敏感的中东地区未来的水资源供应产生严重影响。
Modern observations document increased drought frequency together with more intense precipitation and flooding in the world’s semi-arid and arid regions as a consequence of the warming climate. Climate models predict that such conditions will intensify in the future, impacting millions of people. Paleoclimate studies can complement the short modern observational record and model projections by documenting climate changes in the past. Here we report major shifts in the geographic sources, intensity, and seasonality of Eastern Mediterranean precipitation during the unusually warm last interglacial period Marine Isotope Stage (MIS) 5e, reflecting global shifts in the rain and desert belts, based on234U/238U-ratios in mineral precipitates in the Dead Sea, combined with evidence from climate model simulations.In the Dead Sea catchment234U/238U ratios are indicators of water sources, where the Jordan River (flowing from the north) and the western catchments show high activity ratios between ∼1.5–1.7, and the eastern and southern catchments and flash floods (in the south-west, south and east) show lower ratios of 1.0–1.2. In Dead Sea water and precipitated minerals,234U/238U is nearly always ∼1.45–1.55 during both glacials and interglacials. However, during the last interglacial MIS 5e insolation peak (∼127–122 ka) its value decreased to 1.2–1.3, and then to ∼1.0 towards its end (∼122–116 ka). During the insolation peak, the U-isotope data, combined with climate model runs forced with period orbital and greenhouse gas concentrations, indicate that rainfall associated with the African Summer Monsoon in the Dead Sea catchment accounted for ∼50% of the total annual rainfall, in stark contrast to present-day dry summers. The geochemical evidence indicates that following the insolation peak the region experienced an extremely dry period (although punctuated with wetter intervals), signifying expansion of the desert belt, similar to predicted effects of anthropogenic warming. This drying is partly supported by climate model runs forced with the appropriate changes in orbital parameters. The extreme drying during late MIS 5e between ∼122–116 ka reflected a major weakening of Mediterranean storm systems, resulting in a major decline of the Jordan River flow (indicated by the low234U/238U ratios in the Dead Sea) and a relative increase in precipitation associated with the African Monsoon, shifting towards autumn. The Jordan River flow is estimated to be ∼10% of the present-day (pre-1964, prior to major diversion of the Jordan River and its sources for human use). Such changes, if they occur in the future, have serious implications for future water availability in the politically sensitive Middle East.
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DOI：
--
发表时间：
2014
期刊：
影响因子：
--
作者：
M. Bar
通讯作者：
M. Bar
死海盆地最后一个间冰期萨姆拉湖的地层学、沉积环境和水平重建
影响因子：
2.3
作者：
N. Waldmann;M. Stein;D. Arizteguí;A. Starinsky
通讯作者：
A. Starinsky
约旦南部（北纬 29°）的广阔埃米亚古湖
影响因子：
3.9
作者：
N. Petit;P. Carbonel;J. Reyss;P. Sanlaville;A. Abed;R. Bourrouilh;M. Fontugne;Suha Yasin
通讯作者：
Suha Yasin
影响因子：
64.8
作者：
Luethi, Dieter;Le Floch, Martine;Stocker, Thomas F.
通讯作者：
Stocker, Thomas F.
以色列内盖夫沙漠重大洪水的天气气候学
DOI：
--
发表时间：
2002
期刊：
影响因子：
--
作者：
R. Kahana;B. Ziv;Y. Enzel;U. Dayan
通讯作者：
U. Dayan