Western Mediterranean hydro-climatic consequences of Holocene iceberg advances (Bond events)
Western Mediterranean hydro-climatic consequences of Holocene iceberg advances (Bond events)
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DOI：
10.5194/cp-2018-97
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发表时间：
2018-08
期刊：
影响因子：
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通讯作者：
C. Zielhofer;Anne Köhler;Steffen Mischke;A. Benkaddour;Abdeslam Mikdad;William J. Fletcher
中科院分区：
文献类型：
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作者：
C. Zielhofer;Anne Köhler;Steffen Mischke;A. Benkaddour;Abdeslam Mikdad;William J. Fletcher
抽象的。杰拉尔德·C邦德建立了一个全新世系列的北大西洋冰筏碎片事件的基础上，石英和赤铁矿染色颗粒恢复亚极地北大西洋海洋核心。这些所谓的“邦德事件”记录了九个大规模和数百年的北大西洋冷却阶段，这些阶段可能与减少的温盐环流有关。尽管全新世北大西洋冰筏碎片记录的高度突出，但对这项研究的科学评论是：全新世邦德曲线尚未在北大西洋的其他海洋档案中复制，只有很少的古气候研究表明所有单独的邦德事件在自己的记录中。因此，北大西洋副极地和遥远地区之间一致的水文气候遥相关的证据尚不清楚。在这方面，西地中海区域揭示了重建与副极地北大西洋遥相关的关键水文气候地点。特别是，西地中海冬季降水的变化可能是在外热带北大西洋领域的大气-海洋耦合过程的结果。基于西迪阿里湖（中阿特拉斯，摩洛哥）改进的全新世δ 18 O记录，我们将西地中海降水异常与北大西洋邦德事件相关联，以确定西地中海冬季降雨与副极地北大西洋冷却阶段之间可能的遥相关。我们的数据显示，西地中海冬季降雨极小值和债券事件在全新世早期和全新世晚期相反的模式之间存在显着的正相关关系。有证据表明，在整个大西洋大气-海洋系统中存在着持久的水文气候变化，并对中全新世期间的外部强迫作出了反应。关于一个潜在的气候异常约4.2 ka（邦德事件3）在地中海西部，百年尺度的冬季降雨最大值通常是在过去5,000年的交替“湿和凉”和“干和暖”的间隔的整体模式的阶段。
Abstract. Gerald C. Bond established a Holocene series of North Atlantic ice rafted debris events based on quartz and hematite stained grains recovered from subpolar North Atlantic marine cores. These so-called ‘Bond events’ document nine large-scale and multi-centennial North-Atlantic cooling phases that might be linked to a reduced thermohaline circulation. Regardless of the high prominence of the Holocene North Atlantic ice rafted debris record, there are critical scientific comments on the study: the Holocene Bond curve has not yet been replicated in other marine archives of the North Atlantic and there exist only very few palaeo-climatic studies that indicate all individual Bond events in their own record. Therefore, evidence for consistent hydro-climatic teleconnections between the subpolar North Atlantic and distant regions is not clear. In this context, the Western Mediterranean region reveals key hydro-climatic sites for the reconstruction of a teleconnection with the subpolar North Atlantic. In particular, variability of Western Mediterranean winter precipitation might be the result of atmosphere-ocean coupled processes in the outer-tropical North Atlantic realm. Based on an improved Holocene δ18O record from Lake Sidi Ali (Middle Atlas, Morocco) we correlate Western Mediterranean precipitation anomalies with North Atlantic Bond events to identify a probable teleconnection between Western Mediterranean winter rains and subpolar North Atlantic cooling phases. Our data show a noticeable positive correlation between Western Mediterranean winter rain minima and Bond events during the Early Holocene and an opposite pattern during the Late Holocene. There is evidence for an enduring hydro-climatic change in the overall Atlantic atmosphere-ocean system and the response to external forcing during the Mid-Holocene. Regarding a potential climatic anomaly around 4.2 ka (Bond event 3) in the Western Mediterranean, a centennial-scale winter rain maximum is generally in phase with the overall pattern of alternating ‘wet and cool’ and ‘dry and warm’ intervals during the last 5,000 years.