Reconstruction of decadal to centennial Holocene variability of the North Atlantic Oscillation using speleothems from Morocco

使用来自摩洛哥的洞穴重建北大西洋涛动的十年至百年全新世变化

• 批准号: 253508294
• 负责人: Dr. Jasper Wassenburg
• 金额: --
• 依托单位: Arbeitsgruppe Speläothemforschung
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/253508294?language=en
• 关键词: Reconstruction; decadal; centennial; Holocene; variability

The North Atlantic Oscillation (NAO; the dominating atmospheric pressure mode in the North Atlantic region) has large ecological and socio-economical impact by affecting both marine and continental winter climate in the Northern Hemisphere. Understanding the mechanisms influencing the NAO as well as its relationship to other climate parameters is, thus, of great importance. Links between the NAO, solar activity and the ocean-atmosphere-sea ice system have been proposed. Since instrumental climate datasets do not extend back beyond the Anthropocene, the natural variability of the NAO can only be assessed by paleoclimate reconstructions. However, only a few continental NAO reconstructions extending beyond the instrumental data period are currently available. The Holocene evolution and forcing factors of the NAO are, thus, a matter of debate in the scientific community. In the framework of the proponents PhD thesis, stalagmites from caves in the Middle Atlas, NW Morocco, were used to reconstruct rainfall variability during the Holocene. NW Morocco is very sensitive to changes in the state of the NAO, and the speleothem data indicated significant past variability of the NAO on multi-centennial timescales. However, information on decadal to centennial timescales requires (near-) annual resolution climate reconstructions. At present these are not available. The proposed project focuses on stalagmites from two caves in Morocco, which have provided climate records with a relationship to the NAO. The aims are (i) to construct one master record based on the common rainfall signals of different stalagmite records from the same cave, and (ii) to provide a Holocene reconstruction of effective rainfall with annual resolution. Frequency analysis is employed to detect significant periodic components. Time intervals dominated by specific decadal to centennial frequencies or a persistent positive/negative state of the NAO will be compared with potential NAO forcing factors (i.e. solar activity, oceanic parameters, sea ice extension).

北大西洋涛动（NAO;北大西洋区域的主导大气压力模式）通过影响北方半球的海洋和大陆冬季气候而具有巨大的生态和社会经济影响。因此，了解影响NAO的机制及其与其他气候参数的关系非常重要。有人提出NAO、太阳活动和海洋-大气-海冰系统之间的联系。由于仪器气候数据集不延伸到人类世之外，NAO的自然变率只能通过古气候重建来评估。然而，目前只有少数几个大陆NAO重建延伸到仪器数据期之外。因此，NAO的全新世演变和强迫因素是科学界争论的问题。在支持者的博士论文的框架，石笋中阿特拉斯，西北摩洛哥，洞穴被用来重建降雨量的变化在全新世。西北摩洛哥是非常敏感的NAO的状态的变化，洞穴沉积物数据表明显着的过去的变化NAO的多百年的时间尺度。然而，十年到百年时间尺度的信息需要（近）年度分辨率的气候重建。目前，这些资料并不齐备。拟议的项目侧重于来自摩洛哥两个洞穴的石笋，这两个洞穴提供了与NAO有关的气候记录。其目的是（i）构建一个主记录的基础上，共同的降雨信号的不同石笋记录从同一个洞穴，（ii）提供一个全新世重建的有效降雨量与年分辨率。频率分析用于检测显著的周期性分量。由特定的十年到百年频率或NAO的持续正/负状态主导的时间间隔将与潜在的NAO强迫因子（即太阳活动，海洋参数，海冰扩展）进行比较。

项目成果

Intra- and inter-annual uranium concentration variability in a Belizean stalagmite controlled by prior aragonite precipitation : a new tool for reconstructing hydro-climate using aragonitic speleothems.

• DOI: 10.1016/j.gca.2016.06.037
• 发表时间: 2016-10
• 期刊: Geochimica et Cosmochimica Acta
• 影响因子: 5
• 作者: R. A. Jamieson;J. Baldini;M. Brett;J. Taylor;Harriet E. Ridley;C. Ottley;Keith M. Prufer;J. Wassenburg;D. Scholz;S. Breitenbach

Sr-isotope analysis of speleothems by LA-MC-ICP-MS: High temporal resolution and fast data acquisition

通过 LA-MC-ICP-MS 对洞穴沉积物进行 Sr 同位素分析：高时间分辨率和快速数据采集

• DOI: 10.1016/j.chemgeo.2017.08.012
• 发表时间: 2017
• 期刊: Chemical Geology
• 影响因子: 3.9
• 作者: Wassenburg;Jochum;Breitenbach;Scholz
• 通讯作者: Scholz

Determination of aragonite trace element distribution coefficients from speleothem calcite–aragonite transitions

• DOI: 10.1016/j.gca.2016.06.036
• 发表时间: 2016-10
• 期刊: Geochimica et Cosmochimica Acta
• 影响因子: 5
• 作者: J. Wassenburg;D. Scholz;K. Jochum;Hai Cheng;J. Oster;A. Immenhauser;D. Richter;T. Häger;R. A. Jamieson;J. Baldini;D. Hoffmann;S. Breitenbach

Speleothem records decadal to multidecadal hydroclimate variations in southwestern Morocco during the last millennium

• DOI: 10.1016/j.epsl.2017.07.045
• 发表时间: 2017-10-15
• 期刊: EARTH AND PLANETARY SCIENCE LETTERS
• 影响因子: 5.3
• 作者: Ait Brahim, Yassine;Cheng, Hai;Bouchaou, Lhoussaine
• 通讯作者: Bouchaou, Lhoussaine

Reorganization of the North Atlantic Oscillation during early Holocene deglaciation

• DOI: 10.1038/ngeo2767
• 发表时间: 2016-07
• 期刊: Nature Geoscience
• 影响因子: 18.3
• 作者: J. Wassenburg;S. Dietrich;J. Fietzke;J. Fohlmeister;K. Jochum;D. Scholz;D. Richter;A. Sabaoui;C. Spötl;G. Lohmann;M. Andreae;A. Immenhauser