Influences of high reliefs on isotope hydrology and coupled climate proxies

高地势对同位素水文学和耦合气候代理的影响

• 批准号: 318149778
• 负责人: Privatdozent Dr. Robert van Geldern
• 金额: --
• 依托单位: Lehrstuhl für Angewandte Geologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/318149778?language=en
• 关键词: Influences; reliefs; isotope; hydrology; coupled

Climate proxies such as tree rings rely on stable isotope ratios for the reconstruction of palaeoclimatic conditions. Such information then allow the calibration of models that evaluate and predict ongoing and future effects of global climate change. According to model predictions, the western Mediterranean is a region that will face severe climatic changes. Therefore, the island of Corsica in that region has been the target for palaeoclimate reconstructions by means of dendrochronology and stable isotopes. However, the oxygen stable isotope results from Corsican pines could not yet be interpreted satisfactorily. The oxygen stable isotope values (delta18O) of tree rings mainly depend on the oxygen isotope ratio of local precipitation and soil water. The precipitation delta18O values vary according to temperature, altitude and the moisture source area. Such parameters are determined nowadays rather precise but need to be assumed for the past. An important isotope effect is the so-called altitude effect that describes the relation of the delta18O value of precipitation and altitude. The large global network of isotopes in precipitation (GNIP) database of the International Atomic Energy Agency (IAEA) allows for a good regional estimate of isotope effects. However, things become more difficult in regions with high and steep mountain reliefs. Some latest publications suggest that the altitude gradient is absent in such regions during specific seasons. The reason for that observation could be seasonal height variations of the atmospheric planetary boundary layer (PBL). This isotope hydrology proposal is part of the project package CorsicArchive that also consists of interlinking proposals for climate, dendroisotopes and dendroecology. It is planned to install and regularly sample nine isotope precipitation samplers along an east-west altitudinal transect. This proposal will specifically explore the dynamics of the PBL and the isotope altitude effect. Additional questions relate to moisture source of air masses and the local moisture recycling within the islands hydrologic cycle. Furthermore, soil water and surface water analyses are planned to trace and quantify changes of the delta18O values along the pathway of water to the tree rings. The approach of this proposal aims to fill the gaps in the current knowledge of isotope hydrology of high reliefs and will finally lead to a more robust interpretation of related climate proxies in a climate change sensitive region. With respect to the current climate change, it is essential to understand climatic variations and its triggers in the past to better predict future changes.

树木年轮等气候指标依赖稳定的同位素比率来重建古气候条件。然后，这些信息可以对评估和预测全球气候变化持续和未来影响的模型进行校准。根据模型预测，西地中海是一个将面临严重气候变化的地区。因此，该地区的科西嘉岛一直是利用年代学和稳定同位素方法重建古气候的目标。然而，科西嘉松的氧稳定同位素结果尚不能令人满意地解释。树木年轮的氧稳定同位素值(Delta18O)主要取决于当地降水和土壤水的氧同位素比值。降水Delta18O值随温度、海拔高度和水汽源区的不同而不同。这样的参数现在被确定得相当精确，但需要为过去假设。一个重要的同位素效应是所谓的海拔效应，它描述了降水的delta18O值与海拔的关系。国际原子能机构(原子能机构)的大型全球降水中的同位素网络(GNIP)数据库使区域能够很好地估计同位素的影响。然而，在山势高而陡峭的地区，情况变得更加困难。一些最新的出版物表明，在特定的季节，这些地区没有海拔梯度。这种观测的原因可能是大气行星边界层(PBL)的季节高度变化。这项同位素水文学提案是CORSICCARIVE一揽子项目的一部分，该项目还包括气候、树状同位素和树状生态方面的相关建议。计划沿东西垂直断面安装并定期采样9个同位素降水采样器。这项提议将具体探讨PBL的动力学和同位素高度效应。其他问题涉及气团的水分来源和岛屿水文循环内的当地水分循环。此外，计划进行土壤水和地表水分析，以跟踪和量化沿着水到树轮的路径的delta18O值的变化。这一建议的做法旨在填补目前对高浮雕的同位素水文学知识的空白，并最终将导致对气候变化敏感地区的相关气候指标作出更有力的解释。关于目前的气候变化，了解过去的气候变化及其触发因素对于更好地预测未来的变化是至关重要的。

项目成果

Riverine carbon dioxide evasion along a high-relief watercourse derived from seasonal dynamics of the water-atmosphere gas exchange.

• DOI: 10.1016/j.scitotenv.2018.12.158
• 发表时间: 2019-03
• 期刊: The Science of the total environment
• 作者: T. Juhlke;R. van Geldern;F. Huneau;É. Garel;S. Santoni;H. Hemmerle;J. Barth

Altitude isotope effects in Mediterranean high-relief terrains: a correction method to utilize stream water data

• DOI: 10.1080/02626667.2021.1928672
• 发表时间: 2021-05
• 期刊: Hydrological Sciences Journal
• 影响因子: 3.5
• 作者: H. Hemmerle;R. van Geldern;T. Juhlke;F. Huneau;É. Garel;S. Santoni;J. Barth

Assessing moisture sources of precipitation in the Western Pamir Mountains (Tajikistan, Central Asia) using deuterium excess

• DOI: 10.1080/16000889.2019.1601987
• 发表时间: 2019-01
• 期刊: Tellus B: Chemical and Physical Meteorology
• 作者: T. Juhlke;C. Meier;R. van Geldern;K. Vanselow;Jakob Wernicke;J. Baidulloeva;J. Barth;S. Weise