Reconstructing Changes in Regional Hydrology during the Holocene employing Novel Stable Isotope and Molecular Proxies

利用新型稳定同位素和分子代理重建全新世区域水文学的变化

• 批准号: 104302536
• 负责人: Dr. Dirk Sachse
• 金额: --
• 依托单位: Sektion 4.6: Geomorphologie
• 依托单位国家: 德国
• 项目类别: Independent Junior Research Groups
• 财政年份: 2009
• 资助国家: 德国
• 起止时间: 2008-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/104302536?language=en
• 关键词: Reconstructing; Changes; Regional; Hydrology; during

The timing and magnitude of the response of the continental hydrological cycle to global climate changes is still not well understood. Especially abrupt climatic change during the Holocene is often most severely expressed through changes in hydrology on the continents. Knowledge of these processes and it’s causes however, is essential, when trying to predict the consequences of anthropogenic climate change on hydrological processes. Differences in regional responses of the terrestrial hydrological system are largely unknown due to a lack of direct hydrological proxies and paleoclimate records. A promising new paleohydrological proxy, the hydrogen isotopic composition of individual lipid biomarkers, has been emerging in the last years, which is capable of enhancing our knowledge about changes in hydrology over the continents. Therefore, I propose to establish an Emmy Noether Research Group with the following aims: (1) Advance and refine the use of lipid biomarker hydrogen isotope measurement as a paleohydrological proxy for terrestrial ecosystems through comprehensive calibration studies. Through studies on plants under controlled greenhouse conditions as well as of plants and soils along steep (natural) hydrological gradients, we will be able to understand the factors influencing the hydrogen isotopic composition of terrestrial plant derived lipids – apart from the source water isotopic composition. This work will fully establish the use of lipid biomarker hydrogen isotopes as a viable paleohydrological proxy for terrestrial ecosystems. (2) Obtain high-resolution records of changes in precipitation, plant evapotranspiration and atmospheric circulation throughout the Holocene from temperate, arid and highly seasonal climatic regimes. By applying compound-specific isotope analysis to excellent continental climate archives, maar lakes, throughout the Holocene we will be able to determine the timing and magnitude of regional hydrological changes. We will compare the response of this new proxy to changes in hydrology for different climate mean states (temperate, arid and monsoonal climate regimes). Special emphasis will be placed on the nature and timing of precipitation and evapotranspiration changes during abrupt climate transitions, such as the Younger Dryas in Central Europe. Our work will also provide better constraints on variations in precipitation as a consequence of changing monsoonal patterns in the Tropics, a region which will most harshly effected by changing hydrology through anthropogenic climate change. The outcome of the work proposed here will significantly enhance our knowledge about changes in continental paleohydrology throughout the Holocene as well as establish the use of a new paleohydrological proxy within the paleoclimate community.

大陆水文循环对全球气候变化响应的时间和幅度仍然没有很好的了解。特别是全新世气候的突然变化，往往最严重地表现为大陆水文的变化。然而，当试图预测人为气候变化对水文过程的影响时，了解这些过程及其原因是必不可少的。由于缺乏直接的水文代用指标和古气候记录，陆地水文系统的区域响应差异在很大程度上是未知的。近年来，一种新的有前途的古水文代用指标--单个脂质生物标志物的氢同位素组成逐渐出现，它能够增强我们对各大陆水文变化的认识。因此，我建议建立一个埃米诺特研究小组，其目标如下：（1）通过全面的校准研究，推进和完善使用脂质生物标志物氢同位素测量作为陆地生态系统的古水文代用品。通过对受控温室条件下的植物以及沿着陡峭（自然）水文梯度的植物和土壤的研究，我们将能够了解影响陆生植物衍生脂质的氢同位素组成的因素-除了源水同位素组成。这项工作将充分建立使用脂质生物标志物氢同位素作为一个可行的古水文陆地生态系统的代理。(2)从温带、干旱和季节性气候状况中获取整个全新世降水、植物蒸散和大气环流变化的高分辨率记录。通过将特定化合物的同位素分析应用于整个全新世的优秀大陆气候档案，玛珥湖，我们将能够确定区域水文变化的时间和幅度。我们将比较不同的气候平均状态（温带，干旱和季风气候制度）的水文变化，这个新的代理的响应。将特别强调在气候突变期间，如中欧的新仙女木期，降水和蒸散量变化的性质和时间。我们的工作还将提供更好的约束降水变化的结果，在热带，这将是最严重的影响，通过人为气候变化而改变水文的季风模式。这里提出的工作成果将显着提高我们的知识，在整个全新世大陆古水文的变化，以及建立一个新的古水文代理内的古气候社区。