Unraveling the signals of sea level and storminess of the past millennium (southern North Sea; SEASTORM)

揭开过去千年海平面和暴风雨的信号（北海南部；SEASTORM）

• 批准号: 313854035
• 负责人: Professor Dr. Christian Betzler
• 金额: --
• 依托单位: Max-Planck-Institut für Meteorologie (MPI-M)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/313854035?language=en
• 关键词: Unraveling; signals; sea; level; storminess

We propose to unravel the signals of regional sea level and storminess of the southern North Sea during the past millennium and under future global warming. The hypothesis to test is that existing proxy-based sea-level reconstructions bear a so far underestimated climate component. In order to address this hypothesis we combine high-resolution proxy data from active salt marshes and fossil polder deposits with results from regional model experiments, which help to understand the relevant mechanisms behind storm flood variability and allow us to estimate the evolution of storm flood variability under climate change. Specifically we want to address the following objectives: 1) Generation of data series of relative sea level and storminess of the past millennium, 2) Evaluation of the impacts of shifts in local storm climate on proxy-based sea-level reconstructions, 3) Validation of the proxy-based data series of storminess, 4) Quantification of extreme storm flood variability in the German Bight and investigation of their associated forcing mechanisms, 5) Estimation of extreme storm flood variability under future global warming, and 6) Investigation of the response of modern salt marsh environments to regional sea-level and climate change.
Both proxy and model approaches will jointly focus on understanding storm flood variability and associated drivers. Sediments of the past century will be cored in naturally grown salt marshes. Fossil marsh sediments from medieval to early modern polders will be further evaluated. Detailed sedimentological and geochemical data will allow for reconstruction of the depositional environments and for the identification of storm-surge layers. Application of a foraminiferal transfer function will deliver information on relative elevation and submergence changes with respect to the tidal frame. The proxy studies will be complemented by regional Earth System Model experiments investigating the climate variability and storm frequency of the North Sea for selected time intervals of the past millennium. These data will be used to study the relationships between decadal variations of extreme sea-level variability in the German Bight and associated large-scale climate variations. The large extreme value variations found in the last millennium simulations have shown that the standard approach to estimate future sea-level extremes does not account for their full variability spectrum and the typical ensemble size is not sufficient to separate signal from noise. We will therefore employ a large ensemble approach to estimate future changes in extreme sea-level statistics, allowing the detection of a potential climate change signal. 
Our project will provide the first attempt to reconstruct the forcing mechanisms and coastal impacts of sea-level variability and storminess of the southern North Sea by directly combining proxy data from sediment archives and climate modeling information.

我们建议在过去的千年以及未来的全球变暖下揭示北海地区海平面和北海风暴的信号。测试的假设是，现有的基于代理的海平面重建迄今为止低估了气候成分。为了解决这一假设，我们结合了来自活性盐沼和化石岩石沉积物的高分辨率替代数据与区域模型实验的结果，这有助于理解暴风雨洪水变异性背后的相关机制，并使我们能够估计气候变化下风暴洪水变化的演变。具体而言，我们要解决以下对象：1）在过去千年的相对海平面和暴风雨中生成数据系列的生成，2）评估当地风暴中转变对基于代理的海平面重建的影响的影响，3）验证基于代理的数据系列的代理数据系列的验证；变暖，以及6）对现代盐沼环境对区域海平面和气候变化的反应进行调查。代理和模型方法将共同关注理解雨水洪水的可变性和相关驱动因素。上个世纪的驱动因素将在自然种植的盐沼泽中加油。将进一步评估从中世纪到早期现代polder的化石沼泽沉积物。详细的沉积学和地球化学数据将允许重建沉积环境以及识别暴风雨层层。有孔虫传递功能的应用将提供有关潮汐框架相对高程和浸没变化的信息。代理研究将通过区域地球系统模型实验完成，该实验研究了过去千年的选定时间间隔的北海气候变异性和风暴频率。这些数据将用于研究德国距离中极端海平面变异性的十年变化与相关的大规模气候变化之间的关系。在上一个千年模拟中发现的大型极值变化表明，估计未来海平面极端的标准方法不能解释其完整的可变性谱，而典型的整体大小不足以将信号与噪声分开。因此，我们将采用大型合奏方法来估计极端海平面统计的未来变化，从而允许检测潜在的气候变化信号。我们的项目将提供首次尝试，以通过直接结合沉积物档案中的代理数据和气候建模信息来重建海平面变异性和沿海风险的强迫机制和沿海影响。