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.

我们建议揭示过去千年和未来全球变暖下北海南部区域海平面和暴风雨的信号，以检验现有的基于代理的海平面重建包含迄今为止被低估的气候成分。为了解决这一假设，我们将来自活动盐沼和化石圩田沉积物的高分辨率代理数据与区域模型实验的结果结合起来，这有助于理解风暴洪水变化背后的相关机制，并使我们能够估计暴雨洪水变化的演变。气候变化。具体来说我们希望实现以下目标：1）生成过去千年的相对海平面和风暴强度数据系列，2）评估当地风暴气候变化对基于代理的海平面重建的影响，3）验证基于代理的风暴数据系列，4) 德国湾极端风暴洪水变化的量化及其相关强迫机制的调查，5) 未来全球变暖下极端风暴洪水变化的估计，以及 6) 响应调查现代盐沼环境对区域海平面和气候变化的影响。代理方法和模型方法将共同重点了解上个世纪的风暴洪水变化和相关驱动因素，这些沉积物将以中世纪化石盐沼沉积物为核心。对早期现代圩田的详细沉积学和地球化学数据将有助于重建沉积环境，并识别风暴潮层，应用有孔虫传递函数将提供有关相对高度的信息。相对于潮汐框架的淹没变化将由区域地球系统模型实验来补充，这些实验将调查过去千年选定时间间隔内北海的气候变化和风暴频率。德国湾极端海平面变化的年代际变化与相关的大规模气候变化之间的关系在上个千年的模拟中发现的巨大极值变化表明，估计未来海平面极值的标准方法并没有考虑到它们。满的变异性频谱和典型的集合大小不足以将信号与噪声分开，因此我们将采用大型集合方法来估计极端海平面统计数据的未来变化，从而检测潜在的气候变化信号。首次尝试通过直接结合沉积物档案和气候模拟信息的代理数据来重建北海南部海平面变化和风暴的强迫机制和沿海影响。