Collaborative Research: P2C2--Quantifying the Risk of Widespread Megadrought in North America

合作研究：P2C2——量化北美大范围特大干旱的风险

• 批准号: 1602564
• 负责人: Toby Ault
• 金额: $ 31.66万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-01 至 2020-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1602564&HistoricalAwards=false
• 关键词: Collaborative; Research; P2C2; Quantifying; Risk

This collaborative project generally aims to undertake a data-model synthesis of tree-ring proxies and climate simulations to identify the strength and origins of decadal-centennial climate variability.The science goal of the research is to anticipate the risk of droughts lasting one or more decades. As such, the research team argues that it is necessary to understand the origins, patterns, and amplitudes of climate variability at decadal to centennial (dec-cen) timescales. If dec-cen variations are weak, the team hypothesizes that climate change impacts on regional hydroclimate will likely unfold as a consequence of slow-varying changes in radiative forcing. If dec-cen variations are strong, however, then the team argues that the combined effects of atmospheric warming and natural variability on long timescales should be considered jointly in any understanding of climate.The research team specifically seeks to quantify the amplitude of low-frequency hydroclimatic variability in models, proxies, and observations, while at the same time utilizing a new suite of last millennium numerical climate models produced by the National Center for Atmospheric Research. They will apply both statistical and dynamical downscaling techniques to this ensemble, including one ultra-high (temporal) resolution control simulation run and use these results to drive forward models of tree-ring growth. Further, the researchers will reprocess all tree-ring width and density measurements from the Northern Hemisphere archived by the International Tree-Ring Databank to optimize the amplitude and spatial structure of dec-cen variability. Both of these products - the high-resolution tree-ring simulations from climate models and the new dec-cen optimized tree-ring network - will be evaluated using a robust null-hypothesis for the amplitude and spatial structure of dec-cen variability. These activities will, in turn, improve the understanding of the full magnitude dec-cen variability, its spatial footprint, and its relevance to future megadrought risk.The Broader Impacts involve organizing two workshops for paleoclimate researchers and statisticians to explore new methods of inference from this dataset. In addition, the comprehensive analysis of dec-cen patterns across the North American tree-ring network will address directly the ongoing debate about the origins of temporal autocorrelation in tree-ring records and the potential confounding effects of biological persistence on climate histories estimated from this proxy. Furthermore, this project will support two graduate students in the course of the research.

该协作项目通常旨在进行树木环代理和气候模拟的数据模型综合，以确定十年中心气候变异性的力量和起源。该研究的科学目标是预测持续数十年的干旱风险。 因此，研究小组认为，有必要了解十年级（DEC-CEN）时标的气候变异性的起源，模式和幅度。如果DEC-CEN的变化较弱，团队假设气候变化对区域氢化气候的影响可能会因辐射强迫速度缓慢变化而展开。但是，如果DEC-CEN的变化很强，那么团队认为，在对气候的任何理解中，应共同考虑大气变暖和自然变异性对长时间尺度的综合影响。专门试图通过模型，PROFIST和NORDEN-MILLENN FILE量使用新的SUITE，同时使用新的SUITE量化了新的SUILE，同时使用新的SUITE量化了新的SUILLEN，同时使用新的SUILLENN cl MILLENN NORNEN，则应专门努力量化低频水文变异性的幅度。大气研究。他们将对此合奏应用统计和动力学缩减技术，包括一个超高（时间）分辨率控制模拟运行，并使用这些结果来推动树环增长的前进模型。此外，研究人员将重新处理来自国际树环数据库存档的北半球的所有树环宽度和密度测量值，以优化DEC-CEN变异性的幅度和空间结构。 这两种产品 - 来自气候模型的高分辨率树环模拟和新的DEC-CEN优化树环网络 - 将使用强大的无效杀伤性来评估DEC-CEN变异性的幅度和空间结构。这些活动反过来将提高对DECEN变异性的全部级别的理解，其空间足迹及其与未来的大型群岛风险的相关性。更广泛的影响涉及为古气候研究人员和统计学家组织两个研讨会，以探索本数据集中的新推理方法。此外，对整个北美树木环网络的DEC-CEN模式的全面分析将直接解决有关树环记录中时间自相关的起源的持续辩论，以及生物持久性对从该代理估计的气候历史的潜在混杂影响。此外，该项目将在研究过程中为两名研究生提供支持。

项目成果

Reconciling disparate views on decadal climate variability from proxies and models

调和代理和模型对十年间气候变化的不同观点

• DOI: 10.22498/pages.25.1.68
• 发表时间: 2017
• 期刊: Past Global Changes Magazine
• 作者: Ault, Toby R