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.

该合作项目的总体目标是对树木年轮代理和气候模拟进行数据模型综合，以确定十年至百年气候变化的强度和起源。该研究的科学目标是预测持续一个或多个干旱的风险几十年。 因此，研究小组认为，有必要了解十年至百年（dec-cen）时间尺度的气候变化的起源、模式和幅度。如果十月至十月的变化很弱，研究小组假设气候变化对区域水文气候的影响可能会由于辐射强迫的缓慢变化而显现出来。然而，如果12-12年的变化很大，那么研究小组认为，在任何对气候的理解中，都应该共同考虑大气变暖和自然变率对长时间尺度的综合影响。研究小组特别寻求量化低频的振幅模型、代理和观测中的水文气候变化，同时利用国家大气研究中心制作的一套新的上千年数值气候模型。他们将把统计和动态缩小技术应用于这个整体，包括一次超高（时间）分辨率控制模拟运行，并使用这些结果来推动树木年轮生长的模型。此外，研究人员将重新处理国际树木年轮数据库存档的北半球所有树木年轮宽度和密度测量结果，以优化十月至世纪变异的幅度和空间结构。 这两种产品——来自气候模型的高分辨率树木年轮模拟和新的 12-10 世纪优化树木年轮网络——将使用针对 12-12 世纪变异性的幅度和空间结构的稳健零假设进行评估。这些活动反过来将提高对十二月至世纪的全面变化、其空间足迹及其与未来特大干旱风险的相关性的理解。更广泛的影响包括为古气候研究人员和统计学家组织两次研讨会，以探索新的推断方法这个数据集。此外，对北美树木年轮网络的 12-12 月模式的综合分析将直接解决关于树木年轮记录中时间自相关的起源以及生物持久性对据此估计的气候历史的潜在混杂影响的持续争论。代理人。此外，该项目还将支持两名研究生的研究过程。

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