High resolution paleoclimate records and scenarios of climate change and variability

拟议研究的目标是扩大西部内陆地区的湿度敏感树木年轮年表网络，并将这些高分辨率的古气候数据应用于a）创建长期的气候变化数据库。（300-800年）年和季节降水量和径流量的代用记录，B）确定水文气候条件的长期概率（干旱、低流量）低于特定阈值，c）确定水文气候周期的长度、频率和强迫，d）测试和验证全球气候模式（GCM）对降水和干旱的模拟，e）确定生态系统对气候变异的反应，（f）制定未来气候变化及其影响的情景。关于目标c）至f）的研究将涉及与地球、大气、生物和社会科学领域的同事合作。科学方法将包括在干旱地区对树木年轮进行战略性取样，以增加我们重建干旱和径流的长度和密度。研究将针对从湖泊沉积物中获得古生态记录的地点，以及气候影响情景预测流量减少的流域。我们将把我们的草原干旱的树木年轮记录与晚全新世干旱变化、海面温度异常和最近干旱的气候学的仪器和代理记录相关联。我们的树轮记录和GCM控制运行和温室强迫模拟的未来气候之间的水文气候事件的频率分布进行比较。拟议的研究的意义是使用高分辨率的古气候（树木年轮）数据，以获得比仪器记录提供的更长的河流流量和干旱的观点，并将古气候数据应用于生成未来气候情景的过程。新的方面包括将大气环流模型模拟的气候变率与树木年轮捕获的气候信号联系起来，将高分辨率的古气候和古生态记录结合起来，以调查生态系统对气候变率的反应，并向负责规划适应气候变率和变化的决策者提供古气候数据。

The objective of the proposed research is to expand a network of moisture-sensitive tree-ring chronologies in the western interior and apply these high-resolution paleoclimatic data to a) creating long (300-800 years) proxy records of annual and seasonal precipitation and streamflow, b) determining the long-term probability of hydroclimatic conditions (drought, low flows) below specific thresholds, c) identifying the length, frequency and forcing of hydroclimatic cycles, d) testing and verifying global climate model (GCM) simulations of precipitation and drought, e) determining the response of ecosystems to climatic variability, and f) developing scenarios of future climate change and its impacts. Research on objectives c) to f) will involve collaboration with colleagues in the earth, atmospheric, biological and social sciences. The scientific approach will include the strategic sampling of tree rings at dry sites to increase the length and density of our reconstructions of drought and streamflow. Research will be targeted at sites where paleoecological records have been derived from lake sediments, and in watersheds where climate impact scenarios forecast decreasing flow. We will correlate our tree-ring records of prairie drought with instrumental and proxy records of late-Holocene shifts in aridity, sea surface temperatures anomalies, and the climatology of recent droughts. The frequency distributions of hydroclimatic events of specific magnitudes will be compared between our tree-ring records and GCM control runs and greenhouse-forced simulations of future climate. The significance of the proposed research is the use of high-resolution paleoclimatic (tree-ring) data to gain a longer perspective on stream flow and drought than provided by instrumental records, and the application of paleoclimatic data to the process of generating scenarios of future climate. Novel aspects include relating the climate variability simulated by GCMs to the climate signals captured by tree rings, coupling high-resolution paleoclimatic and paleoecological records to investigate the response of ecosystems to climatic variability, and delivering paleoclimatic data to decision makers responsible for the planning of adaptation to climate variability and change.