P2C2: Testing for the Physical Origin of Tree-Ring Divergence

来自树木年轮的记录对地表温度的重建做出了独特的贡献，因为它们在陆地上分布均匀，具有年度分辨率，可以追溯到几个世纪甚至数千年前。基于年轮生长的重建的解释是复杂的，因为当原始年轮观测被合并到年表中时，可能会损失信息，并且气候对年轮生长的各种影响。这项研究使用档案数据和新开发的高纬度年表来测试去趋势方法和多变量气候控制对整个北极树木年轮记录的影响。将模拟导致基于树轮的气候重建的过程，从气候对树木生长的影响开始，通过采样和年表构建来进行。然后，这一框架将被用来检验关于气候过程和方法方法对由此产生的年表的影响的假设，特别注意去趋势和光照可用性对气候重建的影响。还将从高纬度地区收集新的树轮核心，以测试光环境中的小尺度变化对树轮生长的影响。该项目及其相关的方法学进展将提高对基于树轮的气候指标的理解，并导致改进气候重建。项目过程中产生的代码和数据将公之于众。资金还将支持旧金山州立大学研究生和本科生的研究、教育和指导。

Records derived from tree rings make a unique contribution to reconstructions of surface temperature because they are well-distributed on land, have annual resolution, and extend back centuries or even millennia. Interpretation of reconstructions based on tree-ring growth is complicated by the potential loss of information when raw tree-ring observations are combined into chronologies, and by the variety of climate influences on tree-ring growth. This research tests for the influence of detrending methodology and multivariate climate control on tree-ring records across the Arctic using both archival data and newly developed high-latitude chronologies. The process leading to tree-ring based climate reconstructions will be modeled, starting with climate influences on tree growth and progressing through sampling and chronology construction. This framework will then be used to test hypotheses about the influence of climate processes and methodological approaches on the resulting chronologies, placing particular attention to the effects of detrending and light availability on climate reconstructions. New tree-ring cores from high-latitude sites will also be collected in order to test for an influence of small-scale variability in the light environment on tree-ring growth. This project and its associated methodological advances will improve understanding of tree-ring based climate proxies and lead to improved climate reconstructions. Codes and data generated in the course of the project will be made publically available. Funding will also support the research, education, and mentoring of graduate and undergraduate students at San Francisco State University.