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.
