Temperature Covariance in Tree Ring Reconstructions and Model Simulations Over the Past Millennium
Geophysical Research Letters
MetadataShow full item record
Hartl-Meier, C., Buentgen, U., Smerdon, J., Zorita, E., Krusic, P., Ljungqvist, F., Schneider, L., & et al. (2017). Temperature Covariance in Tree Ring Reconstructions and Model Simulations Over the Past Millennium. Geophysical Research Letters, 44 9458-9469. https://doi.org/10.1002/2017GL073239
Spatial covariance in the simulated temperature evolution over the past millennium has been reported to exceed that of multiproxy-based reconstructions. Here we use tree ring-based temperature reconstructions and state-of-the-art climate model simulations to assess temporal changes in Northern Hemisphere intercontinental temperature covariance during the last 1000 years. Tree ring-only approaches reveal stronger agreement with model simulations compared to multiproxy networks. Although simulated temperatures exhibit a substantial spread among individual models, intercontinental temperature coherency is mainly driven by the cooling of large volcanic eruptions in 1257, 1452, 1600, and 1815 Common Era. The coherence of these synchronizing events appears to be elevated in several climate simulations relative to their own unforced covariance baselines and in comparison to the proxy reconstructions. This suggests that some models likely overestimate the amplitude of abrupt summer cooling in response to volcanic eruptions, particularly at larger spatial scales.
paleoclimate, spatial temperature synchrony, millennial scale, radiative forcing, proxy model comparison
Supported by the German Science Foundation, grant 161/9-1 and the U.S. National Science Foundation grant AGS-1602920. U. Büntgen received funding from the Ministry of Education, Youth and Sports of Czech Republic within the National Sustainability Program I (NPU I; GN LO1415).
External DOI: https://doi.org/10.1002/2017GL073239
This record's URL: https://www.repository.cam.ac.uk/handle/1810/274835