Do paleoclimate proxies agree? A test comparing 19 late Holocene climate and sea‐ice reconstructions from Icelandic marine and lake sediments |
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Authors: | Yarrow Axford Camilla S Andresen John T Andrews Simon T Belt Áslaug Geirsdóttir Guillaume Massé Gifford H Miller Sædís Ólafsdóttir Lindsay L Vare |
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Institution: | 1. Department of Earth and Planetary Sciences, Northwestern University, Evanston, IL 60208 USA;2. Department of Marine Geology and Glaciology, Geological Survey of Denmark and Greenland, Copenhagen, Denmark;3. Institute of Arctic and Alpine Research, University of Colorado, Boulder, Colorado, USA;4. Department of Geological Sciences, University of Colorado, Boulder, Colorado, USA;5. Petroleum and Environmental Geochemistry Group, Biogeochemistry Research Centre, University of Plymouth, Plymouth, UK;6. Institute of Earth Sciences and Department of Earth Sciences, University of Iceland, Reykjavík, Iceland;7. LOCEAN, UMR7159 CNRS/UPMC/IRD/MNHN, Paris, France |
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Abstract: | Geochemical, mineralogical and biological indicators preserved in sediments are widely used to reconstruct past climate change, but proxies differ in the degree to which their utility as climate indicators has been validated via laboratory experiments, modern spatial calibrations, or down‐core comparisons with instrumental climate data. Multi‐proxy studies provide another means of evaluating interpretations of proxies. This paper presents a multi‐proxy assessment comparing 19 sub‐centennially resolved late Holocene proxy records, covering the period 300–1900 AD, from seven Icelandic marine and lacustrine core sites. We employ simple statistical comparisons between proxy reconstructions to evaluate their correlations over time and, ultimately, their utility as proxies for regional climate. Proxies examined include oxygen isotopic composition of benthic and planktonic foraminifera, abundance of the sea‐ice biomarker IP25, allochthonous quartz in marine sediments (a proxy for drift ice around Iceland), marine carbonate abundance, total organic carbon concentration, chironomid assemblages, lacustrine biogenic silica and carbon/nitrogen ratios in lake sediments. Most of the examined proxy records, including temperature and sea‐ice proxies, correlate strongly with each other over multi‐centennial timescales, and thus do appear to record changes in regional climate. Copyright © 2011 John Wiley & Sons, Ltd. |
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Keywords: | IP25 North Atlantic paleoceanography paleolimnology principal components analysis |
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