SGER: North Atlantic Climate Variability from a Nonlinear Perspective

Project: Research project

Project Details


This award, under the auspices of the Small Grants for Exploratory Research (SGER) program, will help support the development of a novel set of nonlinear tools and their application to the analysis of a well-known climatic event, the North Atlantic Oscillation (NAO). Success of this project could demonstrate the value of nonlinear techniques in paleoclimate studies, reveal strengths and weaknesses of linear versus nonlinear techniques, and contribute to better understanding of variability in climate at time scales of societal interest.

The crux of the reason for pursuing this exploratory project is that much paleoclimatic research relies on a strong form of the uniformitarian hypothesis: a short term correlation between a particular sedimentary characteristic and a climatic variable is applied to a longer sedimentary record to reconstruct the climatic variable. The danger in such an approach became apparent the wider science community, when three independent, less-uniformitarian paleothermometers showed that a short-term calibration between mean-annual temperature and stable-isotopic ratios of water in ice underestimated past temperature changes in Greenland by threefold.

The researcher and his colleagues suggest that one way to improve confidence in such analyses is to follow a completely independent uniformitarian analysis pathway and compare results. The statistical tools used commonly in uniformitarian paleoclimatic analyses are linear. Robust nonlinear 'neural network' techniques have been developed in diverse fields, and the researcher has assembled appropriate nonlinear tools and applied them to reconstruction of paleoclimatic conditions in West Antarctica.

The strategy is to apply these tools to one of the classic paleoclimatic problems: reconstruction of the history of the North Atlantic Oscillation (NAO). He will assess whether the nonlinear techniques do a better job in reconstructing this important climatic feature in validation intervals, and whether new insights are provided. If, as he and his colleagues suspect, the new techniques are better in the validation interval, then the longer NAO history they produce will be of use in broader studies, and differences between it and previous reconstructions will provide one estimate of the uncertainty in paleoclimatic research.

The broader importance of the proposed research is far reaching because if the researchers are successful, they will provide a new tool for improving the confidence of paleoclimatic reconstructions.

Effective start/end date7/1/046/30/05


  • National Science Foundation: $90,301.00


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