Reconstructing Past Climate from Noisy Data
Abstract
Empirical reconstructions of the Northern Hemisphere (NH) temperature in the past millennium based on multiproxy records depict small-amplitude variations followed by a clear warming trend in the past two centuries. We use a coupled atmosphere-ocean model simulation of the past 1000 years as a surrogate climate to test the skill of these methods, particularly at multidecadal and centennial time scales. Idealized proxy records are represented by simulated grid-point temperature, degraded with statistical noise. The centennial variability of the NH temperature is underestimated by the regression-based methods applied here, suggesting that past variations may have been at least a factor of 2 larger than indicated by empirical reconstructions.
- Publication:
-
Science
- Pub Date:
- October 2004
- DOI:
- 10.1126/science.1096109
- Bibcode:
- 2004Sci...306..679V
- Keywords:
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- ATMOS