Climate field reconstruction uncertainty arising from multivariate and nonlinear properties of predictors

©2014. American Geophysical Union. All Rights Reserved. Climate field reconstructions (CFRs) of the global annual surface air temperature (SAT) field and associated global area-weighted mean annual temperature (GMAT) are derived in a collection of pseudoproxy experiments for the past millennium. Pse...

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Detalhes bibliográficos
Autores: Evans, M. N., Smerdon, Jason E., Kaplan, A., Tolwinski-Ward, S. E., González-Rouco, J. F.
Formato: artículo
Fecha de publicación:2014
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/111749
Acesso em linha:http://hdl.handle.net/10261/111749
Access Level:acceso abierto
Palavra-chave:Paleoclimate
Pseudoproxy experiment
Climate field reconstruction
Uncertainty
Descrição
Resumo:©2014. American Geophysical Union. All Rights Reserved. Climate field reconstructions (CFRs) of the global annual surface air temperature (SAT) field and associated global area-weighted mean annual temperature (GMAT) are derived in a collection of pseudoproxy experiments for the past millennium. Pseudoproxies are modeled from temperature (T), precipitation (P), T+P, and VS-Lite (VSL), a nonlinear and multivariate proxy system model for tree ring widths. Spatial patterns of reconstruction skill and spectral bias for the T+P and VSL-derived CFRs are similar to those previously shown using temperature-only pseudoproxies but demonstrate overall degraded skill and spectral bias for SAT reconstruction. Analysis of GMAT spectra nevertheless suggests that the true GMAT frequency spectrum is resolved by those pseudoproxies (T, T+P, and VSL) that contain some temperature information. The results suggest that mixed temperature and moisture-responding paleoclimate data may produce actual GMAT reconstructions with skill, error, and spectral characteristics like those expected from univariate and linear temperature responders, but spatially resolved CFR results should be analyzed cautiously. Key Points Uncertainties may be larger than previously estimated from PPEsReconstructed GMAT based on mixed responders is relatively spectrally unbiasedCFRs based on mixed responders should be interpreted with caution