Erroneous Model Field Representations in Multiple Pseudoproxy Studies: Corrections and Implications

Jason E. Smerdon Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York

Search for other papers by Jason E. Smerdon in
Current site
Google Scholar
PubMed
Close
,
Alexey Kaplan Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York

Search for other papers by Alexey Kaplan in
Current site
Google Scholar
PubMed
Close
, and
Daniel E. Amrhein Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York

Search for other papers by Daniel E. Amrhein in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

Pseudoproxy experiments evaluate statistical methods used to reconstruct climate fields from paleoclimatic proxies during the Common Era. These experiments typically employ output from millennial simulations by general circulation models (GCMs). It is demonstrated that multiple published pseudoproxy studies have used erroneously processed GCM surface temperature fields: the NCAR Community Climate System Model (CCSM), version 1.4, field was incorrectly oriented geographically and the GKSS ECHO-g FOR1 field was corrupted by a hemispheric-scale smoothing in the Western Hemisphere. These problems are not associated with the original model simulations; they instead arose because of incorrect processing of the model data for the pseudoproxy experiments. The consequences of these problems are evaluated for the studies in which the incorrect fields were used. Some quantitative results are invalidated by the findings: these include all experiments that used the corrupted ECHO-g field and those aspects of previous CCSM experiments that focused on Niño-3 reconstructions. Other results derived from the CCSM field can be reinterpreted based on the information provided herein and their qualitative characteristics remain similar.

Corresponding author address: Jason E. Smerdon, Lamont-Doherty Earth Observatory, and Department of Earth and Environmental Sciences, Columbia University, 61 Route 9W, P.O. Box 1000, Palisades, NY 10964. Email: jsmerdon@ldeo.columbia.edu

A comment/reply has been published regarding this article and can be found at http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00065.1 and http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00165.1

Abstract

Pseudoproxy experiments evaluate statistical methods used to reconstruct climate fields from paleoclimatic proxies during the Common Era. These experiments typically employ output from millennial simulations by general circulation models (GCMs). It is demonstrated that multiple published pseudoproxy studies have used erroneously processed GCM surface temperature fields: the NCAR Community Climate System Model (CCSM), version 1.4, field was incorrectly oriented geographically and the GKSS ECHO-g FOR1 field was corrupted by a hemispheric-scale smoothing in the Western Hemisphere. These problems are not associated with the original model simulations; they instead arose because of incorrect processing of the model data for the pseudoproxy experiments. The consequences of these problems are evaluated for the studies in which the incorrect fields were used. Some quantitative results are invalidated by the findings: these include all experiments that used the corrupted ECHO-g field and those aspects of previous CCSM experiments that focused on Niño-3 reconstructions. Other results derived from the CCSM field can be reinterpreted based on the information provided herein and their qualitative characteristics remain similar.

Corresponding author address: Jason E. Smerdon, Lamont-Doherty Earth Observatory, and Department of Earth and Environmental Sciences, Columbia University, 61 Route 9W, P.O. Box 1000, Palisades, NY 10964. Email: jsmerdon@ldeo.columbia.edu

A comment/reply has been published regarding this article and can be found at http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00065.1 and http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00165.1

Save
  • Ammann, C. M., F. Joos, D. S. Schimel, B. L. Otto-Bliesner, and R. A. Tomas, 2007: Solar influence on climate during the past millennium: Results from transient simulations with the NCAR Climate System Model. Proc. Nat. Acad. Sci. USA, 104 , 37133718. doi:10.1073/pnas.0605064103.

    • Search Google Scholar
    • Export Citation
  • Christiansen, B., T. Schmith, and P. Thejll, 2009: A surrogate ensemble study of climate reconstruction methods: Stochasticity and robustness. J. Climate, 22 , 951976.

    • Search Google Scholar
    • Export Citation
  • Collins, W. D., and Coauthors, 2006: The Community Climate System Model version 3 (CCSM3). J. Climate, 19 , 21222143.

  • González-Rouco, F., H. von Storch, and E. Zorita, 2003: Deep soil temperature as proxy for surface air-temperature in a coupled model simulation of the last thousand years. Geophys. Res. Lett., 30 , 2116. doi:10.1029/2003GL018264.

    • Search Google Scholar
    • Export Citation
  • Hegerl, G. C., T. Crowley, M. Allen, W. T. Hyde, H. Pollack, J. Smerdon, and E. Zorita, 2007: Detection of human influence on a new, validated 1500-year climate reconstruction. J. Climate, 20 , 650666.

    • Search Google Scholar
    • Export Citation
  • Jones, P. D., M. New, D. E. Parker, S. Martin, and J. G. Rigor, 1999: Surface air temperature and its changes over the past 150 years. Rev. Geophys., 37 , 173199.

    • Search Google Scholar
    • Export Citation
  • Lee, T. C. K., F. W. Zwiers, and M. Tsao, 2007: Evaluation of proxy-based millennial reconstruction methods. Climate Dyn., 31 , 263281. doi:10.1007/s00382-007-0351-9.

    • Search Google Scholar
    • Export Citation
  • Mann, M. E., and S. Rutherford, 2002: Climate reconstruction using ‘pseudoproxies’. Geophys. Res. Lett., 29 , 1501. doi:10.1029/2001GL014554.

    • Search Google Scholar
    • Export Citation
  • Mann, M. E., R. S. Bradley, and M. K. Hughes, 1998: Global-scale temperature patterns and climate forcing over the past six centuries. Nature, 392 , 779787.

    • Search Google Scholar
    • Export Citation
  • Mann, M. E., S. Rutherford, E. Wahl, and C. Ammann, 2005: Testing the fidelity of methods used in proxy-based reconstructions of past climate. J. Climate, 18 , 40974107.

    • Search Google Scholar
    • Export Citation
  • Mann, M. E., S. Rutherford, E. Wahl, and C. Ammann, 2007a: Robustness of proxy-based climate field reconstruction methods. J. Geophys. Res., 112 , D12109. doi:10.1029/2006JD008272.

    • Search Google Scholar
    • Export Citation
  • Mann, M. E., S. Rutherford, E. Wahl, and C. Ammann, 2007b: Reply. J. Climate, 20 , 56715674.

  • Riedwyl, N., M. Küttel, J. Luterbacher, and H. Wanner, 2009: Comparison of climate field reconstruction techniques: Application to Europe. Climate Dyn., 32 , 381395.

    • Search Google Scholar
    • Export Citation
  • Rutherford, S., M. E. Mann, E. Wahl, and C. Ammann, 2008: Reply to comment by Jason E. Smerdon et al. on “Robustness of proxy-based climate field reconstruction methods”. J. Geophys. Res., 113 , D18107. doi:10.1029/2008JD009964.

    • Search Google Scholar
    • Export Citation
  • Schneider, T., 2001: Analysis of incomplete climate data: Estimation of mean values and covariance matrices and imputation of missing values. J. Climate, 14 , 853871.

    • Search Google Scholar
    • Export Citation
  • Smerdon, J. E., and A. Kaplan, 2007: Comments on “Testing the fidelity of methods used in proxy-based reconstructions of past climate”: The role of the standardization interval. J. Climate, 20 , 56665670.

    • Search Google Scholar
    • Export Citation
  • Smerdon, J. E., A. Kaplan, and D. Chang, 2008a: On the origin of the standardization sensitivity in RegEM climate field reconstructions. J. Climate, 21 , 67106723.

    • Search Google Scholar
    • Export Citation
  • Smerdon, J. E., J. F. González-Rouco, and E. Zorita, 2008b: Comment on “Robustness of proxy-based climate field reconstruction methods” by Michael E. Mann et al. J. Geophys. Res., 113 , D18106. doi:10.1029/2007JD009542.

    • Search Google Scholar
    • Export Citation
  • von Storch, H., E. Zorita, J. M. Jones, Y. Dimitriev, F. González-Rouco, and S. F. B. Tett, 2004: Reconstructing past climate from noisy data. Science, 306 , 679682.

    • Search Google Scholar
    • Export Citation
  • von Storch, H., E. Zorita, J. M. Jones, F. González-Rouco, and S. F. B. Tett, 2006: Response to comment on “Reconstructing past climate from noisy data”. Science, 312 , 529c.

    • Search Google Scholar
    • Export Citation
  • Wessel, P., and W. H. F. Smith, 1991: Free software helps map and display data. Eos, Trans. Amer. Geophys. Union, 72 , 441. doi:10.1029/90EO00319.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 160 51 5
PDF Downloads 111 55 20