Climate Dynamics

, Volume 45, Issue 5, pp 1395–1413

Establishing the skill of climate field reconstruction techniques for precipitation with pseudoproxy experiments

  • Juan José Gómez-Navarro
  • Johannes Werner
  • Sebastian Wagner
  • Jürg Luterbacher
  • Eduardo Zorita
Article

DOI: 10.1007/s00382-014-2388-x

Cite this article as:
Gómez-Navarro, J.J., Werner, J., Wagner, S. et al. Clim Dyn (2015) 45: 1395. doi:10.1007/s00382-014-2388-x

Abstract

This study aims at assessing the skill of several climate field reconstruction techniques (CFR) to reconstruct past precipitation over continental Europe and the Mediterranean at seasonal time scales over the last two millennia from proxy records. A number of pseudoproxy experiments are performed within the virtual reality of a regional paleoclimate simulation at 45 km resolution to analyse different aspects of reconstruction skill. Canonical Correlation Analysis (CCA), two versions of an Analog Method (AM) and Bayesian hierarchical modeling (BHM) are applied to reconstruct precipitation from a synthetic network of pseudoproxies that are contaminated with various types of noise. The skill of the derived reconstructions is assessed through comparison with precipitation simulated by the regional climate model. Unlike BHM, CCA systematically underestimates the variance. The AM can be adjusted to overcome this shortcoming, presenting an intermediate behaviour between the two aforementioned techniques. However, a trade-off between reconstruction-target correlations and reconstructed variance is the drawback of all CFR techniques. CCA (BHM) presents the largest (lowest) skill in preserving the temporal evolution, whereas the AM can be tuned to reproduce better correlation at the expense of losing variance. While BHM has been shown to perform well for temperatures, it relies heavily on prescribed spatial correlation lengths. While this assumption is valid for temperature, it is hardly warranted for precipitation. In general, none of the methods outperforms the other. All experiments agree that a dense and regularly distributed proxy network is required to reconstruct precipitation accurately, reflecting its high spatial and temporal variability. This is especially true in summer, when a specifically short de-correlation distance from the proxy location is caused by localised summertime convective precipitation events.

Keywords

Precipitation Palaeoclimate Climate reconstruction Regional climate modelling Proxy PPE 

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • Juan José Gómez-Navarro
    • 1
    • 2
  • Johannes Werner
    • 3
    • 4
  • Sebastian Wagner
    • 2
  • Jürg Luterbacher
    • 4
  • Eduardo Zorita
    • 2
  1. 1.Physics Institute and Oescher Centre for Climate Change ResearchUniversity of BernBernSwitzerland
  2. 2.Institute for Coastal ResearchHelmholtz-Zentrum GeesthachtGeesthachtGermany
  3. 3.Bjerknes Centre for Climate Research and Department of Earth ScienceUniversity of BergenBergenNorway
  4. 4.Department of Geography, Climatology, Climate Dynamics and Climate ChangeJustus Liebig University of GiessenGiessenGermany

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