Statistical framework for evaluation of climate model simulations by use of climate proxy data from the last millennium – Part 3: Practical considerations, relaxed assumptions, and using tree-ring data to address the amplitude of solar forcing

Abstract. A statistical framework for evaluation of climate model simulations by comparison with climate observations from instrumental and proxy data (part 1 in this series) is improved by the relaxation of two assumptions. This allows autocorrelation in the statistical model for simulated internal climate variability and enables direct comparison of two alternative forced simulations to test whether one fits the observations significantly better than the other. The extended framework is applied to a set of simulations driven with forcings for the pre-industrial period 1000–1849 CE and 15 tree-ring-based temperature proxy series. Simulations run with only one external forcing (land use, volcanic, small-amplitude solar, or large-amplitude solar) do not significantly capture the variability in the tree-ring data – although the simulation with volcanic forcing does so for some experiment settings. When all forcings are combined (using either the small- or large-amplitude solar forcing), including also orbital, greenhouse-gas and non-volcanic aerosol forcing, and additionally used to produce small simulation ensembles starting from slightly different initial ocean conditions, the resulting simulations are highly capable of capturing some observed variability. Nevertheless, for some choices in the experiment design, they are not significantly closer to the observations than when unforced simulations are used, due to highly variable results between regions. It is also not possible to tell whether the small-amplitude or large-amplitude solar forcing causes the multiple-forcing simulations to be closer to the reconstructed temperature variability. Proxy data from more regions and of more types, or representing larger regions and complementary seasons, are apparently needed for more conclusive results from model–data comparisons in the last millennium.

[1]  A. Moberg,et al.  Prediction intervals for climate reconstructions with autocorrelated noise : An analysis of ordinary least squares and measurement error methods , 2011 .

[2]  Edward R. Cook,et al.  The 'segment length curse' in long tree-ring chronology development for palaeoclimatic studies , 1995 .

[3]  P. Jones,et al.  Uncertainty estimates in regional and global observed temperature changes: A new data set from 1850 , 2006 .

[4]  K. Briffa,et al.  Large-scale temperature inferences from tree rings: a review , 2004 .

[5]  K. Briffa,et al.  Trends in recent temperature and radial tree growth spanning 2000 years across northwest Eurasia , 2008, Philosophical Transactions of the Royal Society B: Biological Sciences.

[6]  P. Jones,et al.  Quantifying uncertainties in global and regional temperature change using an ensemble of observational estimates: The HadCRUT4 data set , 2012 .

[7]  J. Hansen,et al.  GLOBAL SURFACE TEMPERATURE CHANGE , 2010 .

[8]  P. Jones,et al.  Adjusting variance for sample-size in tree-ring chronologies and other regional-mean timeseries , 1997 .

[9]  E. Cook,et al.  Tree-ring reconstructed summer temperature anomalies for temperate East Asia since 800 C.E. , 2013, Climate Dynamics.

[10]  Caspar M. Ammann,et al.  Climate forcing reconstructions for use in PMIP simulations of the last millennium (v1.0) , 2011 .

[11]  H. Fritts,et al.  Tree Rings and Climate. , 1978 .

[12]  G. Jacoby,et al.  On the long‐term context for late twentieth century warming , 2006 .

[13]  E. Cook,et al.  Evidence for a ‘Medieval Warm Period’ in a 1,100 year tree‐ring reconstruction of past austral summer temperatures in New Zealand , 2002 .

[14]  S. Solanki,et al.  Reconstruction of solar total irradiance since 1700 from the surface magnetic flux , 2007 .

[15]  C. Ginzler,et al.  Filling the Eastern European gap in millennium-long temperature reconstructions , 2013, Proceedings of the National Academy of Sciences.

[16]  Mike Lockwood,et al.  SOLAR INFLUENCES ON CLIMATE , 2009 .

[17]  E. Mosley‐Thompson,et al.  High-resolution palaeoclimatology of the last millennium: a review of current status and future prospects , 2009 .

[18]  T. Swetnam,et al.  Dendroclimatology : progress and prospects , 2011 .

[19]  Eugene R. Wahl,et al.  Last Millennium Climate and Its Variability in CCSM4 , 2013 .

[20]  K. Briffa,et al.  Reassessing the evidence for tree-growth and inferred temperature change during the Common Era in Yamalia, northwest Siberia , 2013 .

[21]  M. Kawamiya,et al.  Set-up of the PMIP3 paleoclimate experiments conducted using an Earth system model, MIROC-ESM , 2012 .

[22]  E. Zorita,et al.  Large-scale temperature response to external forcing in simulations and reconstructions of the last millennium , 2012 .

[23]  Rolf Sundberg,et al.  Statistical framework for evaluation of climate model simulations by use of climate proxy data from the last millennium – Part 2: A pseudo-proxy study addressing the amplitude of solar forcing , 2012 .

[24]  E. Cook,et al.  Millennia‐long tree‐ring records from Tasmania and New Zealand: a basis for modelling climate variability and forcing, past, present and future , 2006 .

[25]  Gavin A. Schmidt,et al.  Enhancing the relevance of palaeoclimate model/data comparisons for assessments of future climate change , 2010 .

[26]  Heinrich Widmann,et al.  Climate and carbon-cycle variability over the last millennium , 2010 .

[27]  Scott St. George,et al.  The imprint of climate within Northern Hemisphere trees , 2014 .

[28]  Rolf Sundberg,et al.  Statistical framework for evaluation of climate model simulations by use of climate proxy data from the last millennium - Part 1: Theory , 2012 .

[29]  Thomas M. Smith,et al.  Improvements to NOAA’s Historical Merged Land–Ocean Surface Temperature Analysis (1880–2006) , 2008 .

[30]  K. Hasselmann.  Stochastic climate models Part I. Theory , 1976 .

[31]  Eduardo Zorita,et al.  European summer temperature response to annually dated volcanic eruptions over the past nine centuries , 2013, Bulletin of Volcanology.

[32]  D. Frank,et al.  Summer temperature variations in the European Alps, A.D. 755-2004 , 2006 .

[33]  C. Zweck,et al.  Cycles and shifts: 1,300 years of multi-decadal temperature variability in the Gulf of Alaska , 2007 .

[34]  P. Yiou,et al.  Influence of solar variability, CO 2 and orbital forcing between 1000 and 1850 AD in the IPSLCM4 model , 2010 .

[35]  David Frank,et al.  Orbital forcing of tree-ring data , 2012 .

[36]  J. Jouzel,et al.  Solar irradiance during the last 1200 years based on cosmogenic nuclides , 2000 .

[37]  P. Imkeller,et al.  Stochastic climate models , 2001 .

[38]  M. Hughes.  Dendrochronology in climatology – the state of the art , 2002 .

[39]  Thomas M. Melvin,et al.  A “signal-free” approach to dendroclimatic standardisation , 2008 .

[40]  Fritz H. Schweingruber,et al.  Fennoscandian summers from ad 500: temperature changes on short and long timescales , 1992 .

[41]  B. Luckman,et al.  Summer temperatures in the Canadian Rockies during the last millennium: a revised record , 2005 .

[42]  Jörg Franke,et al.  Spectral biases in tree-ring climate proxies , 2013 .

[43]  N. Graham,et al.  Continental-scale temperature variability during the past two millennia , 2013 .

[44]  Thomas M. Melvin,et al.  CRUST: Software for the implementation of Regional Chronology Standardisation: Part 1. Signal-Free RCS , 2014 .

[45]  M. Lockwood.  Solar physics: Shining a light on solar impacts , 2011 .

[46]  E. Cook,et al.  Tree-Ring-Reconstructed Summer Temperatures from Northwestern North America during the Last Nine Centuries , 2013 .

[47]  D. Frank,et al.  Tree growth and inferred temperature variability at the North American Arctic treeline , 2009 .

[48]  P. Jones,et al.  Cool North European summers and possible links to explosive volcanic eruptions , 2013 .

[49]  R. Knutti,et al.  Spatial-Scale Dependence of Climate Model Performance in the CMIP3 Ensemble , 2011 .

[50]  Valerie Trouet,et al.  KNMI Climate Explorer: A Web-Based Research Tool for High-Resolution Paleoclimatology , 2013 .

[51]  M. R. Allen,et al.  Checking for model consistency in optimal fingerprinting , 1999 .

[52]  Michael Schulz,et al.  Information from paleoclimate archives , 2013 .

[53]  Bo Li,et al.  Technical Note: Correcting for signal attenuation from noisy proxy data in climate reconstructions , 2010 .

[54]  Steven J. Phipps,et al.  Paleoclimate Data–Model Comparison and the Role of Climate Forcings over the Past 1500 Years* , 2013 .

[55]  Amy H. Butler,et al.  On the lack of stratospheric dynamical variability in low‐top versions of the CMIP5 models , 2013 .

[56]  Steven J. Phipps,et al.  Separating Forced from Chaotic Climate Variability over the Past Millennium , 2013 .

[57]  H. Goosse,et al.  The role of forcing and internal dynamics in explaining the “Medieval Climate Anomaly” , 2011, Climate Dynamics.

[58]  G. Hegerl,et al.  Influence of human and natural forcing on European seasonal temperatures , 2011 .

[59]  A. Moberg,et al.  Past millennial solar forcing magnitude , 2013, Climate Dynamics.

[60]  K. Anchukaitis,et al.  Volcanic cooling signal in tree ring temperature records for the past millennium , 2013 .

[61]  U. Cubasch,et al.  Mid- to Late Holocene climate change: an overview , 2008 .

[62]  Gwilym M. Jenkins,et al.  Time series analysis, forecasting and control , 1972 .

[63]  Martin Wilmking,et al.  Identification of linear relationships from noisy data using errors-in-variables models—relevance for reconstruction of past climate from tree-ring and other proxy information , 2009 .

[64]  G. Hegerl,et al.  Small influence of solar variability on climate over the past millennium , 2014 .

[65]  Hugues Goosse,et al.  Using data assimilation to study extratropical Northern Hemisphere climate over the last millennium , 2009 .

[66]  G. Hegerl,et al.  Climate sensitivity constrained by temperature reconstructions over the past seven centuries , 2006, Nature.

[67]  E. Zorita,et al.  Estimating 750 years of temperature variations and uncertainties in the Pyrenees by tree-ring reconstructions and climate simulations , 2012 .

[68]  E. Cook,et al.  Warm-season temperatures since 1600 BC reconstructed from Tasmanian tree rings and their relationship to large-scale sea surface temperature anomalies , 2000 .

[69]  G. Hegerl,et al.  Detection of Human Influence on a New, Validated 1500-Year Temperature Reconstruction , 2007 .

[70]  P. Kushner,et al.  Modeling and understanding persistence of climate variability , 2012 .

[71]  R. Quentin Grafton,et al.  global surface temperature , 2012 .

[72]  K. Briffa,et al.  Potential bias in ‘updating’ tree-ring chronologies using regional curve standardisation: Re-processing 1500 years of Torneträsk density and ring-width data , 2013 .

[73]  H. Linderholm,et al.  Improving a tree-ring reconstruction from west-central Scandinavia: 900 years of warm-season temperatures , 2011 .

[74]  Gwilym M. Jenkins,et al.  Time series analysis, forecasting and control , 1971 .