Articles | Volume 15, issue 4
https://doi.org/10.5194/cp-15-1251-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/cp-15-1251-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
05 Jul 2019
Research article |
| 05 Jul 2019
| 05 Jul 2019
Last Millennium Reanalysis with an expanded proxy database and seasonal proxy modeling
Robert Tardif
CORRESPONDING AUTHOR
Department of Atmospheric Sciences, University of Washington, Seattle, WA, USA
Gregory J. Hakim
Department of Atmospheric Sciences, University of Washington, Seattle, WA, USA
Walter A. Perkins
Department of Atmospheric Sciences, University of Washington, Seattle, WA, USA
Kaleb A. Horlick
College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, USA
Michael P. Erb
School of Earth and Sustainability, Northern Arizona University, Flagstaff, AZ, USA
Julien Emile-Geay
Department of Earth Sciences, University of Southern California, Los Angeles, CA, USA
David M. Anderson
Retired, NOAA Paleoclimatology Program, Boulder, CO, USA
Eric J. Steig
Department of Earth and Space Sciences, University of Washington, Seattle, WA, USA
Department of Atmospheric Sciences, University of Washington, Seattle, WA, USA
David Noone
College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, USA
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Nicholas P. McKay and Julien Emile-Geay
Clim. Past, 12, 1093–1100, https://doi.org/10.5194/cp-12-1093-2016, https://doi.org/10.5194/cp-12-1093-2016, 2016
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J. Emile-Geay and M. Tingley
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Ignoring nonlinearity in palaeoclimate records (e.g. continental run-off proxies) runs the risk of severely overstating changes in climate variability. Even with the correct model and parameters, some information is irretrievably lost by such proxies. However, we find that a simple empirical transform can do much to improve the situation, and makes them amenable to classical analyses. Doing so on two palaeo-ENSO records markedly changes some of the quantitative inferences made from such records.
C. Buizert, K. M. Cuffey, J. P. Severinghaus, D. Baggenstos, T. J. Fudge, E. J. Steig, B. R. Markle, M. Winstrup, R. H. Rhodes, E. J. Brook, T. A. Sowers, G. D. Clow, H. Cheng, R. L. Edwards, M. Sigl, J. R. McConnell, and K. C. Taylor
Clim. Past, 11, 153–173, https://doi.org/10.5194/cp-11-153-2015, https://doi.org/10.5194/cp-11-153-2015, 2015
L. Geng, J. Cole-Dai, B. Alexander, J. Erbland, J. Savarino, A. J. Schauer, E. J. Steig, P. Lin, Q. Fu, and M. C. Zatko
Atmos. Chem. Phys., 14, 13361–13376, https://doi.org/10.5194/acp-14-13361-2014, https://doi.org/10.5194/acp-14-13361-2014, 2014
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E. J. Steig, V. Gkinis, A. J. Schauer, S. W. Schoenemann, K. Samek, J. Hoffnagle, K. J. Dennis, and S. M. Tan
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B. Medley, I. Joughin, B. E. Smith, S. B. Das, E. J. Steig, H. Conway, S. Gogineni, C. Lewis, A. S. Criscitiello, J. R. McConnell, M. R. van den Broeke, J. T. M. Lenaerts, D. H. Bromwich, J. P. Nicolas, and C. Leuschen
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E. D. Sofen, B. Alexander, E. J. Steig, M. H. Thiemens, S. A. Kunasek, H. M. Amos, A. J. Schauer, M. G. Hastings, J. Bautista, T. L. Jackson, L. E. Vogel, J. R. McConnell, D. R. Pasteris, and E. S. Saltzman
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Clim. Past, 10, 825–841, https://doi.org/10.5194/cp-10-825-2014, https://doi.org/10.5194/cp-10-825-2014, 2014
J. Wang, J. Emile-Geay, D. Guillot, J. E. Smerdon, and B. Rajaratnam
Clim. Past, 10, 1–19, https://doi.org/10.5194/cp-10-1-2014, https://doi.org/10.5194/cp-10-1-2014, 2014
Related subject area
Subject: Proxy Use-Development-Validation | Archive: Terrestrial Archives | Timescale: Decadal-Seasonal
Hydroclimate extreme events detected by a sub-decadal diatom oxygen isotope record of the last 220 years from Lake Khamra, Siberia
Large-scale climate signals of a European oxygen isotope network from tree rings
The response of annual minimum temperature on the eastern central Tibetan Plateau to large volcanic eruptions over the period 1380–2014 CE
Introduction to the special issue “Climate of the past 2000 years: regional and trans-regional syntheses”
Arctic hydroclimate variability during the last 2000 years: current understanding and research challenges
French summer droughts since 1326 CE: a reconstruction based on tree ring cellulose δ18O
A 500-year seasonally resolved δ18O and δ13C, layer thickness and calcite aspect record from a speleothem deposited in the Han-sur-Lesse cave, Belgium
Monitoring of a fast-growing speleothem site from the Han-sur-Lesse cave, Belgium, indicates equilibrium deposition of the seasonal δ18O and δ13C signals in the calcite
Variation in the Asian monsoon intensity and dry–wet conditions since the Little Ice Age in central China revealed by an aragonite stalagmite
Millennial minimum temperature variations in the Qilian Mountains, China: evidence from tree rings
Tree-ring-inferred glacier mass balance variation in southeastern Tibetan Plateau and its linkage with climate variability
Bayesian parameter estimation and interpretation for an intermediate model of tree-ring width
Modern isotope hydrology and controls on δD of plant leaf waxes at Lake El'gygytgyn, NE Russia
Clustering climate reconstructions
Extracting a common high frequency signal from Northern Quebec black spruce tree-rings with a Bayesian hierarchical model
Amelie Stieg, Boris K. Biskaborn, Ulrike Herzschuh, Jens Strauss, Luidmila Pestryakova, and Hanno Meyer
Clim. Past Discuss., https://doi.org/10.5194/cp-2023-85, https://doi.org/10.5194/cp-2023-85, 2023
Revised manuscript accepted for CP
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Siberia is impacted by recent climate warming and experiences extreme hydroclimate events. We present a 220 year long sub-decadal stable oxygen isotope record of diatoms from Lake Khamra. Our analysis identifies winter precipitation as the key process impacting the isotope variability, highlighting two extreme dry periods. These two events were found to coincide with significant changes in lake internal conditions and increased wildfire activity in the region.
Daniel F. Balting, Monica Ionita, Martin Wegmann, Gerhard Helle, Gerhard H. Schleser, Norel Rimbu, Mandy B. Freund, Ingo Heinrich, Diana Caldarescu, and Gerrit Lohmann
Clim. Past, 17, 1005–1023, https://doi.org/10.5194/cp-17-1005-2021, https://doi.org/10.5194/cp-17-1005-2021, 2021
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To extend climate information back in time, we investigate the climate sensitivity of a δ18O network from tree rings, consisting of 26 European sites and covering the last 400 years. Our results suggest that the δ18O variability is associated with large-scale anomaly patterns that resemble those observed for the El Niño–Southern Oscillation. We conclude that the investigation of large-scale climate signals far beyond instrumental records can be done with a δ18O network derived from tree rings.
Yajun Wang, Xuemei Shao, Yong Zhang, and Mingqi Li
Clim. Past, 17, 241–252, https://doi.org/10.5194/cp-17-241-2021, https://doi.org/10.5194/cp-17-241-2021, 2021
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It is not clear to what extent or in what manner a strong volcanic eruption will influence temperature in different regions over the long term. Therefore, new 635-year annual mean minimum temperatures (Tmin) across the eastern central Tibetan Plateau were used to explored the response of Tmin to strong volcanic eruptions. Our results show that there is a high probability that the Tmin decreases within 2 years of a large volcanic eruption, especially when such eruptions occur in low latitudes.
Chris S. M. Turney, Helen V. McGregor, Pierre Francus, Nerilie Abram, Michael N. Evans, Hugues Goosse, Lucien von Gunten, Darrell Kaufman, Hans Linderholm, Marie-France Loutre, and Raphael Neukom
Clim. Past, 15, 611–615, https://doi.org/10.5194/cp-15-611-2019, https://doi.org/10.5194/cp-15-611-2019, 2019
Short summary
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This PAGES (Past Global Changes) 2k (climate of the past 2000 years working group) special issue of Climate of the Past brings together the latest understanding of regional change and impacts from PAGES 2k groups across a range of proxies and regions. The special issue has emerged from a need to determine the magnitude and rate of change of regional and global climate beyond the timescales accessible within the observational record.
Hans W. Linderholm, Marie Nicolle, Pierre Francus, Konrad Gajewski, Samuli Helama, Atte Korhola, Olga Solomina, Zicheng Yu, Peng Zhang, William J. D'Andrea, Maxime Debret, Dmitry V. Divine, Björn E. Gunnarson, Neil J. Loader, Nicolas Massei, Kristina Seftigen, Elizabeth K. Thomas, Johannes Werner, Sofia Andersson, Annika Berntsson, Tomi P. Luoto, Liisa Nevalainen, Saija Saarni, and Minna Väliranta
Clim. Past, 14, 473–514, https://doi.org/10.5194/cp-14-473-2018, https://doi.org/10.5194/cp-14-473-2018, 2018
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This paper reviews the current knowledge of Arctic hydroclimate variability during the past 2000 years. We discuss the current state, look into the future, and describe various archives and proxies used to infer past hydroclimate variability. We also provide regional overviews and discuss the potential of furthering our understanding of Arctic hydroclimate in the past. This paper summarises the hydroclimate-related activities of the Arctic 2k group.
Inga Labuhn, Valérie Daux, Olivier Girardclos, Michel Stievenard, Monique Pierre, and Valérie Masson-Delmotte
Clim. Past, 12, 1101–1117, https://doi.org/10.5194/cp-12-1101-2016, https://doi.org/10.5194/cp-12-1101-2016, 2016
Short summary
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This article presents a reconstruction of summer droughts in France for the last 680 years, based on oxygen isotope ratios in tree ring cellulose from living trees and building timbers at two sites, Fontainebleau and Angoulême. Both sites show coherent drought patterns during the 19th and 20th century, and are characterized by increasing drought in recent decades. A decoupling between sites points to a more heterogeneous climate in France during earlier centuries.
M. Van Rampelbergh, S. Verheyden, M. Allan, Y. Quinif, H. Cheng, L. R. Edwards, E. Keppens, and P. Claeys
Clim. Past, 11, 789–802, https://doi.org/10.5194/cp-11-789-2015, https://doi.org/10.5194/cp-11-789-2015, 2015
M. Van Rampelbergh, S. Verheyden, M Allan, Y. Quinif, E. Keppens, and P. Claeys
Clim. Past, 10, 1871–1885, https://doi.org/10.5194/cp-10-1871-2014, https://doi.org/10.5194/cp-10-1871-2014, 2014
J.-J. Yin, D.-X. Yuan, H.-C. Li, H. Cheng, T.-Y. Li, R. L. Edwards, Y.-S. Lin, J.-M. Qin, W. Tang, Z.-Y. Zhao, and H.-S. Mii
Clim. Past, 10, 1803–1816, https://doi.org/10.5194/cp-10-1803-2014, https://doi.org/10.5194/cp-10-1803-2014, 2014
Y. Zhang, X. M. Shao, Z.-Y. Yin, and Y. Wang
Clim. Past, 10, 1763–1778, https://doi.org/10.5194/cp-10-1763-2014, https://doi.org/10.5194/cp-10-1763-2014, 2014
J. Duan, L. Wang, L. Li, and Y. Sun
Clim. Past, 9, 2451–2458, https://doi.org/10.5194/cp-9-2451-2013, https://doi.org/10.5194/cp-9-2451-2013, 2013
S. E. Tolwinski-Ward, K. J. Anchukaitis, and M. N. Evans
Clim. Past, 9, 1481–1493, https://doi.org/10.5194/cp-9-1481-2013, https://doi.org/10.5194/cp-9-1481-2013, 2013
K. M. K. Wilkie, B. Chapligin, H. Meyer, S. Burns, S. Petsch, and J. Brigham-Grette
Clim. Past, 9, 335–352, https://doi.org/10.5194/cp-9-335-2013, https://doi.org/10.5194/cp-9-335-2013, 2013
G. Bürger
Clim. Past, 6, 515–523, https://doi.org/10.5194/cp-6-515-2010, https://doi.org/10.5194/cp-6-515-2010, 2010
J.-J. Boreux, P. Naveau, O. Guin, L. Perreault, and J. Bernier
Clim. Past, 5, 607–613, https://doi.org/10.5194/cp-5-607-2009, https://doi.org/10.5194/cp-5-607-2009, 2009
Cited articles
Acevedo, W., Fallah, B., Reich, S., and Cubasch, U.: Assimilation of
pseudo-tree-ring-width observations into an atmospheric general circulation
model, Clim. Past, 13, 545–557, https://doi.org/10.5194/cp-13-545-2017, 2017. a, b
Bhend, J., Franke, J., Folini, D., Wild, M., and Brönnimann, S.: An
ensemble-based approach to climate reconstructions, Clim. Past, 8, 963–976,
https://doi.org/10.5194/cp-8-963-2012, 2012. a
Briffa, K. R., Osborn, T. J., and Schweingruber, F. H.: Large-scale temperature
inferences from tree rings: a review, Glob. Planet. Change, 40, 11–26,
https://doi.org/10.1016/S0921-8181(03)00095-X, 2004. a
Cobb, K. M., Charles, C. D., Cheng, H., and Edwards, R. L.: El Niño –
Southern Oscillation and tropical Pacific climate during the last millennium,
Nature, 424, 271–276, https://doi.org/10.1038/nature01779, 2003. a
Compo, G., Whitaker, J., Sardeshmukh, P., Matsui, N., Allan, R., Yin, A.,
Gleason, B., Vose, R., Rutledge, G., Bessemoulin, P., Brönnimann, S.,
Brunet, M., Crouthamel, R., Grant, A., Groisman, P., Jones, P., Kruk, M.,
Kruger, A., Marshall, G., Maugeri, M., Mok, H., Nordli, Ø., Ross, T.,
Trigo, R., Wang, X., Woodruff, S., and Worley, S.: The twentieth century
reanalysis project, Q. J. Roy. Meteor. Soc.,
137, 1–28, https://doi.org/10.1002/qj.776, 2011. a, b, c
Dai, A.: Characteristics and trends in various forms of the palmer drought
severity index during 1900–2008, J. Geophys. Res.-Atmos., 116, 1–26, https://doi.org/10.1029/2010JD015541, 2011. a, b, c
D'Arrigo, R., Mashig, E., Frank, D., Wilson, R., and Jacoby, G.: Temperature
variability over the past millennium inferred from Northwestern Alaska
tree rings, Clim. Dynam., 44, 227–236, https://doi.org/10.1007/s00382-004-0502-1, 2005. a
D'Arrigo, R., Anchukaitis, K. J., Buckley, B., Cook, E., and Wilson, R.:
Regional climatic and North Atlantic Oscillation signatures in West Virginia
red cedar over the past millennium, Glob. Planet. Change, 84/85,
8–13, https://doi.org/10.1016/j.gloplacha.2011.07.003, 2012. a
Dee, S., Emile-Geay, J., Evans, M. N., Allam, A., Steig, E. J., and Thompson,
D. M.: PRYSM: An open-source framework for PRoxY System Modeling, with
applications to oxygen-isotope systems, J. Adv. Model. Earth
Sy., 7, 1220–1247, https://doi.org/10.1002/2015MS000447, 2015. a
Dee, S., Steiger, N. J., Emile-Geay, J., and Hakim, Gregory J.: The utility
of proxy system modeling in estimating climate states over the Common Era,
J. Adv. Model. Earth Sy., 8, 1164–1179,
https://doi.org/10.1002/2016MS000677, 2016. a, b, c, d
Department of Atmospheric Sciences: Last Millennium Reanalysis (LMR) Project Data, available at: https://atmos.washington.edu/~hakim/LMR/, 26 June 2019.
Diaz, H. F., Trigo, R., Hughes, M. K., Mann, M. E., Xoplaki, E., and
Barriopedro, D.: Spatial and temporal characteristics of the climate in
medieval times revisited, Bull. Am. Meteorol. Soc.,
99, 1487–1500, https://doi.org/10.1175/BAMS-D-10-05003.1, 2011. a
Emile-Geay, J., Cobb, K. M., Mann, M. E., and Wittenberg, A. T.: Estimating
central equatorial Pacific SST variability over the past millennium. Part I:
Methodology and validation, J. Clim., 26, 2302–2328, 2013. a
Evans, M. N., Tolwinski-Ward, S. E., Thompson, D. M., and Anchukaitis, K. J.:
Applications of proxy system modeling in high resolution paleoclimatology,
Quaternary Sci. Rev., 76, 16–28, 2013. a
Evensen, G.: The ensemble Kalman filter: Theoretical formulation and practical
implementation, Ocean Dynam., 53, 343–367, 2003. a
Franke, J., Brönnimann, S., Bhend, J., and Brugnara, Y.: A monthly global
paleo-reanalysis of the atmosphere from 1600 to 2005 for studying past
climatic variations, Sci. Data, 4, 170076, https://doi.org/10.1038/sdata.2017.76, 2017. a
Gaspari, G. and Cohn, S. E.: Construction of correlation functions in two and
three dimensions, Q. J. Roy. Meteor. Soc., 125, 723–757,
https://doi.org/10.1002/qj.49712555417, 1999. a
Goldberger, A. S.: Econometric Theory, Wiley, New York, NY, 1964. a
Goosse, H.: An additional step toward comprehensive paleoclimate reanalyses,
J. Adv. Model. Earth Syst., 8, 1501–1503,
https://doi.org/10.1002/2016MS000739, 2016. a
Goosse, H., Renssen, H., Timmermann, A., Bradley, R. S., and Mann, M. E.: Using
paleoclimate proxy-data to select optimal realisations in an ensemble of
simulations of the climate of the past millennium, Clim. Dynam., 27,
165–184, https://doi.org/10.1007/s00382-006-0128-6, 2006. a
Goosse, H., E., C., de Montety, A., Mann, M. E., Renssen, H., and Timmermann,
A.: Reconstructing surface temperature changes over the past 600 years using
climate model simulations with data assimilation, J. Geophys. Res.-Atmos.,
115, D09108, https://doi.org/10.1029/2009jd012737, 2010. a
Hakim, G. J.: Source code for the Last Millennium Reanalysis (LMR)
project, available at: https://github.com/modons/LMR, last access: 30 June 2019a.
Hakim, G. J. : Last Millennium Reanalysis (LMR) Project Data, available at: https://atmos.washington.edu/~hakim/lmr/, https://doi.org/10.17911/S9WC7N, last access 30 June 2019b.
Hamill, T. M., Whitaker, J. S., and Snyder, C.: Distance-dependent filtering of
background error covariance estimates in an ensemble Kalman filter, Mon.
Weather Rev., 129, 2776–2790,
https://doi.org/10.1175/1520-0493(2001)129<2776:DDFOBE>2.0.CO;2, 2001. a, b
Hansen, J., Ruedy, R., Sato, M., and Lo, K.: Global surface temperature change,
Rev. Geophys., 48, RG4004, https://doi.org/10.1029/2010RG000345, 2010. a, b
Juckes, M. N., Allen, M. R., Briffa, K. R., Esper, J., Hegerl, G. C., Moberg,
A., Osborn, T. J., and Weber, S. L.: Millennial temperature reconstruction
intercomparison and evaluation, Clim. Past, 3, 591–609,
https://doi.org/10.5194/cp-3-591-2007, 2007. a
Landrum, L., Otto-Bliesner, B. L., Wahl, E. R., Conley, A., Lawrence, P. J.,
Rosenbloom, N., and Teng, H.: Last millennium climate and its variability in
CCSM4, J. Clim., 26, 1085–1111, https://doi.org/10.1175/JCLI-D-11-00326.1,
2013. a
Liu, H., Liu, Z., and Lu, F.: A systematic comparison of particle filter and
EnKF in assimilating time–averaged observations, J. Geophys.
Res.-Atmos., 122, 13155–13173, https://doi.org/10.1002/2017JD026798, 2017. a
Mann, M. E. and Jones, P. D.: Global surface temperatures over the past two
millennia, Geophys. Res. Lett., 30, 1820, https://doi.org/10.1029/2003GL017814,
2003. a
Mann, M. E., Bradley, R. S., and Hughes, M. K.: Northern hemisphere
temperatures during the past millennium: Inferences, uncertainties, and
limitations, Geophys. Res. Lett., 26, 759–762,
https://doi.org/10.1029/1999GL900070, 1999. a
Mann, M. E., Zhang, Z., Hughes, M. K., Bradley, R. S., Miller, S. K.,
Rutherford, S., and Ni, F.: Proxy-based reconstructions of hemispheric and
global surface temperature variations over the past two millennia,
P. Natl. Acad. Sci. USA, 105, 13252–13257,
https://doi.org/10.1073/pnas.0805721105, 2008. a
Mann, M. E., Zhang, Z., Rutherford, S., Bradley, R. S., Hughes, M. K.,
Shindell, D., Ammann, C., Faluvegi, G., and F., N.: Global signatures and
dynamical origins of the Little Ice Age and Medieval Climate Anomaly,
Science, 326, 1256–1260, https://doi.org/10.1126/science.1177303, 2009. a
Matsikaris, A., Widmann, M., and Jungclaus, J. H.: On-line and off-line data
assimilation in palaeoclimatology: a case study, Clim. Past, 11, 81–93,
https://doi.org/10.5194/cp-11-81-2015, 2015. a, b, c
Moberg, A., Sonechkin, D. M., Holmgren, K., Datsenko, N. M., and Karlén,
W.: Highly variable Northern Hemisphere temperatures reconstructed from low-
and high-resolution proxy data, Nature, 433, 613–617, 2005. a
Morice, C. P., Kennedy, J. J., Rayner, N. A., and Jones, P. D.: Quantifying
uncertainties in global and regional temperature change using an ensemble of
observational estimates: the HadCRUT4 dataset, J. Geophys.
Res.-Atmos., 117, D08101, https://doi.org/10.1029/2011JD017187, 2012. a
Murphy, J. M.: The impact of ensemble forecasts on predictability, Q. J.
Roy. Meteor. Soc., 114, 463–493, https://doi.org/10.1002/qj.49711448010, 1988. a
Nash, J. E. and Sutcliffe, J. V.: River flow forecasting through conceptual
models part I – A discussion of principles, J. Hydrol., 10,
282–290, 1970. a
Okazaki, A. and Yoshimura, K.: Development and evaluation of a system of proxy
data assimilation for paleoclimate reconstruction, Clim. Past, 13, 379–393,
https://doi.org/10.5194/cp-13-379-2017, 2017. a
Oke, P., Schiller, A., Griffin, D. A., and Brassington, G. B.: Ensemble data
assimilation for an eddy-resolving ocean model of the Australian region,
Q. J. Roy. Meteor. Soc., 131, 3301–3311,
https://doi.org/10.1256/qj.05.95, 2005. a
Oke, P. R., Allen, J. S., Miller, R. N., Egbert, G. D., and Kosro, P. M.:
Assimilation of surface velocity data into a primitive equation coastal ocean
model, J. Geophys. Res.-Ocean., 107, 3122,
https://doi.org/10.1029/2000JC000511, 2002. a
Oke, P. R., Sakov, P., and Corney, S. P.: Impacts of localisation in the EnKF
and EnOI: experiments with a small model, Ocean Dynam., 57, 32–45,
https://doi.org/10.1007/s10236-006-0088-8, 2007. a
PAGES 2k Consortium: Continental-scale temperature variability during
the past two millennia, Nat. Geosci., 6, 339–346,
https://doi.org/10.1038/ngeo1834, 2013. a, b, c, d
Perkins, W. A. and Hakim, G. J.: Reconstructing paleoclimate fields using
online data assimilation with a linear inverse model, Clim. Past, 13,
421–436, https://doi.org/10.5194/cp-13-421-2017, 2017. a, b
Poli, P., Hersbach, H., and Dee, D. P.: ERA-20C: An atmospheric reanalysis of
the twentieth century, J. Clim., 29, 4083–4097,
https://doi.org/10.1175/JCLI-D-15-0556.1, 2016. a, b
Pollack, H. N. and Smerdon, J. E.: Borehole climate reconstructions: Spatial
structure and hemispheric averages, J. Geophys. Res., 109, D11106,
https://doi.org/10.1029/2003JD004163, 2004. a, b
Rohde, R., Muller, R., Jacobsen, R., Perlmutter, S., Rosenfeld, A., Wurtele,
J., Curry, J., Wickman, C., and Mosher, S.: Berkeley Earth temperature
averaging process, Geoinformatics and Geostatistics: An Overview, 1, 1–13,
https://doi.org/10.4172/2327-4581.1000103, 2013. a, b, c
Rutherford, S., M. E. Mann, M. E., Osborn, T. J., Bradley, R. S., Briffa,
K. R., Hughes, M. K., and Jones, P. D.: Proxy-based Northern Hemisphere
surface temperature reconstructions: Sensitivity to method, predictor
network, target season, and target domain, J. Clim., 18,
2308–2329, https://doi.org/10.1175/JCLI3351.1, 2005. a
Sano, M., Furuta, F., and Sweda, T.: Tree-ring-width chronology of Larix
gmelinii as an indicator of changes in early summer temperature in
east-central Kamchatka, J. Forest Res., 14, 147–154,
https://doi.org/10.1007/s10310-009-0123-y, 2009. a
Schneider, U., Becker, A., Finger, P., Meyer-Christoffer, A., Ziese, M., and
Rudolf, B.: GPCC's new land surface precipitation climatology based on
quality-controlled in situ data and its role in quantifying the global water
cycle, Theor. Appl. Climatol., 115, 15–40,
https://doi.org/10.1007/s00704-013-0860-x, 2014. a
Schwarz, G. E.: Estimating the dimension of a model, Ann. Stat., 6,
461–464, https://doi.org/10.1214/aos/1176344136, 1978. a
Smith, T. M., Reynolds, R. W., Peterson, T. C., and Lawrimore, J.: Improvements
to NOAA's historical merged land–ocean surface temperature analysis
(1880–2006), J. Clim., 21, 2283–2296,
https://doi.org/10.1175/2007JCLI2100.1, 2008. a
St. George, S.: An overview of tree-ring width records across the Northern
Hemisphere, Quaternary Sci. Rev., 95, 132–150,
https://doi.org/10.1016/j.quascirev.2014.04.029, 2014. a
St. George, S., Meko, D. M., and Cook, E. R.: The seasonality of precipitation
signals embedded within the North American Drought Atlas, The Holocene, 20,
983–988, https://doi.org/10.1177/0959683610365937, 2010.
a
Stahle, D. W., Cleaveland, M. K., Grissino-Mayer, H. D., Griffin, R. D., Fye,
F. K., Therell, M. D., Burnette, D. J., Meko, D. M., and Villanueva Diaz, J.:
Cool- and warm-season precipitation reconstructions over western New
Mexico, J. Clim., 22, 3729–3750, https://doi.org/10.1175/2008JCLI2752.1, 2009. a
Steiger, N. J. and Smerdon, J. E.: A pseudoproxy assessment of data
assimilation for reconstructing the atmosphere–ocean dynamics of
hydroclimate extremes, Clim. Past, 13, 1435–1449,
https://doi.org/10.5194/cp-13-1435-2017, 2017. a
Steiger, N. J., Hakim, G. J., Steig, E. J., Battisti, D. S., and Roe, G. H.:
Assimilation of time-averaged pseudoproxies for climate reconstruction,
J. Clim., 27, 426–441, https://doi.org/10.1175/JCLI-D-12-00693.1, 2014. a
Steiger, N. J., Steig, E. J., Dee, S. G., Roe, G. H., and Hakim, G. J.: Climate
reconstruction using data assimilation of water isotope ratios from ice
cores, J. Geophys. Res.-Atmos., 122, 1545–1568,
https://doi.org/10.1002/2016JD026011, 2017. a
Tardif, R., Hakim, G. J., and Snyder, C.: Coupled atmosphere–ocean data
assimilation experiments with a low-order model and CMIP5 model data, Clim.
Dynam., 45, 1415–1427, 2015. a
Taylor, K. E., Stouffer, R. J., and Meehl, G. A.: An overview of CMIP5 and
the experiment design, Bull. Am. Meteorol. Soc., 93,
485–498, https://doi.org/10.1175/BAMS-D-11-00094.1, 2012. a
Tolwinski-Ward, S. E., Evans, M. N., Hughes, M. K., and Anchukaitis, K. J.: An
efficient forward model of the climate controls on interannnual variation in
tree-ring width, Clim. Dynam., 36, 2419–2439,
https://doi.org/10.1007/s00382-011-1062-9, 2011. a
Touchan, R., Garfin, G., Meko, D., Funkhouser, G., Erkan, N., Hughes, M., and
Wallin, B.: Preliminary reconstructions of spring precipitation in
southwestern Turkey from tree-ring width, Int. J. Climatol., 23, 157–171,
https://doi.org/10.1002/joc.850, 2003. a
Wang, J., Emile-Geay, J., McKay, N. P., and Rajaratnam, B.: Fragility of
reconstructed temperature patterns over the common era: Implications for
model evaluation, Geophys. Res. Lett., 42, 7162–7170,
https://doi.org/10.1002/2015GL065265, 2015. a
Whitaker, J. S. and Hamill, T. M.: Ensemble data assimilation without perturbed
observations, Mon. Weather Rev., 130, 1913–1924,
https://doi.org/10.1175/1520-0493(2002)130<1913:EDAWPO>2.0.CO;2, 2002. a
Widmann, M., Goosse, H., Schrier, G., Schnur, R., and Barkmeijer, J.: Using
data assimilation to study extratropical Northern Hemisphere climate over the
last millennium, Clim. Past, 6, 627–644, https://doi.org/10.5194/cp-6-627-2010, 2010. a
Short summary
An updated Last Millennium Reanalysis is presented, using an expanded multi-proxy database, and proxy models representing the seasonal characteristics of proxy records, in addition to the dual sensitivity to temperature and moisture of tree-ring-width chronologies. We show enhanced skill in spatial reconstructions of key climate variables in the updated reanalysis, compared to an earlier version, resulting from the combined influences of the enhanced proxy network and improved proxy modeling.
An updated Last Millennium Reanalysis is presented, using an expanded multi-proxy database, and...
