@article{6894f91486f0434f8794a7f7b79281c8,
title = "Comparing proxy and model estimates of hydroclimate variability and change over the Common Era",
abstract = "Water availability is fundamental to societies and ecosystems, but our understanding of variations in hydroclimate (including extreme events, flooding, and decadal periods of drought) is limited because of a paucity of modern instrumental observations that are distributed unevenly across the globe and only span parts of the 20th and 21st centuries. Such data coverage is insufficient for characterizing hydroclimate and its associated dynamics because of its multidecadal to centennial variability and highly regionalized spatial signature. High-resolution (seasonal to decadal) hydroclimatic proxies that span all or parts of the Common Era (CE) and paleoclimate simulations from climate models are therefore important tools for augmenting our understanding of hydroclimate variability. In particular, the comparison of the two sources of information is critical for addressing the uncertainties and limitations of both while enriching each of their interpretations. We review the principal proxy data available for hydroclimatic reconstructions over the CE and highlight the contemporary understanding of how these proxies are interpreted as hydroclimate indicators. We also review the available last-millennium simulations from fully coupled climate models and discuss several outstanding challenges associated with simulating hydroclimate variability and change over the CE. A specific review of simulated hydroclimatic changes forced by volcanic events is provided, as is a discussion of expected improvements in estimated radiative forcings, models, and their implementation in the future. Our review of hydroclimatic proxies and last-millennium model simulations is used as the basis for articulating a variety of considerations and best practices for how to perform proxy-model comparisons of CE hydroclimate. This discussion provides a framework for how best to evaluate hydroclimate variability and its associated dynamics using these comparisons and how they can better inform interpretations of both proxy data and model simulations. We subsequently explore means of using proxy-model comparisons to better constrain and characterize future hydroclimate risks. This is explored specifically in the context of several examples that demonstrate how proxy-model comparisons can be used to quantitatively constrain future hydroclimatic risks as estimated from climate model projections.",
author = "{PAGES Hydro2k Consortium} and Smerdon, {Jason E.} and J{\"u}rg Luterbacher and Phipps, {Steven J.} and Anchukaitis, {Kevin J.} and Toby Ault and Sloan Coats and Cobb, {Kim M.} and Cook, {Benjamin I.} and Chris Colose and Thomas Felis and Ailie Gallant and Jungclaus, {Johann H.} and Bronwen Konecky and Allegra LeGrande and Sophie Lewis and Lopatka, {Alex S.} and Wenmin Man and Mankin, {Justin S.} and Maxwell, {Justin T.} and Otto-Bliesner, {Bette L.} and Partin, {Judson W.} and Deepti Singh and Steiger, {Nathan J.} and Tierney, {Jessica E.} and Davide Zanchettin and Huan Zhang and Atwood, {Alyssa R.} and Laia Andreu-Hayles and Baek, {Seung H.} and Brendan Buckley and Cook, {Edward R.} and Rosanne D{\textquoteright}Arrigo and Dee, {Sylvia G.} and Griffiths, {Michael L.} and Charuta Kulkarni and Yochanan Kushnir and Flavio Lehner and Caroline Leland and Atsushi Okazaki and Jonathan Palmer and Eduardo Piovano and Raible, {Christoph C.} and Rao, {Mukund P.} and Jacob Scheff and Schmidt, {Gavin A.} and Richard Seager and Martin Widmann and Jacob Scheff and Elena Xoplaki",
note = "Funding Information: Acknowledgements. This paper reflects findings and discussions from a workshop held at the Lamont-Doherty Earth Observatory of Columbia University on 1–3 June 2016 titled Comparing data and model estimates of hydroclimate variability and change over the Common Era (see http://pages2kpmip3.github.io/ and Smerdon et al., 2016). The PAGES2k and PMIP communities were instrumental in the motivation and conceptualization of the workshop and we gratefully acknowledge funding from PAGES and the La-mont Climate Center. We also acknowledge the workshop for inspiring the establishment of the CoralHydro2k project as part of the PAGES 2k Network (http://www.pastglobalchanges.org/ini/wg/ 2k-network/projects/coral-hydro). We thank the World Climate Research Program{\textquoteright}s Working Group on Coupled Modeling, which oversees CMIP, and the individual model groups (listed in Table 1) for making their data available. Funding Information: Individual researchers on this study were supported in part by the US National Science Foundation through the National Center for Atmospheric Research and the following: grants AGS-1502150, AGS-1303976, AGS-1433551, AGS-1602564, AGS-1501856, AGS-1243125, AGS-1243107, AGS-1404003, AGS-1243204, AGS-1401400, AGS-1602581, AGS-1502830, AGS-1203785, AGS-1602920, and OCE-1502832; Australian Research Council grants SR140300001, FL100100195, and DECRA DE16010092; National Natural Science Foundation of China grant numbers 41305069 and 41675082 and the Jiangsu Collaborative Innovation Center for Climate Change; the German Federal Ministry of Education and Research (BMBF) and JPI-Climate/Belmont Forum projects PACMEDY (FKZ: 01LP1607B) and Collaborative Research Action “INTEGRATE, An integrated data-model study of interactions between tropical monsoons and extratropical climate variability and extremes”; the DFG-Research Center/Cluster of Excellence “The Ocean in the Earth System” at the University of Bremen; the Swedish Science Council (VR) (2012-5246); the Swiss National Science Foundation; the Brown Institute for Environment and Society; the Lamont-Doherty Postdoctoral Fellowship and Earth Institute Postdoctoral Fellowship programs of Columbia University; and the NOAA Climate and Global Change Postdoctoral Fellowship Program administered by the University Corporation for Atmospheric Research Visiting Scientist Program. Publisher Copyright: {\textcopyright} Author(s) 2017. This work is distributed under.",
year = "2017",
month = dec,
day = "20",
doi = "10.5194/cp-13-1851-2017",
language = "English (US)",
volume = "13",
pages = "1851--1900",
journal = "Climate of the Past",
issn = "1814-9324",
publisher = "European Geosciences Union",
number = "12",
}