noaa-recon-19725 Northern Hemisphere hydroclimatic variability over the past twelve centuries Ljungqvist, F.C.; Krusic, P.J.; Sundqvist, H.; Zorita, E.; Brattström; Frank, D.C. Northern Hemisphere hydroclimatic variability over the past twelve centuries 2016-04-07 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/19725 Investigator F.C. Ljungqvist Investigator P.J. Krusic Investigator H. Sundqvist Investigator E. Zorita Investigator Brattström Investigator D.C. Frank earth science paleoclimate climate reconstructions longitude,null,null,degree east,null,climate reconstructions,null,null,N,null earth science paleoclimate climate reconstructions latitude,null,null,degree north,null,climate reconstructions,null,null,N,null earth science paleoclimate climate reconstructions age,null,null,year Common Era,null,climate reconstructions,null,null,N,null earth science paleoclimate climate reconstructions moisture index,multiple proxies,null,standard deviation unit,null,climate reconstructions,anomalized,null,N,null earth science paleoclimate reconstructions precipitation geoscientificInformation Other Hydroclimate Reconstruction Precipitation Reconstruction drought 800 AD 1999 AD 1150 cal yr BP -49 cal yr BP Complete 0 90 -180 180 Geographic Region Northern Hemisphere Northern Hemisphere>LATITUDE >LONGITUDE None Please cite original publication, online resource, dataset and publication DOIs (where available), and date accessed when using downloaded data. If there is no publication information, please cite investigator, title, online resource, and date accessed. The appearance of external links associated with a dataset does not constitute endorsement by the Department of Commerce/National Oceanic and Atmospheric Administration of external Web sites or the information, products or services contained therein. For other than authorized activities, the Department of Commerce/NOAA does not exercise any editorial control over the information you may find at these locations. These links are provided consistent with the stated purpose of this Department of Commerce/NOAA Web site. English DOC/NOAA/NESDIS/NCEI National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce https://www.ncdc.noaa.gov/data-access/paleoclimatology-data DATA Center Contact Bruce Bauer bruce.a.bauer@noaa.gov paleo@noaa.gov 303-497-6280 303-497-6513

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Boulder CO 80305-3328 USA online ASCII Fredrik Charpentier Ljungqvist, Paul J. Krusic, Hanna S. Sundqvist, Eduardo Zorita, Gudrun Brattström, and David Frank 2016 Nature 532 7597 94-98 10.1038/nature17418 http://www.nature.com/nature/journal/v532/n7597/full/nature17418.html

Accurate modelling and prediction of the local to continental-scale hydroclimate response to global warming is essential given the strong impact of hydroclimate on ecosystem functioning, crop yields, water resources, and economic security. However, uncertainty in hydroclimate projections remains large, in part due to the short length of instrumental measurements available with which to assess climate models. Here we present a spatial reconstruction of hydroclimate variability over the past twelve centuries across the Northern Hemisphere derived from a network of 196 at least millennium-long proxy records. We use this reconstruction to place recent hydrological changes and future precipitation scenarios in a long-term context of spatially resolved and temporally persistent hydroclimate patterns. We find a larger percentage of land area with relatively wetter conditions in the ninth to eleventh and the twentieth centuries, whereas drier conditions are more widespread between the twelfth and nineteenth centuries. Our reconstruction reveals that prominent seesaw patterns of alternating moisture regimes observed in instrumental data across the Mediterranean, western USA, and China have operated consistently over the past twelve centuries. Using an updated compilation of 128 temperature proxy records, we assess the relationship between the reconstructed centennial-scale Northern Hemisphere hydroclimate and temperature variability. Even though dry and wet conditions occurred over extensive areas under both warm and cold climate regimes, a statistically significant co-variability of hydroclimate and temperature is evident for particular regions. We compare the reconstructed hydroclimate anomalies with coupled atmosphere-ocean general circulation model simulations and find reasonable agreement during pre-industrial times. However, the intensification of the twentieth-century-mean hydroclimate anomalies in the simulations, as compared to previous centuries, is not supported by our new multi-proxy reconstruction. This finding suggests that much work remains before we can model hydroclimate variability accurately, and highlights the importance of using palaeoclimate data to place recent and predicted hydroclimate changes in a millennium-long context. STUDY NOTES: Comparison of gridded proxy reconstructed and climate model simulated hydroclimate and temperature variability across the Northern Hemisphere over the past twelve centuries.

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/hydroclimate/ljungqvist2016/ Data Folder; Ljungqvist et al. 2016 Northern Hemisphere Hydroclimatic Reconstructions GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/hydroclimate/ljungqvist2016/readme-ljungqvist2016.txt Data Description; Readme File - Ljungqvist et al. 2016 Northern Hemisphere Hydroclimatic Reconstructions USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11