noaa-recon-23710 Western North America Network of Moisture Sensitive Proxy Records from 6000 yr BP Hermann, N.W.; Oster, J.L.; Ibarra, D.E. Western North America Network of Moisture Sensitive Proxy Records from 6000 yr BP 2018-03-21 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/23710 Investigator N.W. Hermann Investigator J.L. Oster Investigator D.E. Ibarra earth science paleoclimate climate reconstructions sample identification,null,null,null,null,climate reconstructions,null,null,C,number of aggregated site or name of sites aggregated earth science paleoclimate climate reconstructions moisture index,multiple proxies,null,null,null,climate reconstructions,null,null,C,hydroclimatic designation at 6 ka earth science paleoclimate climate reconstructions number of samples,null,null,count,null,climate reconstructions,null,null,N,number of sites for aggregated locations earth science paleoclimate climate reconstructions notes,null,null,null,null,climate reconstructions,null,null,C,Reference for sample earth science paleoclimate climate reconstructions longitude,null,null,degree east,null,climate reconstructions,null,null,N,null earth science paleoclimate climate reconstructions notes,null,null,null,null,climate reconstructions,null,null,C,Aggregate Confidence between site designations noted by Robust Majority earth science paleoclimate climate reconstructions latitude,null,null,degree north,null,climate reconstructions,null,null,N,null earth science paleoclimate climate reconstructions sample identification,null,null,null,null,climate reconstructions,null,null,C,Name of site or number for aggregated sites earth science paleoclimate climate reconstructions notes,null,null,null,null,climate reconstructions,null,null,C,Type of paleoclimate archive earth science paleoclimate climate reconstructions moisture index,multiple proxies,null,null,null,climate reconstructions,null,null,C,hydroclimatic designation at 6 ka (d=drier earth science paleoclimate reconstructions precipitation geoscientificInformation Precipitation Reconstruction 6000 cal yr BP 6000 cal yr BP Complete 28 50 -125 -105 Continent North America Central Western North America>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 Hermann, N.W., J.L. Oster, and D.E. Ibarra 2018 Journal of Quaternary Science 10.1002/jqs.3023

Mid-Holocene paleoclimate proxy records from drought-sensitive western North America suggest widespread aridity in areas dominated by winter precipitation. We present spatial comparisons of a diverse network of moisture-sensitive proxies with 12 global circulation model simulations from the Paleoclimate Model Intercomparison Project to determine the most important atmospheric drivers behind observed mid-Holocene aridity in this region. Although model-proxy agreement is low for most models, in part reflecting small mid-Holocene precipitation anomalies, three show relatively strong agreement by successfully simulating arid conditions across the Pacific Northwest. The model that shows the strongest spatial agreement with the proxy network reveals an anticyclonic wind anomaly that is similar to but weaker than anomalies noted during westwide drought episodes of the past 500 years. This model suggests increased transient upper level ridging that reduced winter water vapor transport from the south-west during the mid-Holocene. These mechanisms are similar to those suggested to have supported megadrought conditions in western North America during the Medieval Climate Anomaly and which are also simulated in anthropogenic warming scenarios. Future work on quantitative proxy records to enhance temporal and spatial coverage, and explicitly address issues of seasonality, will improve the quality of future climate model–data comparison studies. STUDY NOTES: Provided Keywords: mid-Holocene, proxy-model comparison, terrestrial hydroclimate

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/hydroclimate/hermann2018/hermann2018-aggregatesite.txt NOAA Template File; Aggregate Site Hydroclimatic designation data at 6ka GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/hydroclimate/hermann2018/hermann2018-RecordsUsed_Metadata.txt NOAA Synthesis Template File; Metadata for Records Used in Study GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/hydroclimate/hermann2018/hermann2018-finalnetwork.txt NOAA Template File; Final Network Hydroclimatic designations USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11