{"NOAAStudyId":"9924","contactInfo":{"address":"325 Broadway, E/NE31","city":"Boulder","constraints":"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.","country":"USA","dataCenterUrl":"https://www.ncdc.noaa.gov/data-access/paleoclimatology-data","email":"paleo@noaa.gov","fax":"303-497-6513","longName":"National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce ","phone":"303-497-6280","postalCode":"80305-3328","shortName":"DOC/NOAA/NESDIS/NCEI","state":"CO","type":"CONTACT INFORMATION"},"contributionDate":"2010-08-31","dataPublisher":"NOAA","dataType":"CLIMATE RECONSTRUCTIONS","dataTypeInformation":"https://www.ncdc.noaa.gov/data-access/paleoclimatology-data/datasets/climate-reconstruction","difMetadataLink":"http://www1.ncdc.noaa.gov/pub/data/metadata/published/paleo/dif/xml/noaa-recon-9924.xml","doi":null,"earliestYearBP":1950,"earliestYearCE":0,"entryId":"noaa-recon-9924","funding":[],"investigators":"Ljungqvist, F.C.","mostRecentYearBP":-49,"mostRecentYearCE":1999,"onlineResourceLink":"https://www.ncdc.noaa.gov/paleo/study/9924","originalSource":null,"publication":[{"abstract":"A new temperature reconstruction with decadal resolution, covering \nthe last two millennia, is presented for the extratropical Northern \nHemisphere (90-30°N), utilizing many palaeotemperature proxy records \nnever previously included in any large-scale temperature reconstruction. \nThe amplitude of the reconstructed temperature variability on centennial \ntime-scales exceeds 0.6°C. This reconstruction is the first to show \na distinct Roman Warm Period c. AD 1-300, reaching up to the 1961-1990 \nmean temperature level, followed by the Dark Age Cold Period c. AD 300-\n800. The Medieval Warm Period is seen c. AD 800–1300 and the Little Ice \nAge is clearly visible c. AD 1300-1900, followed by a rapid temperature \nincrease in the twentieth century. The highest average temperatures \nin the reconstruction are encountered in the mid to late tenth century \nand the lowest in the late seventeenth century. Decadal mean temperatures \nseem to have reached or exceeded the 1961-1990 mean temperature level \nduring substantial parts of the Roman Warm Period and the Medieval Warm \nPeriod. The temperature of the last two decades, however, is possibly \nhigher than during any previous time in the past two millennia, although\nthis is only seen in the instrumental temperature data and not in the \nmulti-proxy reconstruction itself. Our temperature reconstruction agrees \nwell with the reconstructions by Moberg et al. (2005) and Mann et al. \n(2008) with regard to the amplitude of the variability as well as the \ntiming of warm and cold periods, except for the period c. AD 300-800, \ndespite significant differences in both data coverage and methodology. \n\n\n","author":null,"citation":"Ljungqvist, F.C. 2010. \nA new reconstruction of temperature variability in the extra-tropical \nNorthern Hemisphere during the last two millennia.\nGeografiska Annaler: Physical Geography, Vol. 92 A(3), pp. 339-351,\nSeptember 2010.  DOI: 10.1111/j.1468-0459.2010.00399.x \n\n","edition":null,"identifier":{"id":"10.1111/j.1468-0459.2010.00399.x ","type":"doi","url":"http://dx.doi.org/10.1111/j.1468-0459.2010.00399.x "},"issue":null,"journal":"Geografiska Annaler: Physical Geography","pages":null,"pubRank":"1","pubYear":2010,"reportNumber":null,"title":"A new reconstruction of temperature variability in the extra-tropical  Northern Hemisphere during the last two millennia","type":"publication","volume":null}],"reconstruction":"Y","scienceKeywords":["Air Temperature Reconstruction","decadal resolution"],"site":[{"NOAASiteId":"34252","geo":{"geoType":"Feature","geometry":{"coordinates":["0","90","-180","180"],"type":"POLYGON"},"properties":{"easternmostLongitude":"180","maxElevationMeters":null,"minElevationMeters":null,"northernmostLatitude":"90","southernmostLatitude":"0","westernmostLongitude":"-180"}},"locationName":"Geographic Region>Northern Hemisphere","mappable":"N","paleoData":[{"NOAADataTableId":"38719","coreLengthMeters":null,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>reconstructions>air temperature"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/ljungqvist2010/ljungqvist2010.txt","linkText":"ljungqvist2010.txt","urlDescription":"Original Data and Full Metadata","variables":[]},{"NOAAKeywords":["earth science>paleoclimate>reconstructions>air temperature"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/ljungqvist2010/ljungqvist2010.xls","linkText":"ljungqvist2010.xls","urlDescription":"Original Data and Full Metadata","variables":[]}],"dataTableName":"Ljungqvist2010","dataTableNotes":null,"earliestYear":0,"earliestYearBP":1950,"earliestYearCE":0,"mostRecentYear":1999,"mostRecentYearBP":-49,"mostRecentYearCE":1999,"species":[],"timeUnit":"AD"}],"siteName":"Northern Hemisphere"}],"studyCode":null,"studyName":"Northern Hemisphere Extra-Tropics 2,000yr Decadal Temperature Reconstruction","studyNotes":"Multi-proxy temperature reconstruction for the extra-tropical Northern \nHemisphere (90-30°N) during the last two millennia based on 30 \npalaeotemperature proxy records with annual to multi-decadal resolution. \nProxy types include historical documentary records, seafloor sediment records, \nlake sediment records, speleothem records, ice-core records, varved thickness \nsediment records, tree-ring width and maximum latewood density records. \nThe reconstruction is presented as decadal anomalies in degrees C relative \nto the 1961–1990 reference period and provided with quantitative error bars. \n","version":"1.0","xmlId":"8818"}