{"NOAAStudyId":"19768","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":"2016-02-08","dataPublisher":"NOAA","dataType":"PALEOLIMNOLOGY","dataTypeInformation":"https://www.ncdc.noaa.gov/data-access/paleoclimatology-data/datasets/lake","difMetadataLink":"http://www1.ncdc.noaa.gov/pub/data/metadata/published/paleo/dif/xml/noaa-lake-19768.xml","doi":null,"earliestYearBP":1949,"earliestYearCE":1,"entryId":"noaa-lake-19768","funding":[{"fundingAgency":"Natural Environment Research Council radiocarbon allocation","fundingGrant":"1108.0305"}],"investigators":"Metcalfe, S.; Jones, M.D.; Davies, S.J.; Noren, A.; MacKenzie, A.","mostRecentYearBP":-51,"mostRecentYearCE":2001,"onlineResourceLink":"https://www.ncdc.noaa.gov/paleo/study/19768","originalSource":null,"publication":[{"abstract":"High-resolution titanium (Ti) data obtained using an ITRAX XRF core scanner from a laminated sediment core from the Laguna de Juanacatlan, western central Mexico yield a unique high-resolution record of runoff (precipitation) change for the last 2000 years. In the absence of reliable, long-term meteorological records, comparison of the Ti data with information from the rich Spanish colonial period archives and the post-Independence period, confirms that Ti is a proxy for runoff. This interpretation is supported by comparison with other high-resolution archives from the surrounding region, primarily tree rings and other lake sediment sequences. The Juanacatlan Ti record is therefore a proxy for summer, monsoonal rainfall. The record provides new evidence from the Pacific margin of tropical North America of the occurrence of dry conditions through much of the Classic period (c. ad 300-900), and wetter conditions during the later Medieval period (c. ad 1200-1350). The period commonly known as the 'Little Ice Age' (LIA) shows considerable variability, with dry conditions in the early part (c. ad 1400-1600) and wetter conditions, punctuated by multiyear droughts through the eighteenth century. A notable feature of the record is the apparent decoupling of lacustrine sedimentation from the climate since the mid-twentieth century, possibly resulting from anthropogenic disturbance. Preliminary interpretations of the Ti record indicate that patterns are consistent with changes in monsoon strength associated with ENSO and solar forcing over the last two millennia. ","author":{"name":"Metcalfe, S.E.; Jones, M.D.; Davies, S.J.; Noren, A.; MacKenzie, A."},"citation":"Metcalfe, S.E.; Jones, M.D.; Davies, S.J.; Noren, A.; MacKenzie, A. 2010. Climate variability over the last two millennia in the North American Monsoon region, recorded in laminated lake sediments from Laguna de Juanacatlan, Mexico. The Holocene, 20(8), 1195-1206. doi: 10.1177/0959683610371994","edition":null,"identifier":{"id":"10.1177/0959683610371994","type":"doi","url":"http://dx.doi.org/10.1177/0959683610371994"},"issue":"8","journal":"The Holocene","pages":"1195-1206","pubRank":"1","pubYear":2010,"reportNumber":null,"title":"Climate variability over the last two millennia in the North American Monsoon region, recorded in laminated lake sediments from Laguna de Juanacatlan, Mexico","type":"publication","volume":"20"}],"reconstruction":"N","scienceKeywords":null,"site":[{"NOAASiteId":"56722","geo":{"geoType":"Feature","geometry":{"coordinates":["20.6293","-104.7364"],"type":"POINT"},"properties":{"easternmostLongitude":"-104.7364","maxElevationMeters":"2000","minElevationMeters":"2000","northernmostLatitude":"20.6293","southernmostLatitude":"20.6293","westernmostLongitude":"-104.7364"}},"locationName":"Continent>North America>Mexico","mappable":"Y","paleoData":[{"NOAADataTableId":"30412","coreLengthMeters":null,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>paleolimnology>geochemistry"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/mexico/juanacatlan2010ti.txt","linkText":"Laguna de Juanacatlan Titanium Data","urlDescription":"Data File","variables":[{"cvAdditionalInfo":null,"cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"calendar year before present","cvWhat":"age variable>age"},{"cvAdditionalInfo":null,"cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"year Common Era","cvWhat":"age variable>age"},{"cvAdditionalInfo":"not normalised - annual values averaged from original 200 um resolution data set","cvDataType":"PALEOLIMNOLOGY","cvDetail":"averaged","cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>bulk geological material>sediment","cvMethod":"energy-dispersive x-ray fluorescence spectroscopy","cvSeasonality":null,"cvShortName":null,"cvUnit":"peak area integral","cvWhat":"chemical composition>element or single-element molecule>titanium"}]}],"dataTableName":"Juanacatlan2010Ti","dataTableNotes":null,"earliestYear":1949,"earliestYearBP":1949,"earliestYearCE":1,"mostRecentYear":-51,"mostRecentYearBP":-51,"mostRecentYearCE":2001,"species":[],"timeUnit":"cal yr BP"}],"siteName":"Laguna de Juanacatlan"}],"studyCode":null,"studyName":"Laguna de Juanacatlan, Mexico 2000 Year Titanium Data","studyNotes":"High-resolution titanium (Ti) data from Laguna de Juanacatlan, central Mexico, for the past 2,000 years.","version":"1.0","xmlId":"17551"}