{"NOAAStudyId":"13077","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":"2012-06-30","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-13077.xml","doi":null,"earliestYearBP":728,"earliestYearCE":1222,"entryId":"noaa-lake-13077","funding":[],"investigators":"Gonyo, A.W.; Yu, Z.; Bebout, G.E.","mostRecentYearBP":-57,"mostRecentYearCE":2007,"onlineResourceLink":"https://www.ncdc.noaa.gov/paleo/study/13077","originalSource":null,"publication":[{"abstract":"Climate records during the last millennium are essential in placing \r\nrecent anthropogenic-induced climate change into the context of \r\nnatural climatic variability. However, detailed records are still \r\nsparse in Alaska, and these records would help elucidate climate \r\npatterns and possible forcing mechanisms. Here we present a \r\nmultiple-proxy sedimentary record from Kepler Lake in south-central \r\nAlaska to reconstruct climatic and environmental changes over the \r\nlast 800 years. Two short cores (85 and 101 cm long) from this \r\ngroundwater-fed marl lake provide a detailed stable isotope \r\nand sediment lithological record with chronology based on four \r\nAMS 14C dates on terrestrial macrofossils and 210Pb analysis. \r\nThe d18O values of inorganic calcite (CaCO3) range from -17.0 \r\nto -15.7 ‰, with the highest values during the period of 1450-1850 AD, \r\ncoeval with the well-documented Little Ice Age (LIA) cold interval \r\nin Alaska. The high d18O values during the cold LIA are interpreted \r\nas reflecting shifts in atmospheric circulation. A weakening of \r\nthe wintertime Aleutian low pressure system residing over the Gulf \r\nof Alaska during the LIA would have resulted in 18O-enriched winter \r\nprecipitation as well as a colder and possibly drier winter climate \r\nin south-central Alaska. Also, elevated calcite contents of >80 % \r\nduring the LIA reflect a lowering of lake level and/or enhanced \r\nseasonality (warmer summer and colder winter), as calcite \r\nprecipitation in freshwater lakes is primarily a function of peak \r\nsummer temperature and water depth. This interpretation is also \r\nsupported by high d13C values, likely reflecting high aquatic \r\nproductivity or increased residence times of the lake water \r\nduring lower lake levels. The lower lake levels and warmer \r\nsummers would have increased evaporative enrichment in 18O, \r\nalso contributing to the high d18O values during the LIA. \r\nOur results indicate that changes in atmospheric circulation \r\nwere an important component of climate change during the last \r\nmillennium, exerting strong influence on regional climate \r\nin Alaska and the Arctic. \r\n","author":null,"citation":"Gonyo, A.W., Z. Yu, and G.E. Bebout. 2012. \r\nLate Holocene change in climate and atmospheric circulation inferred \r\nfrom geochemical records at Kepler Lake, south-central Alaska. \r\nJournal of Paleolimnology, Vol. 48, No. 1, June 2012, pp. 55-67. \r\nDOI: 10.1007/s10933-012-9603-8","edition":null,"identifier":{"id":"10.1007/s10933-012-9603-8","type":"doi","url":"http://dx.doi.org/10.1007/s10933-012-9603-8"},"issue":null,"journal":"Journal of Paleolimnology","pages":null,"pubRank":"1","pubYear":2012,"reportNumber":null,"title":"Late Holocene change in climate and atmospheric circulation inferred  from geochemical records at Kepler Lake, south-central Alaska","type":"publication","volume":null}],"reconstruction":"N","scienceKeywords":["PAGES Arctic 2k","Arctic","Little Ice Age (LIA)"],"site":[{"NOAASiteId":"53155","geo":{"geoType":"Feature","geometry":{"coordinates":["61.5544","-149.2119"],"type":"POINT"},"properties":{"easternmostLongitude":"-149.2119","maxElevationMeters":"22","minElevationMeters":"22","northernmostLatitude":"61.5544","southernmostLatitude":"61.5544","westernmostLongitude":"-149.2119"}},"locationName":"Continent>North America>United States Of America>Alaska","mappable":"Y","paleoData":[{"NOAADataTableId":"22531","coreLengthMeters":null,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>paleolimnology>geochemistry","earth science>paleoclimate>paleolimnology>oxygen isotopes","earth science>paleoclimate>paleolimnology>physical properties","earth science>paleoclimate>paleolimnology>carbon isotopes"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/alaska/kepler2012.txt","linkText":"kepler2012.txt","urlDescription":"Data","variables":[{"cvAdditionalInfo":null,"cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"centimeter","cvWhat":"depth variable>depth>depth at sample end"},{"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":null,"cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>bulk geological material>sediment","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"gram per cubic centimeter","cvWhat":"physical property>density"},{"cvAdditionalInfo":null,"cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>bulk geological material>sediment","cvMethod":"loss on ignition","cvSeasonality":null,"cvShortName":null,"cvUnit":"weight percent","cvWhat":"biological material>bulk biological material>organic matter"},{"cvAdditionalInfo":null,"cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>bulk geological material>sediment","cvMethod":"loss on ignition","cvSeasonality":null,"cvShortName":null,"cvUnit":"weight percent","cvWhat":"geological material>identified mineral>carbonate>calcium carbonate"},{"cvAdditionalInfo":null,"cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>bulk geological material>sediment","cvMethod":"loss on ignition","cvSeasonality":null,"cvShortName":null,"cvUnit":"weight percent","cvWhat":"geological material>bulk geological material>mineral matter"},{"cvAdditionalInfo":"calcite","cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>identified mineral>carbonate","cvMethod":"isotope ratio mass spectrometry","cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil VPDB","cvWhat":"chemical composition>isotope>isotope ratio>delta 13C"},{"cvAdditionalInfo":"calcite","cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>identified mineral>carbonate","cvMethod":"isotope ratio mass spectrometry","cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil VPDB","cvWhat":"chemical composition>isotope>isotope ratio>delta 18O"},{"cvAdditionalInfo":null,"cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"biological material>bulk biological material>organic matter","cvMethod":"isotope ratio mass spectrometry","cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil VPDB","cvWhat":"chemical composition>isotope>isotope ratio>delta 13C"},{"cvAdditionalInfo":null,"cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>bulk geological material>sediment","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"dimensionless","cvWhat":"chemical composition>element or compound ratio>carbon/nitrogen"},{"cvAdditionalInfo":null,"cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"biological material>bulk biological material>organic matter","cvMethod":"isotope ratio mass spectrometry","cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil AIR","cvWhat":"chemical composition>isotope>isotope ratio>delta 15N"}]},{"NOAAKeywords":["earth science>paleoclimate>paleolimnology>oxygen isotopes","earth science>paleoclimate>paleolimnology>geochemistry","earth science>paleoclimate>paleolimnology>physical properties","earth science>paleoclimate>paleolimnology>carbon isotopes"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/alaska/kepler2012.xls","linkText":"kepler2012.xls","urlDescription":"Data","variables":[]}],"dataTableName":"KeplerC2","dataTableNotes":null,"earliestYear":1222,"earliestYearBP":728,"earliestYearCE":1222,"mostRecentYear":2007,"mostRecentYearBP":-57,"mostRecentYearCE":2007,"species":[],"timeUnit":"AD"}],"siteName":"Kepler Lake"}],"studyCode":null,"studyName":"Kepler Lake, Alaska 800 Year Multiproxy Sediment Data","studyNotes":"Multiproxy sediment data from Kepler Lake, south-central Alaska, \nfor the past 800 years. Kepler Lake is a groundwater-fed marl lake. \nPaleoenvironmental proxies measured include stable isotopes, \nC/N ratios, Loss-on-ignition, and bulk sediment density. \n\nKepler Lake, Alaska: 61°33'16\"N, 149°12'43\"W, 22m elevation.","version":"1.0","xmlId":"11119"}