{"NOAAStudyId":"6201","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":"2008-11-01","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-6201.xml","doi":null,"earliestYearBP":1918,"earliestYearCE":32,"entryId":"noaa-lake-6201","funding":[],"investigators":"Porinchu, D.F.; MacDonald, G.M.; Rolland, N.","mostRecentYearBP":-49,"mostRecentYearCE":1999,"onlineResourceLink":"https://www.ncdc.noaa.gov/paleo/study/6201","originalSource":null,"publication":[{"abstract":"A lake sediment core recovered from Lake V57 on Victoria Island, Nunavut, Canada, spanning the last 2000 years, was analyzed for sub-fossil midge remains and organic-matter content estimated by loss-on-ignition (LOI)). Significant changes in midge community composition occurred during the last 2000 years, with a distinct midge community appearing after 1600 AD. The chironomid community between 0 and 1600 AD was dominated by Heterotrissocladius, Tanytarsus, Abiskomyia, and Paracladius. At approximately 1600 AD, \r\nHeterotrissocladius decreased in relative abundance and taxa such as Corynocera ambigua, C. oliveri, Psectrocladius sordidellus type, and Pentanneurini increased in relative abundance. \r\nPreviously published midge-based inference models for average July air temperature (AJAT) and summer surface-water temperature (SSWT) were applied to the subfossil midge stratigraphy.  The AJAT reconstruction indicates relatively cool conditions existed between 1100 and 1600 AD, with exceptional warming occurring after 1600 AD, as lake productivity inferred from organic-matter content increased concomitantly with midge-inferred AJAT and SSWT. The cooler conditions between 1200 and 1600 AD, and the pattern of warming over recent centuries inferred from Lake V57 is broadly consistent with temperature-sensitive biogenic silica records from other sites in the central Canadian Arctic and the treeline zone \r\nto the south suggesting a regionally synchronous response to climate forcing.\r\n","author":{"name":"Porinchu, D.F., G.M. MacDonald, and N. Rolland"},"citation":"Porinchu, D.F., G.M. MacDonald, and N. Rolland. 2009. A 2000 year midge-based paleotemperature reconstruction from the Canadian Arctic Archipelago. Journal of Paleolimnology, 41(1), 177-188. doi: 10.1007/s10933-008-9263-x","edition":null,"identifier":{"id":"10.1007/s10933-008-9263-x","type":"doi","url":"http://dx.doi.org/10.1007/s10933-008-9263-x"},"issue":"1","journal":"Journal of Paleolimnology","pages":"177-188","pubRank":"1","pubYear":2009,"reportNumber":null,"title":"A 2000 year midge-based paleotemperature reconstruction from the Canadian Arctic Archipelago","type":"publication","volume":"41"}],"reconstruction":"Y","scienceKeywords":["PAGES Arctic 2k","Air Temperature Reconstruction","PAGES 2k Network"],"site":[{"NOAASiteId":"20678","geo":{"geoType":"Feature","geometry":{"coordinates":["68.657","-105.357"],"type":"POINT"},"properties":{"easternmostLongitude":"-105.357","maxElevationMeters":null,"minElevationMeters":null,"northernmostLatitude":"68.657","southernmostLatitude":"68.657","westernmostLongitude":"-105.357"}},"locationName":"Continent>North America>Canada>Nunavut","mappable":"Y","paleoData":[{"NOAADataTableId":"9523","coreLengthMeters":null,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>paleolimnology>reconstruction"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/canada/nu/v57midge2008.txt","linkText":"v57midge2008.txt","urlDescription":"Data","variables":[{"cvAdditionalInfo":"calibration data set: Central Canadian Arctic Porinchu et al. 2009; weighted-averaging partial least-squares regression","cvDataType":"CLIMATE RECONSTRUCTIONS|INSECT|PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"reconstruction material>biological assemblage>midge assemblage","cvMethod":"regression analysis","cvSeasonality":"1-month period>Jul","cvShortName":null,"cvUnit":"degree Celsius","cvWhat":"earth system variable>temperature variable>temperature>air temperature>surface air temperature"},{"cvAdditionalInfo":"weighted-averaging partial least-squares regression","cvDataType":"CLIMATE RECONSTRUCTIONS|INSECT|PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"reconstruction material>biological assemblage>midge assemblage","cvMethod":"regression analysis","cvSeasonality":"non-calendric period>summer","cvShortName":null,"cvUnit":"degree Celsius","cvWhat":"earth system variable>temperature variable>temperature>lake water temperature>lake surface temperature"},{"cvAdditionalInfo":null,"cvDataType":"CLIMATE RECONSTRUCTIONS|INSECT|PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"centimeter","cvWhat":"depth variable>depth"},{"cvAdditionalInfo":null,"cvDataType":"CLIMATE RECONSTRUCTIONS|INSECT|PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"year Common Era","cvWhat":"age variable>age"},{"cvAdditionalInfo":"loss on ignition 550 degrees C for two hours","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":"DCA axis 1 of chironomid assemblage","cvDataType":"INSECT|PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"dimensionless","cvWhat":"statistical variable>multivariate eigenvector-based variable>correspondence analysis axis>detrended correspondence analysis axis"}]},{"NOAAKeywords":["earth science>paleoclimate>paleolimnology>reconstruction"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/canada/nu/v57midge2008.xls","linkText":"v57midge2008.xls","urlDescription":"Data","variables":[]}],"dataTableName":"Lake V57 Core V57","dataTableNotes":null,"earliestYear":1918,"earliestYearBP":1918,"earliestYearCE":32,"mostRecentYear":-49,"mostRecentYearBP":-49,"mostRecentYearCE":1999,"species":[],"timeUnit":"cal yr BP"}],"siteName":"Lake V57"}],"studyCode":null,"studyName":"Lake V57, Nunavut 2,000 Year Midge Inferred Temperatures","studyNotes":"Midge-inferred Average July Air Temperature (AJAT) and Summer Surface Water Temperature (SSWT) for the last 2,000 years for Lake V57, Nunavut, Canada","version":"1.0","xmlId":"2159"}