noaa-lake-6201 Lake V57, Nunavut 2,000 Year Midge Inferred Temperatures Porinchu, D.F.; MacDonald, G.M.; Rolland, N. Lake V57, Nunavut 2,000 Year Midge Inferred Temperatures 2008-11-01 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/6201 Investigator D.F. Porinchu Investigator G.M. MacDonald Investigator N. Rolland earth science paleoclimate climate reconstructions|insect|paleolimnology surface air temperature,midge assemblage,null,degree Celsius,Jul,climate reconstructions|insect|paleolimnology,null,regression analysis,N,calibration data set: Central Canadian Arctic Porinchu et al. 2009; weighted-averaging partial least-squares regression earth science paleoclimate climate reconstructions|insect|paleolimnology lake surface temperature,midge assemblage,null,degree Celsius,summer,climate reconstructions|insect|paleolimnology,null,regression analysis,N,weighted-averaging partial least-squares regression earth science paleoclimate climate reconstructions|insect|paleolimnology depth,null,null,centimeter,null,climate reconstructions|insect|paleolimnology,null,null,N,null earth science paleoclimate insect|paleolimnology detrended correspondence analysis axis,null,null,dimensionless,null,insect|paleolimnology,null,null,N,DCA axis 1 of chironomid assemblage earth science paleoclimate climate reconstructions|insect|paleolimnology age,null,null,year Common Era,null,climate reconstructions|insect|paleolimnology,null,null,N,null earth science paleoclimate paleolimnology organic matter,sediment,null,weight percent,null,paleolimnology,null,loss on ignition,N,loss on ignition 550 degrees C for two hours earth science paleoclimate paleolimnology reconstruction geoscientificInformation Air Temperature Reconstruction PAGES 2k Network PAGES Arctic 2k 1918 cal yr BP -49 cal yr BP Complete 68.657 68.657 -105.357 -105.357 Continent North America Canada Nunavut Lake V57>LATITUDE 68.657>LONGITUDE -105.357 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 Porinchu, D.F., G.M. MacDonald, and N. Rolland 2009 Journal of Paleolimnology 41 1 177-188 10.1007/s10933-008-9263-x

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, Heterotrissocladius decreased in relative abundance and taxa such as Corynocera ambigua, C. oliveri, Psectrocladius sordidellus type, and Pentanneurini increased in relative abundance. Previously 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 to the south suggesting a regionally synchronous response to climate forcing. STUDY NOTES: Midge-inferred Average July Air Temperature (AJAT) and Summer Surface Water Temperature (SSWT) for the last 2,000 years for Lake V57, Nunavut, Canada

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/canada/nu/v57midge2008.txt GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/canada/nu/v57midge2008.xls USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11