noaa-lake-25311 Secret Lake, NW Greenland Holocene Chironomid d18O and Inferred Temperature Lasher, G.E.; Axford, Y.; McFarlin, J.M.; Kelly, M.A.; Osterberg, E.; Berkelhammer, M.B. Secret Lake, NW Greenland Holocene Chironomid d18O and Inferred Temperature 2018-10-01 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/25311 Investigator G.E. Lasher Investigator Y. Axford Investigator J.M. McFarlin Investigator M.A. Kelly Investigator E. Osterberg Investigator M.B. Berkelhammer earth science paleoclimate paleolimnology delta 18O,midge,null,per mil VSMOW,null,paleolimnology,null,isotope ratio mass spectrometry,N,null earth science paleoclimate paleolimnology delta 18O,lake water,null,per mil VSMOW,null,paleolimnology,averaged,null,N,3 point moving average of sample_inferred_lw_d18O values earth science paleoclimate paleolimnology delta 18O,lake water,null,per mil VSMOW,null,paleolimnology,differenced,null,N,sample_d18O_chiron - 22.4 per mil (methods outlined in Lasher et al. 2017 earth science paleoclimate climate reconstructions|paleolimnology maximum temperature,delta 18O,null,degree Celsius,annual,climate reconstructions|paleolimnology,anomalized,regression analysis,N,Thule annual temp-d18O: reconstruction_d18O relative to depth 0 (age -64 cal yr BP) / 0.44 earth science paleoclimate climate reconstructions|paleolimnology age,null,null,calendar year before present,null,climate reconstructions|paleolimnology,null,null,N,null earth science paleoclimate paleolimnology age,null,null,calendar year before present,null,paleolimnology,null,null,N,3 point moving average of sample_age values earth science paleoclimate paleolimnology delta 18O,midge,null,per mil VSMOW,null,paleolimnology,averaged,null,N,3 point moving average of sample_d18O_chiron values earth science paleoclimate climate reconstructions|paleolimnology depth,null,null,centimeter,null,climate reconstructions|paleolimnology,null,null,N,null earth science paleoclimate climate reconstructions|paleolimnology temperature,delta 18O,null,degree Celsius,annual,climate reconstructions|paleolimnology,anomalized,regression analysis,N,Global temp-d18O: reconstruction_d18O relative to depth 0 (age -64 cal yr BP) / 0.67 earth science paleoclimate climate reconstructions|paleolimnology temperature,delta 18O,null,degree Celsius,Jun-Aug,climate reconstructions|paleolimnology,anomalized,regression analysis,N,Thule summer temp-d18O: reconstruction_d18O relative to depth 0 (age -64 cal yr BP) / 0.59 earth science paleoclimate paleolimnology reconstruction earth science paleoclimate paleolimnology oxygen isotopes geoscientificInformation 7730 cal yr BP -64 cal yr BP Complete 76.58021 76.58021 -68.65907 -68.65907 250 250 Continent North America Greenland Secret Lake>LATITUDE 76.58021>LONGITUDE -68.65907 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 G. Everett Lasher, Yarrow Axford, Jamie M. McFarlin, Meredith A. Kelly, Erich C.Osterberg, Max B. Berkelhammer 2017 Quaternary Science Reviews 170 44-55 10.1016/j.quascirev.2017.06.016 ttps://www.sciencedirect.com/science/article/pii/S0277379116305650

Reconstructions of Holocene lake water isotopic composition based upon subfossil aquatic organic material offer new insights into Arctic climate. We present quantitative estimates of warmth during the Holocene Thermal Maximum in northwest Greenland, inferred from oxygen isotopes of chironomid head capsules and aquatic moss preserved in lake sediments. d18O values of chironomids from surface sediments of multiple Greenland lakes indicate that these subfossil remains record the d18O values of the lake water in which they grow. Our lake water d18O reconstruction is supported by downcore agreement with d18O values in aquatic moss and chironomid remains. d18O of both organic materials from Secret Lake decrease after 4 ka (ka = thousands of years ago) by 3 permil into the Neoglacial. We argue that lake water at Secret Lake primarily reflects precipitation d18O values, which is strongly correlated with air temperature in NW Greenland, and that this signal is biased towards summer and early autumn conditions. Other factors may have influenced Secret Lake d18O values through the Holocene, including evaporation of lake water and changing seasonality and source of precipitation. The maximum early Holocene summer and early autumn-biased temperature anomaly at Secret Lake is 2.5-4C warmer than present from 7.7 (the beginning of our record) to ~6 ka. The maximum late Holocene cold anomaly (which includes the Little Ice Age) is 1.5-3C colder than present. These ranges of possible temperature anomalies reflect uncertainty in the d18O - temperature relationship for precipitation at the study site through the Holocene. STUDY NOTES: Oxygen isotope record measured on chironomid head capsule macrofossils, with inferred temperatures

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/greenland/secret2017.txt NOAA Template File; Secret Lake Chironomid d18O and Inferred Temperature USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11