noaa-lake-17350 Baffin Island Lakes Surface Sediment Branched GDGT Data Shanahan, T.M.; Hughen, K.A.; Van Mooy, B. Baffin Island Lakes Surface Sediment Branched GDGT Data 2014-10-19 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/17350 Investigator Shanahan, T.M. Investigator K.A. Hughen Investigator B. Van Mooy earth science paleoclimate paleolimnology sample identification,null,null,null,null,paleolimnology,null,null,N,null earth science paleoclimate paleolimnology isoprenoid glycerol dialkyl glycerol tetraether,sediment,null,percent,null,paleolimnology,null,null,N,crenarchaeol prime earth science paleoclimate paleolimnology branched and isoprenoid tetraether index,sediment,null,dimensionless,null,paleolimnology,null,null,N,null earth science paleoclimate paleolimnology branched glycerol dialkyl glycerol tetraether,sediment,null,percent,null,paleolimnology,null,null,N,Branched GDGT-Ib earth science paleoclimate paleolimnology branched glycerol dialkyl glycerol tetraether,sediment,null,percent,null,paleolimnology,null,null,N,Branched GDGT-IIc earth science paleoclimate paleolimnology branched glycerol dialkyl glycerol tetraether,sediment,null,percent,null,paleolimnology,null,null,N,Branched GDGT-III earth science paleoclimate paleolimnology cyclization index of branched tetraethers,sediment,null,dimensionless,null,paleolimnology,null,null,N,null earth science paleoclimate paleolimnology methylation index of branched tetraethers,sediment,null,dimensionless,null,paleolimnology,null,null,N,null earth science paleoclimate paleolimnology tetraether index of 86 carbon atoms,sediment,null,dimensionless,null,paleolimnology,null,null,N,null earth science paleoclimate paleolimnology branched glycerol dialkyl glycerol tetraether,sediment,null,percent,null,paleolimnology,null,null,N,Branched GDGT-I earth science paleoclimate paleolimnology branched glycerol dialkyl glycerol tetraether,sediment,null,percent,null,paleolimnology,null,null,N,Branched GDGT-IIb earth science paleoclimate paleolimnology isoprenoid glycerol dialkyl glycerol tetraether,sediment,null,percent,null,paleolimnology,null,null,N,crenarchaeol earth science paleoclimate paleolimnology isoprenoid glycerol dialkyl glycerol tetraether,sediment,null,percent,null,paleolimnology,null,null,N,Isoprenoid GDGT-0 earth science paleoclimate paleolimnology isoprenoid glycerol dialkyl glycerol tetraether,sediment,null,percent,null,paleolimnology,null,null,N,Isoprenoid GDGT-1 earth science paleoclimate paleolimnology isoprenoid glycerol dialkyl glycerol tetraether,sediment,null,percent,null,paleolimnology,null,null,N,Isoprenoid GDGT-3 earth science paleoclimate paleolimnology branched glycerol dialkyl glycerol tetraether,sediment,null,percent,null,paleolimnology,null,null,N,Branched GDGT-Ic earth science paleoclimate paleolimnology branched glycerol dialkyl glycerol tetraether,sediment,null,percent,null,paleolimnology,null,null,N,Branched GDGT-IIIb earth science paleoclimate paleolimnology branched glycerol dialkyl glycerol tetraether,sediment,null,percent,null,paleolimnology,null,null,N,Branched GDGT-IIIc earth science paleoclimate paleolimnology isoprenoid glycerol dialkyl glycerol tetraether,sediment,null,percent,null,paleolimnology,null,null,N,Isoprenoid GDGT-2 earth science paleoclimate paleolimnology branched glycerol dialkyl glycerol tetraether,sediment,null,percent,null,paleolimnology,null,null,N,Branched GDGT-II earth science paleoclimate paleolimnology geochemistry geoscientificInformation -50 cal yr BP -50 cal yr BP Complete 62.112 73.042 -87.18 -62.17 Continent North America Canada Nunavut Baffin Island Lakes>LATITUDE >LONGITUDE 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 Timothy M. Shanahan, Konrad A. Hughen, Benjamin A.S. Van Mooy 2013 Organic Geochemistry 64 119-128 10.1016/j.orggeochem.2013.09.010 http://www.sciencedirect.com/science/article/pii/S0146638013002015

Understanding the causes and potential ecological and environmental impacts of recent and future temperature changes in the Arctic requires a better understanding of long term climate variability. Amongst the most promising new geochemical tools for sedimentary paleotemperature reconstructions are those based on the glycerol diakyl glycerol tetraethers (GDGTs). Although a number of studies have recently developed empirical calibrations for the temperature sensitivity of isoprenoid GDGTs (i.e., the TEX86 index) and the branched GDGTs (i.e., the MBT/CBT index) in mid and low latitude lakes, there is very little data from lakes in the Arctic. Here, we examine the temperature and environmental controls on GDGT abundances in a transect of small lakes (n = 59) distributed across Baffin Island in the eastern Canadian Arctic. Isoprenoid and branched GDGTs are ubiquitous in these lakes. The temperature control on the isoprenoid GDGT distributions is weak, although there is a significant relationship between the branched GDGT distributions and warm season temperature. Furthermore, published relationships developed between branched GDGTs and mean annual air temperatures in tropical lakes yield reconstructed temperatures from Arctic lakes that are consistent with Arctic summer air temperature. This suggests that empirical calibrations from branched GDGTs in lakes reflect the seasonality of branched GDGT production. For example, at low latitudes there is little seasonality in temperature, and branched GDGT production records air temperatures throughout the year. In the Arctic however, branched GDGTs are likely produced in summer, when the temperatures are warmest, sunlight hours are greatest and ice cover is diminished. Due to the extreme seasonality and short window of Arctic productivity, the use of branched GDGTs for summer paleotemperature reconstructions likely remains robust back through time. However, interpretations of paleotemperatures from branched GDGTs in temperate lakes may require careful consideration about potential changes in the seasonal timing of branched GDGT production. STUDY NOTES: Calibration of the branched GDGT/temperature relationship for lake surface sediments collected on Baffin Island, Arctic Canada. Data include water temperature and water chemistry measurements for 60 Baffin Island lakes, plus fractional abundances of iso- and br-GDGTs and calculated parameters (TEX86, BIT, MBT, CBT) for lake surface sediments.

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/canada/baffin/baffin2013gdgt.txt Data File; Surface Sediment Branched GDGT Data USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11