Lake Cadagno Switzerland 11000 Year MBT/CBT Temperature Reconstruction Niemann, H.; Stadnitskaia, A.; Wirth, S.B.; Gilli, A.; Anselmetti, F.S.; Sinninghe Damsté, J.S.; Schouten, S.; Hopmans, E.C.; Lehmann, M.F. Niemann, H. Stadnitskaia, A. Wirth, S.B. Gilli, A. Anselmetti, F.S. Sinninghe Damsté, J.S. Schouten, S. Hopmans, E.C. Lehmann, M.F. Air Temperature Reconstruction Little Ice Age (LIA) Medieval Warm Period earth science/paleoclimate/climate reconstructions|paleolimnology (age at sample start,null,null,calendar year before present,null,climate reconstructions|paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (branched and isoprenoid tetraether index,sediment,null,null,null,paleolimnology,null,null,N,null) earth science/paleoclimate/climate reconstructions|paleolimnology (surface air temperature,glycerol dialkyl glycerol tetraether index,null,degree Celsius,annual,climate reconstructions|paleolimnology,null,null,N,using MBT/CBT) earth science/paleoclimate/climate reconstructions|paleolimnology (depth,null,null,centimeter,null,climate reconstructions|paleolimnology,null,null,N,composite depth corrected for slump deposits) earth science/paleoclimate/paleolimnology (cyclization index of branched tetraethers,sediment,null,null,null,paleolimnology,null,null,N,null) earth science/paleoclimate/climate reconstructions|paleolimnology (pH,glycerol dialkyl glycerol tetraether index|soil,null,dimensionless,null,climate reconstructions|paleolimnology,null,null,N,using CBT) earth science/paleoclimate/paleolimnology (methylation index of branched tetraethers,sediment,null,null,null,paleolimnology,null,null,N,null) earth science/paleoclimate/climate reconstructions|paleolimnology (age at sample end,null,null,calendar year before present,null,climate reconstructions|paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology earth science/paleoclimate/paleolimnology (Lake Cadagno>LATITUDE 46.5507>LONGITUDE 8.7139) A novel proxy for continental mean annual air temperature (MAAT) and soil pH, the MBT/CBT paleothermometer, is based on the temperature (T) and pH-dependent distribution of specific bacterial membrane lipids (branched glycerol dialkyl glycerol tetraethers – GDGTs) in soil organic matter. Here, we tested the applicability of the MBT/CBT-paleothermometer to sediments from Lake Cadagno, a high Alpine lake in southern Switzerland with a small catchment of 2.4 km2. We analysed the distribution of bacterial GDGTs in catchment soils and in a radiocarbon dated sediment core from the centre of the lake, covering the past 11 000 yr. The distribution of bacterial GDGTs in the catchment soils is very similar to that in the lake's surface sediments, indicating a common origin of the lipids. Consequently, their transfer from the soils into the sediment record seems undisturbed, probably without any significant alteration of their distribution through in situ production in the lake itself or early diagenesis of branched GDGTs. The MBT/CBT-inferred MAAT estimates from soils and surface sediments are in good agreement with instrumental values for the Lake Cadagno region (~0.5°C). Moreover, downcore MBT/CBT-derived MAAT estimates match in timing and magnitude other proxy-based T reconstructions from nearby locations for the last two millennia. Major climate anomalies recorded by the MBT/CBT-paleothermometer are, for instance, the Little Ice Age (~14th to 19th century) and the Medieval Warm Period (MWP, ~9th to 14th century). Together, our observations indicate the quantitative applicability of the MBT/CBT-paleothermometer to Lake Cadagno sediments. In addition to the MWP, our lacustrine paleo T record indicates Holocene warm phases at about 3, 5, 7 and 11 kyr before present, which agrees in timing with other records from both the Alps and the sub-polar North-East Atlantic Ocean. The good temporal match of the warm periods determined for the central Alpine region with north-west European winter precipitation strength implies a strong and far-reaching influence of the North Atlantic Oscillation on continental European T variations during the Holocene. STUDY NOTES: Lake sediment bacterial lipids data and MBT/CBT temperature reconstruction from Lake Cadagno, Switzerland, for the past 11,000 years. Mean annual air temperature (MAAT) reconstruction is based on the MBT/CBT paleothermometer, utilizing temperature dependent distribution of specific bacterial membrane lipids in soil organic matter. Lake Cadagno, Switzerland: 46.5507°N, 8.7139°E, 1921m elevation. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Niemann, H. Investigator : Stadnitskaia, A. Investigator : Wirth, S.B. Investigator : Gilli, A. Investigator : Anselmetti, F.S. Investigator : Sinninghe Damsté, J.S. Investigator : Schouten, S. Investigator : Hopmans, E.C. Investigator : Lehmann, M.F. 2012-05-10 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/12909 https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/switzerland/cadagno2012.xls https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/switzerland/cadagno2012.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/switzerland/cadagno2012.xls https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/switzerland/cadagno2012.txt English https://www.ncdc.noaa.gov/paleo/study/12909 https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/switzerland/cadagno2012.xls https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/switzerland/cadagno2012.txt Niemann, H., A. Stadnitskaia, S.B. Wirth, A. Gilli, F.S. Anselmetti, J.S. Sinninghe Damsté, S. Schouten, E.C. Hopmans, and M.F. Lehmann. 2012. Bacterial GDGTs in Holocene sediments and catchment soils of a high Alpine lake: application of the MBT/CBT-paleothermometer. Climate of the Past, Vol. 8, pp. 889-906. www.clim-past.net/8/889/2012/ doi:10.5194/cp-8-889-2012 START YEAR: 10981 cal yr BP * END YEAR: -59 cal yr BP 8.7139 46.5507 8.7139 46.5507