Ice wedges as winter climate archives - towards high-quality chronologies, advanced process understanding and new paleoclimate records

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Ice wedges from Arctic permafrost regions are promising climate archives. In stable-water isotopes they preserve over millennia winter climate information that is not or only inadequately covered by other climate archives. This information,however, is essential for a comprehensive seasonal understanding of past climate variability.The proposed project aims at establishing ice wedges as climate archives and at providing new climate reconstructions. This will be achieved through a better understanding of the controlling processes and an advancement of methodical approaches. The project is based on an already existing set of ice-wedge data from several study sites in the Siberian Arctic and additional meteorological and isotope data.To derive better ice-wedge chronologies radiocarbon ages from different carbon fractions (macrofossil remains, dissolved, CO2) will be assessed and linked to local permafrost stratigraphies. Ice-wedge growth models will be developed to provide high-resolution ice-wedge isotope time series.The understanding of the ice-wedge isotope climate signal will be improved by the analysis of isotope fractionation during ice-wedge genesis. Considering local meteorological data ice-wedge isotope data will be calibrated to temperatures.By linking improved dating approaches and improved understanding of isotope signals new high-quality paleoclimate time series will be developed and interpreted considering other paleoclimate records and climate model output.