Ice-wedges as late Pleistocene winter paleoclimatic archives on Prins Karl Forland (RIS ID: 12313)

Apart from Greenland and Canadian Arctic ice-core records, late Pleistocene and Holocene paleoclimatic reconstructions in the northern latitudes are mainly based on proxies that record summer air temperatures. This seasonal bias has resulted in model-data mismatches, highlighting the need to reconstruct winter paleoclimate in the Arctic. Ice-wedges form in permafrost regions from the repetition of winter thermal contraction cracking in the ground and the filling of the cracks from snowmelt in the spring. As such, they preserve the isotopic composition of winter precipitation. A few studies have been successful at reconstructing paleoclimate from ice-wedges in Russia, Alaska and Arctic Canada. However, the potential of ice-wedges for paleoclimatic reconstructions remains largely unexploited, especially in the Svalbard. In this project, we suggest sampling ice-wedges that span through the late Pleistocene. We aim to establish ice-wedge chronology based on radiocarbon dating of plant macrofossils and dissolved organic carbon, and to measure the stable isotopic composition of winter precipitation (18O, D and d-excess), along with the soluble ion concentrations of the ice. Our dataset will be compared to the nearby ice-core records (Lomonosovfonna and Austfonna) and will provide a complementary high resolution winter climate archive at sea level in the periglacial landscape, dating back to the late Pleistocene. This will enable us to establish a novel environmental archive in Svalbard and provide new insight on how permafrost landforms respond differently across millennial-timescales. Our results are expected to provide a novel high-resolution dataset that will document a time-period that remains largely understudied. This dataset will also be useful for climate model validation in one of the most critical regions of the world to understand climate change.