Beschreibung: Comprenhending Antarctic coastal regions is fundamental to our understanding of the dynamic responses of the Antarctic ice sheet to ocean and climate warming.. These coastal regions contain multiple potential tipping points for the Antarctic Ice Sheet in a warming world, which must be better understood to predict the future magnitude and rates of global sea-level rise in a more robust fashion. The Antarctic Ice Sheet constitutes the largest uncertainty in future sea-level projections. 50 years of aereogeophysical observations have led to significant advances in our knowledge of bed topography and basal conditions and itheir influence on ice sheet dynamics. primarily in the interior of Antarctica Howevver, the critical coastal regions where the West and East Antarctic ice sheets meet the ocean and that are the sites of current and future change remain in many places insufficiently surveyed and understood.Here we present a new international initiative RINGS that aims to provide the first comprehensive pan-Antarctic wide coverage of the Antarctic coast mainly via new coordinated aerogeophysical campaigns. Together with an overview of the current multidisciplinary understanding of the Antarctic coastal regions, we present a new ensemble analysis of published datasets to present data coverage and knowledge gaps, and their regional distribution is discussed in the context of present ice-sheet dynamics and potential future change Finally, we identify outstanding science priorities and discuss protocols for new airborne surveys to develop a novel comprehensive dataset of Antarctic grounding zones (the main RING) and both landward and seaward RINGS all-around Antarctica.

Beschreibung: The mass balance of coastal Antarctica is significantly affected by warming in low-elevation areas. Summer melting in Antarctica can be a major concern in the warming climate scenario, but very few records exist for the coastal region. We present a 250-year ice core record of snow accumulation and summertime melting history from an ice core drilled at the summit of the Djupranen Ice Rise in coastal Dronning Maud Land, East Antarctica. Water-stable isotopes, visual stratigraphy, and major ion profiles were used to establish chronologies constrained by non-sea salt sulphate and tritium anomaly records. The melt index is calculated as the water-equivalent ratio of all melt layers in a year to total annual accumulation. The yearly average accumulation rate is 0.32 ± 0.14 m w.e. a〈sup〉-1〈/sup〉, while the yearly mean melt rate is 1 ± 1.25 %. The ice core record shows a significant decrease in snow accumulation rates in recent decades. Accumulation rates show high variability, with a significant decline since the 1980s. Annual melt was surprisingly higher in the pre-industrial era (before 1850 CE), averaging 1.3 % compared to 0.9 % in the present. We observed melting events in 184 out of 248 years, with the lowest melting period being 1796–1809. There is no correlation between ERA5 2m temperature and annual melt or δ〈sup〉18〈/sup〉O. In contrast, the ERA5 total precipitation trend is the opposite of annual snow accumulation from the ice core, suggesting a complex mechanism affecting the region's seasonal melting and snow accumulation rates.