Climatic-oceanographic controls on Amundsen Sea productivity and bottom flow evolution since 280 ka

Understanding the mechanisms regulating productivity and bottom flow variability in the Amundsen Sea is vital for constraining cryosphere-climate feedbacks in the South Pacific Seasonal Sea Ice Zone. To enhance our comprehension of the mechanisms underlying productivity variations in this region, we present an extensive set of multi-proxy records from gravity core ANT36/A3-08 (LATITUDE: -69.02 and LONGITUDE: -120.06), retrieved from the southernmost upwelling boundary of the modern Circumpolar Deep Water in the Amundsen Sea. Surface productivity is reconstructed using a suite of biogeochemical proxies, including Ti-normalized bromine, biogenic opal, total nitrogen, and excess barium normalized to Ti. These proxies reflect marine biogenic export production and nutrient cycling. Bottom flow strength is inferred from sedimentological and geochemical indicators such as mean sortable silt, sortable silt percentage, zirconium-to-rubidium, and zirconium-to-aluminum ratios.