Marine and ice core reconstruction of East Antarctic sea ice variability over the past 2,000 year

The Antarctic seasonal sea-ice cycle is important for the ocean-atmosphere heat and gas exchange, the formation of deep waters that affect the global oceanic circulation and natural carbon cycle, and the regional and global nutrient distribution and primary productivity. Over the past 30 years, sea ice in the Arctic or West Antarctica has been declining. In contrast, there has been a significant increase of East Antarctic sea ice, dominated by sea ice trends the Ross Sea region. Since 2016, however, we observe an unexplained, rapid decline in sea ice in the Ross Sea. The causes of such dichotomy in recent climate evolution remain enigmatic, because satellite and gridded reanalysis data only capture the period from 1979 to today. The brevity of time series also limits the ability of earth system models to adequately capture observed Antarctic sea ice trends. Consequently, future sea ice projections are highly uncertain. High-resolution investigation of past Antarctic sea-ice conditions prior to the industrial period provide an important opportunity to improve our understanding of the interaction between sea ice and other compartments of the climate system (atmosphere, ocean, ice shelves, biogeochemical cycling, primary production) under natural forcing and warmer-than-present climate. An emerging array of Antarctic ice core records (Stenni et al. 2018) provide insights into atmospheric and surface ocean processes at high resolution. In addition, the emerging high resolution records along the Ross Sea and Wilkes Land coast afford now for the first time an ice core / marine sediment record correlation to extend the instrumental record beyond 1979. This project aims to take advantage of two exceptionally well dated and highly resolved ice core and marine sediment records from critical locations to provide the first Ross Sea / Wilkes Land sea ice reconstruction for the past 1,000 years.