Sea ice is a fundamental component of the Earth's climate system. Changes in sea ice extent and thickness have a strong influence on albedo, the hydrologic cycle, ocean and air currents, ocean-atmosphere energy exchange, water mass stratification and formation, and biological productivity. Accurate documentation of past sea ice variations is a significant prerequisite for understanding the interactions between the ice, ocean, and atmosphere and their influence on climate change.
AWI has a long-standing expertise in micropaleontological and, more recently, biomarker-based reconstruction of sea ice, which provides important information on:
Knowledge of sea ice decline and expansion during past climate variability (e.g., during the Last Glacial Maximum, Deglacial, or Holocene) helps assess the role of sea ice as a driving mechanism for polar amplification of global climate change. In particular, complementary (multi-proxy) studies based on micropaleontological, sedimentological, and organic-geochemical methods allow a detailed investigation of ice-ocean-atmosphere feedback mechanisms and their influence on (pre)Quaternary climate variability. These data sets serve as a valuable basis for the synthesis of proxy and model approaches. At AWI, we use biomarkers (geochemical fossils) and fossil diatoms (diatoms) to reconstruct sea ice cover.