Leonid Polyak

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  Paleo-perspective of the development of sea ice and related biota in the Arctic Ocean
  Leonid Polyak
  The Arctic environment is experiencing a rapid change due to the ongoing climate warming, with an especially high rate of temperature increase in the Arctic. The core of this change is the cryosphere destruction: an abrupt decrease in sea ice extent and volume, intensified glacier melting, and degradation of the permafrost. These processes profoundly affect the entire Arctic natural system including cascading effects on the Arctic Ocean food web. Recent years have witnessed changes in biogeochemical cycling and primary production patterns in various parts of the Arctic Ocean and intrusions of low-latitude biota into the high Arctic. For a proper evaluation of these changes and their future projection, they need to be considered in the context of long-term development of the Arctic environments beyond the scope of historical observations. Sediments from the Arctic Ocean floor hold the long-time archive of the history of sea ice, oceanic circulation, and related biological conditions. Investigation of sediment cores collected from multiple sites across the Arctic Ocean provide insights into paleoceanographic variations during the last several 100,000 years, with a yet longer-time record now available from a central Arctic Ocean site. In this talk I will give an overview of these geological studies with a focus on implications for the development of sea ice and effects on the Arctic Ocean biota.