Holocene paleo-environments from the southeastern Barents Sea will be studied to track past changes in water and sea-ice characteristics on a century to interdecadal scale. Noticeable ongoing changes in the Arctic natural system require better understanding of mechanisms controlling this change. In particular, it is critical to assess variations in Arctic-Atlantic climatic interactions in a long-term perspective. The Barents Sea has been identified as a key area for investigating these variations. A distinct atmospheric and hydrographic boundary between Arctic and Atlantic domains crosses the Barents Sea, and its bottom sediments record fluctuations in the position of this boundary. Selected sediment cores, recently collected in the southeastern Barents Sea in areas with elevated sedimentation rates, will be investigated for paleobiological, mineralogical, grain-size, and geochemical composition. Obtained proxy data will allow the estimation of Holocene variations in surface and bottom water temperatures and salinities, sea-ice conditions, and circulation patterns. Core stratigraphy will be time-constrained by AMS 14C dating of selected calcareous faunal remains. A resolutions of 100-120 yr is expected in the open Barents Sea, and up to 30-50 yr in the adjacent Kola Bay. The study results will test the existence of long-term fluctuations in Arctic-Atlantic interactions, a cornerstone for understanding modern Arctic climatic changes.