A brief review of palynological studies The western Arctic paleoenvironmental changes

Abstract

Recently, the Arctic environments have experienced dramatic and rapid changes. The most remarkable feature can be observed in the Arctic sea ice coverage, which shows rapid changes in its extent and thickness according to satellite observation during the last three decades. Recent rapid reduction in the sea ice extent is related to a major shift in the Arctic atmospheric and oceanic circulations, which plays a crucial role in regulating the global earth's climate. Of particular interest is the sea ice changes in the western Arctic, which is considered as a key parameter in past climate changes in Arctic and subarctic regions. They control the intensity and direction of sea ice drifts in the Beaufort Gyre and Transpolar Drift areas, and consequently regulate sea-ice and freshwater exports toward the North Atlantic. However, records of the past sea ice changes in the western Arctic especially on centennial to millennial scales have not been well-computed in climate models due to the rarity of suitable marine sedimentary records. Remnants of microscopic organisms in marine sediments such as spore, pollen and dinoflagellate cysts have been suggested as a useful tool for reconstructing paleoclimate changes in the western Arctic, inferring the past terrestrial environment and sea surface conditions such as sea surface temperature, sea surface salinity and the sea ice extent. In order to provide more complete and spatially extensive records of past sea ice conditions in the western Arctic, the spatial distribution of organic microfossil data sets and the accuracy of the environmental data need to be developed. This will enhance the reliability of the transfer function applied, which has been generally quite limited in the Arctic region.