Paleoceanographic Proxies in the Northern North Atlantic

The advantages and limitations of various proxy indicators of physical boundary conditions, such as sea-surface temperature (SST) and salinity (SSS), circulation patterns, deep-water ventilation, nutrient cycles and the response of the biota (productivity and carbon-flux), have been investigated in the Greenland-Iceland-Norwegian (GIN) Seas. Low sea-surface temperatures, the presence of sea ice, strong seasonality and vigorous thermohaline circulation in this area cause severe difficulties for the application of several classical temperature, salinity, nutrient and flux proxies. Quantitative estimates are provided for temperature, salinity and the seasonal duration of seaice cover, although margins of error are still larger than in the North Atlantic south of Iceland. However, proxies based on benthic foraminifera, reflecting biotic processes at the benthic boundary layer (i. e. assemblage composition and isotopic signals of benthic foraminifera), exhibit potential as indicators of seasonal carbon flux and deep-water ventilation in the Greenland-Iceland-Norwegian Seas.