A late-Holocene multi-proxy record from the northern Norwegian margin: Temperature and salinity variability

• Published in: The Holocene
• Main Authors: Berben, Sarah MP, Husum, Katrine, Aagaard-Sørensen, Steffen
• Other Authors: Changing Arctic and Subarctic Environments (CASE ITN), EU 7th Framework Program People, UiT - The Arctic University of Norway, Norwegian Polar Institute
• Format: Article in Journal/Newspaper
• Language: English
• Published: SAGE Publications 2016
• Subjects: Paleontology; Earth-Surface Processes; Ecology; Archeology; Global and Planetary Change; Neogloboquadrina pachyderma; North Atlantic; North Atlantic oscillation
• Online Access: http://dx.doi.org/10.1177/0959683616675934; http://journals.sagepub.com/doi/pdf/10.1177/0959683616675934; http://journals.sagepub.com/doi/full-xml/10.1177/0959683616675934

To elucidate the natural variability of Atlantic and Coastal water, a late-Holocene multi-proxy analysis is performed on a marine sediment core from the northern Norwegian margin. This includes planktic foraminiferal fauna and their preservation indicators, stable isotopes (δ 18 O c , δ 13 C), sub-surface temperature (SST Mg/Ca ) and salinity (SSS) records based on paired Mg/Ca and δ 18 O c measurements of Neogloboquadrina pachyderma and transfer function–derived sub-surface temperatures (SST Transfer ). The record shows a general cooling with subtle fluctuating palaeoceanographic conditions, here attributed to shifting North Atlantic Oscillation (NAO) modes. Period I (ca. 3500–2900 cal. yr BP) is strongly influenced by Coastal water and stratified water masses, possibly correlating to negative NAO conditions. During period II (ca. 2900–1600 cal. yr BP), dominating warm Atlantic water might be linked to a positive NAO mode and the Roman Warm Period. A renewed influence of Coastal water is observed throughout period III (ca. 1600–900 cal. yr BP). Stable and colder SST values potentially correlate to the Dark Ages and are here attributed to negative NAO conditions. Within period IV (ca. 900–550 cal. yr BP), the core site experienced a stronger influence of Atlantic water which might be because of the positive NAO conditions correlating to the ‘Medieval Warm Period’. Additionally, an inverse correlation in Atlantic water influence between the eastern and western Atlantic Ocean is observed throughout periods II, III and IV. This Atlantic oceanographic see-saw pattern is attributed to an opposite climatic response to changing NAO conditions arguing for a coupling between ocean and atmosphere.