The Late Quaternary Paleoenvironmental changes in the high altitude North Atlantic based on foraminiferal record

Abstract

newline The Subpolar North Atlantic (SPNA) Ocean plays a vital role in the global climate newlinesystem as it is associated with deep-water formation, modulating the Atlantic newlineMeridional Ocean Circulation (AMOC). AMOC is the term used for circulation newlineinvolving the transformation of warm surface Atlantic water to cold deep water. newlineThe SPNA ocean displays a surface hydrographic variation by the interaction of newlinevarious surface and deep water currents such as the North Atlantic Current, East newlineGreenland Current, Labrador Current, Deep western boundary current, etc. newlineMoreover, the North Atlantic Oscillation and subpolar gyre dynamics shape the newlineupper watermass structure through complex ocean-atmosphere interactions. These newlinevariations in SPNA hydrography have been linked to the variation in AMOC newlinestrength both from modern observations and paleo studies. Hence, the SPNA ocean newlinecarries substantial significance in moderating the global climate and thus is the newlinerequisite for understanding past hydrographic variations in the SPNA. Since newlinemodern conditions are a continuation of the Holocene epoch, it provides the best newlineframework to study the hydrographic variability of the SPNA and the associated newlinefactors. Due to their omnipresent characteristics, good preservation, sensitivity to newlinesubtle environmental changes, and preference for specific watermass habitats, newlineplanktic foraminifera are among the best paleo-proxies for surface hydrography newlinereconstruction. In the present study, Holocene SPNA hydrographic variations have newlinebeen reconstructed using planktic foraminifera proxies from a sediment core in the newlineSPNA ocean, southwest of Iceland. Additionally, the modern distribution of the newlineplanktic foraminifera assemblages in the region has been explored using surface newlinesediment samples collected along an east-west transect at 59.5°N. newlineThis study documents a significant variation in the planktic foraminiferal newlineassemblages in the SPNA ocean from east to west, influenced by the regional newlinehydrography. A clear gradient has been displayed esp