| Summary: | 14th International Conference on Paleoceanography, 29 August - 2 September 2022, Bergen Paleodata of environmental responses to climate change from the Last Glacial Maximum (LGM) and the Holocene provide a useful performance test for climate models' sensitivity, contributing to better forecasts. Temporal high resolution data for both periods is important to reduce the uncertainties of models regionally.The Portuguese margin, one of the most productive marine regions of the world and having high sedimentation rates, is considered a key area to reconstruct past climate. This high temporal resolution study contributes with planktonic foraminifera (PF) data (fauna and stable isotopes), temperature and export productivity (Pexp) at two sites under different oceanographic conditions: MD03-2699 – off Estremadura spur and Shak-03-6K - off Sines. Preliminary results show that during the LGM, the average SSTs at the Estremadura was lower than Sines (12.3 °C vs. 19.4 °C) while the Pexp was higher (86.2 gC/m2/yr vs. 60.8 gC/m2/yr). In contrast, during the Mid Holocene (MH), at both sites, the average SSTs were warmer and the Pexp was lower than during the LGM (Estremadura - 18.9 °C, 76.1 gC/m2/yr; Sines - 21.2 °C, 55.2 gC/m2/yr). Subtropical and transitional PF species are abundant during the LGM reflecting warm, stable SSTs at both locations relative to the high mid-latitudinal North Atlantic (NA) sites, whereas higher Pexp was possibly caused by stronger westerly winds that enhanced the upwelling. SSTs at both sites during the MH were interrupted by a cold event (starting at 5.2 ky) coincident with a decrease in Pexp at both sites. This cold event could be related to the freshwater input from the melting Laurentide ice sheet, already observed in the NA. Pexp at the Estremadura was relatively higher than off Sines (~20 gC/m2/yr difference), probably because like today this site is under a stronger influence of upwelling events and riverine nutrient input from the Tagus River Peer reviewed
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