Seasonal climate variations in the Baltic Sea during the Last Interglacial based on foraminiferal geochemistry

TY - JOUR

T1 - Seasonal climate variations in the Baltic Sea during the Last Interglacial based on foraminiferal geochemistry

AU - Ni, S.

AU - Quintana Krupinski, N. B.

AU - Chonewicz, J.

AU - Groeneveld, J.

AU - Knudsen, K. L.

AU - Seidenkrantz, M. S.

AU - Filipsson, H. L.

N1 - Publisher Copyright: © 2021 The Authors

PY - 2021/11

Y1 - 2021/11

N2 - Climate during the Last Interglacial period (LIG, Marine Isotope Stage 5e) was on average warmer than the present, with a higher global sea level but also more unstable conditions. Today, the Baltic Sea interacts strongly with conditions in the North Atlantic region, and this interaction was likely even stronger during the LIG. We here present a reconstruction of seawater conditions during the LIG based on benthic foraminiferal geochemistry (stable isotopes and trace elements) and compare these records with modern marine monitoring data to evaluate seasonal hydrographic conditions in the western and southern Baltic Sea during the first half of the LIG (130–123 ka BP). Our reconstructions reflect the evolution of seasonal temperature and salinity, rather than annual mean conditions. The spring LIG bottom water temperatures in the Skagerrak and Kattegat were ∼2–3 °C higher compared to the modern spring bottom water temperatures. During the LIG, there was an increase in seasonality in bottom water temperature (progressively warmer summers and cooler springs) in the southern Baltic Sea, which can be linked to seasonal insolation changes. Moreover, our data suggest a decreased gradient of bottom water salinity along a transect through the Skagerrak-Kattegat-Danish Straits-southern Baltic Sea, supporting previous investigations inferring a stronger ocean-water influx into the Baltic Sea during the LIG than at present.

AB - Climate during the Last Interglacial period (LIG, Marine Isotope Stage 5e) was on average warmer than the present, with a higher global sea level but also more unstable conditions. Today, the Baltic Sea interacts strongly with conditions in the North Atlantic region, and this interaction was likely even stronger during the LIG. We here present a reconstruction of seawater conditions during the LIG based on benthic foraminiferal geochemistry (stable isotopes and trace elements) and compare these records with modern marine monitoring data to evaluate seasonal hydrographic conditions in the western and southern Baltic Sea during the first half of the LIG (130–123 ka BP). Our reconstructions reflect the evolution of seasonal temperature and salinity, rather than annual mean conditions. The spring LIG bottom water temperatures in the Skagerrak and Kattegat were ∼2–3 °C higher compared to the modern spring bottom water temperatures. During the LIG, there was an increase in seasonality in bottom water temperature (progressively warmer summers and cooler springs) in the southern Baltic Sea, which can be linked to seasonal insolation changes. Moreover, our data suggest a decreased gradient of bottom water salinity along a transect through the Skagerrak-Kattegat-Danish Straits-southern Baltic Sea, supporting previous investigations inferring a stronger ocean-water influx into the Baltic Sea during the LIG than at present.

KW - Benthic foraminifera

KW - Hydrography

KW - Seasonality

KW - The Baltic Sea

KW - The Last Interglacial

KW - The Skagerrak

UR - http://www.scopus.com/inward/record.url?scp=85116604885&partnerID=8YFLogxK

U2 - 10.1016/j.quascirev.2021.107220

DO - 10.1016/j.quascirev.2021.107220

M3 - Journal article

AN - SCOPUS:85116604885

SN - 0277-3791

VL - 272

JO - Quaternary Science Reviews

JF - Quaternary Science Reviews

M1 - 107220

ER -