Reconstructing past atmospheric circulation changes using oxygen isotopes in lake sediments from Sweden

Abstract

Here we use lake sediment studies from Sweden to illustrate how Holocene-aged oxygen isotope records from lakes located in different hydrological settings, can provide information about climate change. In particular changes in precipitation, atmospheric circulation and water balance. We highlight the importance of understanding the present lake hydrology, and the relationship between climate variables and the oxygen isotopic composition of precipitation ( δ¹⁸O_p) and lake waters (δ¹⁸O_lakewater) for interpretation of the oxygen isotopic record from the sediments (δ¹⁸O). Both precipitation reconstructions from Northern Sweden and water balance reconstructions from South and Central Sweden show that the atmospheric circulation changed from zonal to a more meridional airflow over the Holocene. Superimposed on this Holocene trend are δ¹⁸O_p minima resembling intervals of the negative phase of the North Atlantic Oscillation (NAO), thus suggesting that the climate of Northern Europe is strongly influenced by atmospheric and oceanic circulation changes over the North Atlantic.