BrGDGTs-based temperature and hydrological reconstruction from loess-paleosol deposits in the Eastern European Plain since 200 ka

Knowledge of glacial-interglacial changes in the temperature-humidity configuration of Eastern Europe can provide insights into the regional climate changes in response to ongoing global warming. Here, we present temperature and humidity (soil pH) reconstructions since 200 ka based on records of branched glycerol dialkyl glycerol tetraethers (brGDGTs) for the Strelitsa and Beglitsa loess sections located in the central and southern Eastern European Plain (EEP), respectively. The reconstructed temperatures ranged from 10 to 17 degrees C in the Strelitsa section and varied between 8 and 19 degrees C in the Beglitsa section over glacial-interglacial cycles. The reconstructed soil pH in the Strelitsa and Beglitsa sections ranged from 6.1 to 7.8 and from 6.6 to 8.6, respectively, indicating wet conditions during MIS 7 and MIS 1, relatively humid conditions during the interstadials of MIS 6 and MIS 5d-5a, and dry conditions during MIS 5e and the last glacial period. By correlating with climatic records from Eastern Europe, we find that the spatial-temporal distribution of humidity in the central and southern EEP was in line with the meridional shift of the northern westerlies on the orbital time scale. We suggest that the northern westerlies maximum was located over the central and southern EEP, which brought abundant moisture during the interstadials (MIS 6 and MIS 5d-5a) and relatively cool interglacials (MIS 7 and MIS 1), whereas it shifted southward and northward during cold glacial periods and warm MIS 5e, respectively, thereby leading to dry conditions in the central and southern EEP. In this context, the central and southern EEP will become dry in response to the ongoing global warming.