Abstract. The climate of east-central Europe (ECE) is the result of
a combination of influences originating in the wider North Atlantic realm,
the Mediterranean Sea, and the western Asian and Siberian regions. Previous studies have shown
that the complex interplay between the large-scale atmospheric patterns
across the region results in strongly dissimilar summer and winter conditions
on timescales ranging from decades to millennia. To put these into a wider
context, long-term climate reconstructions are required, but, largely due to
historical reasons, these are lacking in ECE. We address these issues by
presenting a high-resolution, radiocarbon-dated record of summer temperature
variations during the last millennium in ECE, based on stable isotope
analysis of a 4.84 m long ice core extracted from Focul Viu Ice Cave
(Western Carpathians, Romania). Comparisons with both instrumental and
proxy-based data indicate that the stable isotope composition of cave ice
records the changes in summer air temperature and has a similar temporal
evolution to that of the Atlantic Multidecadal Oscillation on decadal to
multidecadal timescales, suggesting that changes in the North Atlantic
are transferred, likely via atmospheric processes towards the wider Northern Hemisphere. On centennial timescales, the data show little summer temperature differences between the Medieval Warm Period (MWP) and the Little Ice Age (LIA) in eastern Europe. These findings are contrary to those that show a marked contrast between the two periods in terms of both winter and annual air temperatures, suggesting that cooling during the LIA was primarily the result of wintertime climatic changes.
Wavelet analysis of low-frequency variability in oak tree-ring chronologies from east Central Europe