Greenland ice cores as proxy for European extremes

High-resolution ice core data from the Greenland Ice Sheet offer valuable insights into past climate variations on seasonal to multidecadal scales. One key parameter for reconstructing these variations is the concentration of stable oxygen isotopes in ice cores. We present evidence that a stacked record of stable oxygen isotope concentrations from Northern Greenland ice cores is a good proxy for the recurrence of a particular synoptic patterns in the atmospheric circulation, such as atmospheric blocking. Our evidence indicates that low oxygen isotope concentrations corroborate the reoccurrence formation of high-pressure systems over Europe. In particular, during the observational period (1920 – 2011), an increase in the frequency of atmospheric blocking events from Iberian Peninsula to Scandinavia is observed, leading to significant shifts in European hydroclimatic conditions: increased precipitation along the Norwegian coast, drier conditions and decreased temperatures in southern Europe. These findings are supported by a paleo-reanalysis product, which indicates similar patterns over a longer temporal perspective (1602 – 2003).