A new tree-ring-based summer temperature reconstruction over the last three centuries for east-central Europe

摘要

Tree rings and documentary evidence are the most important palaeoclimatic archives with annual resolution that continuously span several centuries. Despite this benefit, local to regional-scale temperature reconstructions and their spatial signatures tend to be irregularly distributed, and the appropriate extent of low-frequency variability captured in these proxy records remains uncertain. Here, the first summer temperature reconstruction from the Czech Sudetes Mountains that extends to 1700 AD was introduced. An ensemble reconstruction approach using 251 new high-elevation spruce ring width samples suggests particularly cold June-July temperatures at the beginning of the 18th century, in the 1740s and around 1820. Markedly warm conditions occurred in the 1790s and during the most recent decades. The reconstructed decadal summer temperature amplitude from Little Ice Age Cooling' to Recent Anthropogenic Warming' ranges from -3.5 degrees C between 1700 and 1710 to 1.3 degrees C in 1999-2009, with respect to the 1961-1990 mean climatology. Comparison of our new reconstruction with existing tree-ring chronologies from the Alps reveals a significant level of coherency that is much higher than the agreement with geographically closer documentary evidence from Central Europe. Our study confirms the importance of independent regional climate reconstructions, which capture the full range of past variability and also fill spatial gaps in large-scale networks.