An 1200-year multi-proxy dendrochronological temperature reconstruction for the area of Austrian Alps

Temperature reconstruction was carried out on the basis of a centuries-long dendrochronological scales from Austrian Alps. Chronologies of growth-ring width, maximum density of latewood and stable isotope content of carbon and oxygen were applied for the research. Subfossil wood and living trees originating from the area of Schwarzensee Lake were used for the construction of the chronologies. All measurements were performed with annual resolution. A very good match was found between the results obtained and the meteorological data, making it possible to precisely reconstruct the temperature of the growing season (May–September) over the years 800–2000 CE. The proportion of temperature variance explained by independent variables accounted for 52 % in the period common for the growth-ring chronologies and meteorological data. The statistics calculated during calibration and verification tests indicated that chronologies have high reconstruction skills and that the accuracy of reconstruction is good. Obtained data show the existence of significant cooling in the periods 900–1100 CE, 1275–1325 CE, 1450–1600 CE and 1800–1890 CE and evident warming around the years 1150 CE, 1250 CE, 1325–1425 CE, 1625–1775 CE. The strongest increasing trend in temperature has been observed since the beginning of the 20th century and is clearly indicative of an ongoing climate warming.