A comparison of pre-Millennium eruption (946 AD) and modern temperatures from tree rings in the Changbai Mountain, northeast Asia.

High-resolution temperature reconstructions 19 in the prior millennium are limited in northeast Asia, but important for assessing regional climate dynamics. Here, we present, for the first time, a reconstruction of April temperature for ~300 years before the Millennium volcanic eruption in 946 AD, using tree rings of carbonized logs buried in the tephra in Changbai Mountain, northeast Asia. The reconstructed temperature changes were consistent with previous reconstructions in China and Northern Hemisphere. The influences of large-scale oscillations (e.g., El Niño-Southern Oscillation) on temperature variability were not significantly different between the period preceding the eruption and that of the last ~170 years. However, compared to the paleotemperature of the prior millennium, the temperature changes were more complex with stronger temperature fluctuations, more frequent temperature abruptions, and a weaker periodicity of temperature variance during the last one and half centuries. These recent changes correspond to long-term anthropogenic influences on regional climate. [ABSTRACT FROM AUTHOR]