Variation of early summer and annual temperature in east Taymir and Putoran (Siberia) over the last two millennia inferred from tree rings

Regional tree ring chronology with extension 2209 years (from 212 B.C. till 1996 A.D.) was built for east Taymir and Putoran according to wood of living trees, well- preserved remains of dead trees, and subfossil wood from alluvial bank deposits by the cross-dating method. In addition, the "floating" tree ring width chronology for the period of Holocene optimum (3300-2600 B.C.) was built with extention 685 years and supported by several radiocarbon dates. High values of synchrony and correlation of individual tree ring series show a prevailing effect of one external factor on radial tree growth change in the studied region of the Siberian subarctic. It was established that the main factors of growth variability are the early summer and annual temperature, which explain up to 70% of tree growth rate variability. Cyclic components stable for two millennia were revealed at analysis of the tree ring chronology: double secular (similar to 180 years), secular (78-90 years), and intrasecular (44, 28, 11, and 6.7-6.9 years) variations. Models for reconstruction of the early summer and annual air temperature were obtained according to tree ring variability. Temperature dynamics in the eastern part of Taymir for the last two millenia agree well with temperature variations in the Northern Hemisphere obtained according to other indirect sources. The warming of the middle of the twentieth century is not extraordinary. The warming at the end of the first and beginning of the second millennia ("Medieval Warm Period") was longer in time and closer in amplitude.