Reconstructed summer Palmer Drought Severity Index since 1850 AD based on δ13C of larch tree rings in eastern Siberia

• Summer PDSI was reconstructed for the central part of East Siberia using tree rings.
• The reconstruction captured extreme events of wet and dry conditions.
• Regional comparison suggested synchronous year-to-year changes in moisture condition.
• Decadal moisture variability was rather heterogeneous within the region.
• Regional studies improve the estimates for global changes in hydrological conditions.

SummaryWe present a tree-ring reconstruction of Palmer Drought Severity Index (PDSI) in Ust-Maya region (60°00′N, 133°49′E), central part of eastern Siberia using total ring (TR) widths and latewood (LW) δ13C chronologies from larch trees (1850–2008 AD). Summer (JJA) PDSI was correlated positively and negatively with the TR widths and LW δ13C, respectively. Using a multiple liner regression approach, we reconstructed summer PDSI using the time series of TR widths and LW δ13C. The reconstruction showed an interannual to decadal wet/dry fluctuation with several moist periods before 1950s and a severe drought event from 1991 to 1993. Comparison of the reconstruction with reconstructed July PDSI for the Yakutsk region, 300 km northwest of Ust-Maya, showed heterogeneous changes in the mean states of soil moisture, but synchronous year-to-year changes. These results indicate that regional studies are quite important to precisely depict the spatio-temporal variability of hydrological changes in the central part of eastern Siberia.