Tree-ring-based precipitation reconstruction in the south slope of the Qilian Mountains, northeastern Tibetan Plateau over the last millennium |
Paper ID : 1057-ADA2013 |
Authors: |
Junyan Sun *1, Yu Liu2 110 Fenghui South Road,Xi'an High-Tech Zone, Xi'an 210 Fenghui South Road,Xi'an High-Tech Zone, Xi'an |
Abstract: |
The tree-ring (Sabina przewalskii Kom.) based millennial precipitation reconstruction on the south slope of the middle Qilian Mountains in the northeastern margin of Tibetan Plateau, China, was reconstructed, which explained 48.5% of the variance in the instrumental precipitation from 1958 to 2004. The long-term precipitation variation patterns were confirmed based on the duration, magnitude and intensify of the multidecadal dry (wet) events. The multidecadal dry periods are 1092-1172, 1311-1351, 1441-1517, 1564-1730, 1814-1878. The wet periods are 1071-1091, 1230-1310, 1352-1440, 1518-1563, 1731-1813, 1879-1941 and 1978-2004. The multidecadal dry and wet events of SMQL have different patterns based on their events score. There are several stronger multidecadal dry periods, 1092-1172, 1441-1517 and 1564-1730, whereas only one outstanding severe wet event of 1352-1440. Comparisons with the glacier accumulation and dust content of Dunde ice core confirmed the reliability of the precipitation reconstruction in SMQL. Comparisons with other precipitation, runoff and PDSI reconstructions indicate that the precipitation in the northeastern Tibetan Plateau has similar variations over a large spatial and temporal range and the precipitation reconstruction in SMQL can represent the multidecadal scale moisture conditions in the northeastern Tibetan Plateau for the last millennia, especially during dry periods. The spatial extent of the great drought in the latter half of the 15th century also concentrated on the northeastern Tibet Plateau. These indicate that the moisture variations in the northeastern Tibetan Plateau are synchronous over a large spatial and temporal range in multidecadal scale for the last millennia, especially during dry periods. Wavelet analyses show that the precipitation variations for the last millennium may have some association with the solar activity on multidecadal to centennial scales. The correspondences between the low precipitation periods and the minimal solar activity periods further reveal the association with solar activity. |
Keywords: |
tree-ring width; Qilian Mountains; northeastern Tibetan Plateau; millennial precipitation reconstruction; drought |
Status : Abstract Accepted |