Publication details

Tree rings reveal hydroclimatic fingerprints of the Pacific Decadal Oscillation on the Tibetan Plateau

Authors	LYU Lixin BÜNTGEN Ulf TREYDTE Kerstin YU Kailiang LIANG Hanxue REINIG Frederick NIEVERGELT Daniel LI Mai-He CHERUBINI Paolo
Year of publication	2019
Type	Article in Periodical
Magazine / Source	Climate Dynamics
MU Faculty or unit	Faculty of Science
Citation
Web	https://link.springer.com/article/10.1007/s00382-019-04629-z
Doi	http://dx.doi.org/10.1007/s00382-019-04629-z
Keywords	Climate dynamics; Dendroclimatology; Drought extremes; Hydroclimate; Proxy reconstruction; Relative humidity; Tree rings
Description	Predicting hydroclimatic changes on the Tibetan Plateau (TP) is crucial for managing water and ecosystems for the well-being of millions of people. Our understanding of the synoptic conditions on the TP is, however, still limited due to the paucity of meteorological measurements and proxy-based, high-resolution climate reconstructions. Here, we use state-of-the-art dendroclimatological techniques to investigate the paleoclimatic potential of drought-sensitive Picea likiangensis var. balfouriana forests between 4000 and 4500m asl on the southeastern TP (SETP). The newly developed tree-ring width chronology correlates significantly with yearly changes in regional relative air humidity (RH) (r=0.85, P<0.001, 1978-2011). A new 407-year-long reconstruction of RH over the hydrological year from previous year August to July of the year of ring formation shows that, despite the generally humid conditions, four of the ten driest years are observed in the twentieth century with 1983 having been the driest. On the other hand, seven out of the ten most humid years were found in the eighteenth century. Our reconstruction reveals that the Pacific Decadal Oscillation (PDO) is the dominant climate driver at multi-decadal scales, but the relationships are not stable over time, with unknown underlying mechanisms. Although our study demonstrates the importance of the PDO for hydroclimate projections on the TP, caution is advised when considering only its most recent fluctuations.