A 368-year maximum temperature reconstruction based on tree ring data in northwest Sichuan Plateau (NWSP), China

摘要

We present a reconstruction of July–August mean maximumtemperaturevariabilityfornorthernWest Sichuan Plateau(NWSP), Chinabased on a chronology of tree-ringwidthsover the period1646–2013AD.A regression modelexplains 37.1 % of the variance of July–August mean maximumtemperature during the calibration period from 1954to 2012. Sevenmajor cold periods were identified including 1708–1711, 1765–1769, 1818–1821, 1824–1828, 1832–1836, 1839–1842and 1869–1877, and three major warm periods occurred between 1655–1668, 1719–1730 and 1858–1859in our reconstruction. Comparison with other nearby temperature reconstructions and spatial correlations with gridded land surface temperature datesrevealedthatour temperaturereconstructionhas high spatial representativeness.20th century rapidwarming wasn’t obvious in the NWSP mean maximumtemperature reconstruction, which implied that mean maximum temperature might play an important and different role in global change asunique temperature indicators. Multi-taper method (MTM) spectral analysis revealed significantperiodicities of170-, 49–114-, 25–32-, 5.7-, 4.6–4.7-, 3.0–3.1-, 2.5- and 2.1–2.3-year quasi-cycles at a 95 % confidence level. The mean maximum temperature variability in northwest Sichuanmay be affected by ENSO, PDO, AMO and solar activity.