摘要

Long-term summer temperature records are important for climate studies on the Tibetan Plateau (TP). Here, we used tree-ring maximum latewood density (MXD) to develop a well-replicated regional chronology back to the year 1630 for the southeastern TP. The MXD chronology is positively related to the observed August mean minimum temperatures (AMMT) in the period 1961-2011. Therefore, the AMMT was reconstructed from the MXD chronology. The reconstruction explained 42.6% of the total variance in the observed AMMT. During the past 382 years, warm periods were found during 1646-1694,1770-1805, 1930-1971 and 1992-2011, and cold periods were found during 1630-1645, 1695-1749, 1806-1825, 1889-1929 and 1972-1991. Extreme cold summers (<= mean - 2 SD) occurred in the years 1701, 1777, 1810, 1817, 1835, 1843, 1857, 1871, 1911, 1914, 1915, 1939, 1983 and 1984, whereas the warm summers (>= mean+2 SD) occurred in the years 1786, 1788, 2003, 2004 and 2005. A comparison with temperature records in surrounding regions showed general agreements, indicating the fidelity of our reconstruction and its ability to represent summer temperature variations over a broad geographic extent. Conspicuous in-phase relationships between our reconstruction and the Atlantic Multidecadal Oscillation (AMO) indicated a strongly positive association between large-scale climate circulations and summer temperature variability on the southeastern TP at multidecadal scales.