Twentieth-century warming preserved in a Geladaindong mountain ice core, central Tibetan Plateau

Abstract

High-resolution δ 18 O records from a Geladaindong mountain ice core spanning the period 1477-1982 were used to investigate past temperature variations in the Yangtze River source region of the central Tibetan Plateau (TP). Annual ice-core δ 18 O records were positively correlated with temperature data from nearby meteorological stations, suggesting that the δ 18 O record represented the air temperature in the region. A generally increasing temperature trend over the past 500 years was identified, with amplified warming during the 20th century. A colder stage, spanning before the 1850s, was found to represent the Little Ice Age with colder periods occurring during the 1470s-1500s, 1580s- 1660s, 1700s-20s and 1770s-1840s. Compared with other temperature records from the TP and the Northern Hemisphere, the Geladaindong ice-core record suggested that the regional climate of the central TP experienced a stronger warming trend during the 20th century than other regions. In addition, a positive relationship between the Geladaindong δ 18 O values and the North Atlantic Oscillation index, combined with a wavelet analysis of δ 18 O records, indicated that there was a potential atmospheric teleconnection between the North Atlantic and the central TP.