Variability of the Early Summer Temperature in the Southeastern Tibetan Plateau in Recent Centuries and the Linkage to the Indian Ocean Basin Mode

Abstract

Abstract Although many temperature time-series reconstructions, constructed on the basis of tree-ring widths, with lengths of centuries to millennia have been published for many parts of the southeastern Tibetan Plateau (SETP), field reconstruction has been unaddressed to date. Here, we present a tree-ring network comprising 53 chronologies (one δ13C chronology, one regional maximum latewood density chronology, and 51 width chronologies). Using the modified point-by-point reconstruction method, a temperature field consisting of data from 28 meteorological stations in the SETP over the past 200–500 y (the common period was from 1730 to 1998; the longest single period was from 1480 to 2002) was reconstructed. Principal component analysis and rotated principal component analysis results indicated that the reconstructed temperature field may be representative of spatial distribution characteristics. The temperature changes in the SETP were similar. The correlation coefficients between the reconstructed regional average temperature and each observed series were 0.44–0.83 (86% were greater than 0.6, and all the significance tests reported a level of 0.01). Temperature changes were mainly synchronous with those in the middle and low latitudes of the Northern Hemisphere. We then explored the influence of possible climatic forcing and found that the Indian Ocean Basin mode may be a principal factor controlling the interannual variations in the STEP summer temperatures.