July Mean Temperature Reconstruction for the Southern Tibetan Plateau Based on Tree-Ring Width Data during 1763–2020

Abstract

Long-term climate records are essential for understanding past climate change and its driving forces, which could provide insights for adapting to future climate change. This paper presents a reconstruction of the July mean temperature based on the Smith fir tree-ring width data over 1763–2020 for the southern Tibetan Plateau (TP). The reconstruction explained 50.1% of the variance in the instrumental temperature records during the calibration period 1979–2020. The reconstruction matched well with other summer temperature reconstructions from neighboring regions and Northern Hemisphere temperatures. A significant warming trend was found from the 1960s, and the warming accelerated since the 1990s. In the reconstructed series, multiple-taper method analysis and wavelet analysis revealed significant periodicities of 2–4-year, 20–30-year, and 70–80-year. Moreover, the El Niño Southern Oscillation (ENSO) and the Atlantic Multidecadal Oscillation (AMO) significantly influenced the July mean temperature in our study area. Our reconstruction can provide valuable data for climate change studies.