A 479-Year Early Summer Temperature Reconstruction Based on Tree-Ring in the Southeastern Tibetan Plateau, China

Yu Zhang,Jinjian Li,Shenglan Zeng,Zeyu Zheng

doi:10.3390/atmos12101251

Abstract

Due to the lack of long-term climate records, our understanding of paleoclimatic variability in the Tibetan Plateau (TP) is still limited. In this study, we developed a tree-ring width (TRW) chronology based on tree-ring cores collected from our study site, southeastern TP. This chronology responded well to the mean maximum temperatures of May–June and was thus used to reconstruct early summer (May–June) maximum temperature during the period 1541–2019. The reconstruction explained 33.6% of the climatic variance during the calibration period 1962–2019. There were 34 extremely warm years (7.2% of total years) and 36 extremely cold years (7.5% of total years) during the reconstruction period. The spatial correlation analysis and the comparison with other local temperature reconstructions confirmed the reliability and representativeness of our reconstruction. The results of the ensemble empirical mode decomposition (EEMD) analysis indicated quasi-oscillations of 2.9–4.2 years, 4.5–8.3 years, 11.1–15.4 years, 20–33.3 years, 50.4 years, 159.7 years, and 250 years in this temperature reconstruction which may be associated with ENSO cycles, solar activity, and PDO.

Highlights

Global warming has significant impacts on the forest ecosystem, natural resources, and social economy, such as through land degradation, landslides and the retreat of glaciers [1]
The significant correlation (p < 0.05) only occurred in July of the current year. These results suggested that the temperature is the main controlling factor for the tree-ring change in our study area
We presented a 479-year May–June maximum temperature reconstruction for the southeastern Tibetan Plateau (TP) based on a new tree-ring width chronology of Picea balfouriana

Summary

Introduction

Global warming has significant impacts on the forest ecosystem, natural resources, and social economy, such as through land degradation, landslides and the retreat of glaciers [1]. Climate reconstructions based on tree-ring data originating from the TP have been widely developed, including temperature [8,9,10,11,12,13], precipitation/drought [14,15,16,17] and river runoff [18,19,20]. Duan and Zhang [23] reported the reconstruction of the April–September mean temperature over the past 449 years on the southeastern TP and explored its relation to solar activity All of these studies found the possible links between the tree-ring growth and large-scale atmospheric circulation systems. The high sensitivity of the tree-ring width (TRW) chronology to early summer maximum temperature allows us to develop a reliable reconstruction to perceive regional early summer maximum temperature variations during the past five centuries and to investigate the possible driving factors that influence the temperature variability on the southeastern TP

Methods

Results

Discussion

Conclusion