A 449 year warm season temperature reconstruction in the southeastern Tibetan Plateau and its relation to solar activity. Issue 20 (22nd October 2014) - Duan, Jianping
Abstract There is a close relationship between solar activity and the Earth's surface temperature, but this relationship has weakened with recent global warming. To better understand this puzzle, temperature records need to be extended, and the relationship between long‐term variation in temperature and solar activity needs to be examined. In this study, we reconstruct April–September temperature variation back to 1563 using tree ring maximum late wood density (MXD) data from Balfour spruce in the southeastern Tibetan Plateau (TP). Spatial correlation analysis indicates that our reconstruction is representative of temperature variability over the large‐scale TP. On the 22 year time scale, the reconstructed April–September temperature corresponds generally to solar activity over the past three centuries. Spectral analyses also indicate that the significant periodicities of ~11 years, 54 years, and 204 years observed in the MXD chronology correspond to the Schwabe cycle, the fourth harmonic of the Suess cycle, and the Suess solar cycle, respectively. However, disparities between temperature change and solar activity are identified in two periods, the 1880s–1900s and the 1980s–present. These results suggest that solar forcing is the critical driver for long‐term temperature variability in the TP, but other factors may uncouple surface temperature and solar activity in some periods. One possible cause of the weak effect of solar activity on temperature during the 1880s–1900s is internal climate variability, while human‐activity‐induced greenhouse gas emissions have likely superseded solar forcing as the major driver of the rapid warming observed since the 1980s.