摘要
The annually cross-dated stable carbon isotope of tree-ring a-cellulose of Abies spectabibis collected from the southeastern Tibetan Plateau is used to examine its rela-tionship with climatic parameters. The residual D13C series in treerings is constructed after removing the effects of age trend and rising CO2. We found a close relationship between D13C in tree rings and the relative humidity of September—November of the previous year measured at the nearby Ny-ingchi Meteorological Station, albeit a strong 搇agged effect? Thus we developed a transfer function to reconstruct the autumn relative humidity for the Nyingchi region, which explained 37.9% of the total variance (p < 0.001). Our results suggest a high frequency and moderate amplitude variance of the relative humidity before 1800, and the variance re-versed afterwards.
The annually cross-dated stable carbon isotope of tree-ring α-cellulose ofAbies spectabibis collected from the southeastern Tibetan Plateau is used to examine its relationship with climatic parameters. The residual Δ13C series in treerings is constructed after removing the effects of age trend and rising CO2. We found a close relationship between Δ13C in tree rings and the relative humidity of September-November of the previous year measured at the nearby Nyingchi Meteorological Station, albeit a strong “lagged effect”. Thus we developed a transfer function to reconstruct the autumn relative humidity for the Nyingchi region, which explained 37.9% of the total variance (p < 0.001). Our results suggest a high frequency and moderate amplitude variance of the relative humidity before 1800, and the variance reversed afterwards.
