摘要
A continuous record of surface temperature for the past 2650 years was obtained in an earlier study from a Beijing stalagmite based on sedimentary layer counting and thickness measurements.Singular spectrum analysis,multi-taper and wavelet spectral analyses are used in this study to identify decadal-scale signals and their origins in this record.Besides long-term cycles of solar origin identified in earlier studies,this record contains cycles that dominate temperature with periods of 102-70,66-50,31,25-22,19,15,12 and 9 years.The 102-70,25-22,12 and 9 year cycles are attributable to solar variation,while the others are likely to be related to low-latitude ocean forcing.These results suggest that century-scale changes in the Beijing summer temperature over the past 2650 years are primarily controlled by solar variation,while ocean-atmospheric interactions play a prominent role in modu-lating decadal-scale variability.
A continuous record of surface temperature for the past 2650 years was obtained in an earlier study from a Beijing stalagmite based on sedimentary layer counting and thickness measurements. Singular spectrum analysis, multi-taper and wavelet spectral analyses are used in this study to identify decadal-scale signals and their origins in this record. Besides long-term cycles of solar origin identified in earlier studies, this record contains cycles that dominate temperature with periods of 102-70, 66-50, 31, 25-22, 19, 15, 12 and 9 years. The 102-70, 25-22, 12 and 9 year cycles are attributable to solar variation, while the others are likely to be related to low-latitude ocean forcing. These results suggest that century-scale changes in the Beijing summer temperature over the past 2650 years are primarily controlled by solar variation, while ocean-atmospheric interactions play a prominent role in modulating decadal-scale variability.
基金
supported by the National Basic Research Program of China(2010CB950200)
关键词
年代际
北京
变异
气温
季节
温暖
表面温度
太阳变化
stalagmite, singular spectrum analysis (SSA), decadal climate cycles, warm season temperature