【摘要】 MGA雪芯是一支浅芯,长为27.05m。经雪层剖面与δ¹⁸O和电导率剖面相结合的综合对比分析,得到了该雪芯51a（1942～1992）的物质积累速率的时间序列。该序列的时间域分析结果表明,其采样点值为右偏正态分布,这一特征与青藏高原等地的冰芯分布特征相一致。其频率域分析结果表明,该处物质积累速率具有7a和3a的准周期变化。7a准周期与太阳活动的双振动周期很接近。从交叉谱分析看,该序列在3a准周期上与敦德冰芯的年物质积累速率序列相关较好。更多还原

【Abstract】 The length of MFA snow core is 27.50 m A 51-year time series of accumulation rate is obtained through the comprehensive analysis of the stratigraphy of snow core, stable isotopic ratio (δ18O)and electrical conductivity measurement (E.C>M).The analysis of time domain of the series indicates that the sampling values appear to be in a right-deviated normal distribution, which is in accordance with the results derived from the ice cores of Qing-Zang (Tibet) Plateau. The analysis of freqency domain of the series shows that there exist both 3-year and 7-year’s quasi-cycles of accumulation rate. The later is much close to solar double-fluctuation cycly, and the former shows a good correlation to the results of annual accumulation rate of the ice core from Dun-de Glacier, Qilian Mts., China.更多还原