The Recent Trend and Variance Increase of the Annular Mode
The Recent Trend and Variance Increase of the Annular Mode
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环形模的近期趋势和方差增加
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
S. Feldstein
中科院分区：
文献类型：
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作者：
S. Feldstein
本研究探讨了在过去的30年中，北方冬季环状模态的变化趋势和方差的增加是否来自大气内部变率。为了解决这个问题，合成的时间序列生成具有相同的季节内随机属性的环形模式。通过生成合成时间序列的线性趋势值的分布，并通过卡方统计分析，它表明，这种趋势和方差的增加远远超过了预期的水平，从内部变化的大气。这意味着环形模态的趋势和方差增加是由于与水圈和/或冰冻圈的耦合或气候系统外部的驱动。这种行为对比的前60年的20世纪，它表明，所有的年际变化的环形模式可以解释大气内部的变化。
This study examines whether both the trend and the increase in variance of the Northern Hemisphere winter annular mode during the past 30 years arise from atmospheric internal variability. To address this question, a synthetic time series is generated that has the same intraseasonal stochastic properties as the annular mode. By generating a distribution of linear trend values for the synthetic time series, and through a chi-square statistical analysis, it is shown that this trend and variance increase are well in excess of the level expected from internal variability of the atmosphere. This implies that both the trend and the variance increase of the annular mode are due either to coupling with the hydrosphere and/or cryosphere or to driving external to the climate system. This behavior contrasts that of the first 60 years of the twentieth century, for which it is shown that all of the interannual variability of the annular mode can be explained by atmospheric internal variability.