Huang Wenyu, Wang Bin, Wright Jonathon S, Chen Ruyan
Ministry of Education Key Laboratory for Earth System Modeling, Center for Earth System Science, Tsinghua University, Beijing, China.
State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China.
PLoS One. 2016 Jun 30;11(6):e0158122. doi: 10.1371/journal.pone.0158122. eCollection 2016.
An area-weighted k-means clustering method based on pattern correlations is proposed and used to explore the relationship between the Siberian High (SH) and Arctic Oscillation (AO) during the winter months (December-January-February) of 1948-2014. Five regimes are identified. Four of these five regimes (comprising 171 of 201 months) show a negative correlation between the SH and AO indices, while the last regime (30 months) shows a positive correlation. The location of the SH shifts southward into China under two of the four negative-correlation regimes (117 months), with pressure variations over the center of activity for the SH opposite to pressure variations over the climatological center of the SH (which is used to define the SH index). Adjusting the SH index to account for these spatial shifts suggests positive rather than negative correlations between major variations in the SH and AO under these regimes. Under one of the two remaining negative-correlation regimes, pressure anomalies are weak over the Arctic Ocean. In total, only one regime comprising 21 of 201 months strictly obeys the negative correlation between the SH and AO reported by previous studies. The climate regime characterized by an intensified SH is associated with a greater frequency of cold surges over northern and southeastern China, and the weakening of the East Asian winter monsoon during the 1980s was accompanied by a sharp reduction in the occurrence of this regime.
提出了一种基于模式相关性的面积加权k均值聚类方法，并用于探究1948 - 2014年冬季月份（12月 - 1月 - 2月）西伯利亚高压（SH）与北极涛动（AO）之间的关系。识别出了五种气候态。这五种气候态中的四种（共201个月中的171个月）显示SH与AO指数呈负相关，而最后一种气候态（30个月）显示呈正相关。在四种负相关气候态中的两种（117个月）下，SH的位置向南移动到中国境内，SH活动中心的气压变化与用于定义SH指数的SH气候中心的气压变化相反。调整SH指数以考虑这些空间变化表明，在这些气候态下，SH和AO的主要变化之间呈正相关而非负相关。在剩下的两种负相关气候态中的一种下，北冰洋上的气压异常较弱。总体而言，在201个月中，只有一种包含21个月的气候态严格遵循先前研究报告的SH与AO之间的负相关关系。以增强的SH为特征的气候态与中国北方和东南部寒潮频率增加有关，20世纪80年代东亚冬季风减弱伴随着该气候态出现频率的急剧下降。
