The study examines the influence of external climate forcings, and atmosphere–ocean–sea–ice coupled interaction on the Southern Hemisphere (SH) atmospheric circulation variability. We analysed observed and simulated changes in view of Antarctic sea–ice and Southern Ocean surface temperature trends over recent decades. The experiment embraces both idealised and comprehensive methods that involves an Earth System Model (ESM) prototype. The sensitivity experiment is conducted in a manner that decomposes the signatures of sea–ice, sea surface temperature and feedback mechanisms. The results reveal that the Southern Annular Mode (SAM) multidecadal variability is found to be modulated by coupled interactions whereas its sub-seasonal to interannual vacillation seems to follow a random trajectory. The latter may strengthen the notion that its predictability is limited even with the use of ESMs. Most of the atmospheric circulation variability and recent changes may be explained by the ocean thermal forcing and coupled interactions. However, the influence of sea–ice forcing alone is largely indistinguishable and predominantly localised in nature. The result also confirms that the Antarctic dipole-like sea–ice pattern, a leading climate mode in the SH, has intensified in the last three decades irrespective of season. The probable indication is that processes within the Southern Ocean may play a key role, which deserves further investigation.

该研究考察了外部气候强迫以及大气-海洋-海冰耦合相互作用对南半球（SH）大气环流变化的影响。我们分析了近几十年来南极海冰和南大洋表面温度趋势的观测和模拟变化。实验包含涉及地球系统模型（ESM）原型的理想方法和综合方法。进行敏感性实验的方式可以分解海冰的特征，海面温度和反馈机制。结果表明，南部环形模式（SAM）的年代际变化被发现是由耦合相互作用调节的，而其亚季节到年际波动似乎遵循随机轨迹。后者可能会强化这样的观念：即使使用ESM，其可预测性也受到限制。大部分的大气环流变化和最近的变化可以用海洋热强迫和耦合作用来解释。但是，仅靠海冰强迫的影响在本质上几乎是无法区分的，并且主要局限在自然界中。结果还证实，南极偶极状海冰模式是南半球的主要气候模式，在过去的三十年中，无论季节如何，这种模式都在加剧。可能的迹象是，南大洋内部的过程可能起着关键作用，值得进一步研究。单独受海冰强迫的影响在本质上几乎是无法区分的，并且主要局限于本地。结果还证实，南极偶极状海冰模式是南半球的主要气候模式，在过去的三十年中，无论季节如何，这种模式都在加剧。可能的迹象是，南大洋内部的过程可能起着关键作用，值得进一步研究。单独受海冰强迫的影响在本质上几乎是无法区分的，并且主要局限于本地。结果还证实，南极偶极状海冰模式是南半球的主要气候模式，在过去的三十年中，无论季节如何，这种模式都在加剧。可能的迹象是，南大洋内部的过程可能起着关键作用，值得进一步研究。