The anticyclonic high-pressure systems over the southern-hemisphere, subtropical oceans have a significant influence on regional climate. Previous studies of how these subtropical anticyclones will change under global warming have focused on austral summer while the winter season has remained largely uninvestigated, together with the extent to which the dominant mechanisms proposed to explain the multi-model-mean changes similarly explain the inter-model spread in projections. This study addresses these gaps by focusing on the mechanisms that drive the spread in projected future changes across the Coupled Model Intercomparison Project Phase 5 and 6 archives during both the summer and winter seasons. The southern hemisphere anticyclones intensify in strength at their center and poleward flank during both seasons in the future projections analyzed. The inter-model spread in projected local diabatic heating changes accounts for a considerable amount of the inter-model spread in the response of the South Pacific anticyclone during both seasons. However, model differences in projected zonal-mean tropospheric static stability changes, which in turn influence baroclinic eddy growth, are most influential in determining the often-strong increases in sea level pressure seen along the poleward flank of all the anticyclones during both seasons. Increased zonal-mean tropospheric static stability over the subtropics is consistent with the poleward shift in Hadley cell edge and zonal-mean sea level pressure increases. The results suggest that differences in the extent of tropical-upper-tropospheric and subtropical-lower-tropospheric warming in the southern hemisphere, via their influence on tropospheric static stability, will largely determine the fate of the anticyclones over the coming century.

南半球，亚热带海洋上的反气旋高压系统对区域气候有重大影响。先前关于这些亚热带反气旋在全球变暖下将如何变化的研究主要集中在南方夏季，而冬季尚未得到充分研究，以及解释多模式均值变化的主导机制在多大程度上类似地解释了相互影响。模型分布在投影中。这项研究着眼于这些机制，着重研究了在夏季和冬季，耦合模型间比较项目第5和第6阶段档案的预期未来变化传播的机制。在分析的未来预测中，在两个季节中，南半球反气旋的强度在中央和极向两侧增强。预计的局部非绝热加热变化的模型间扩散占两个季节南太平洋反气旋响应的模型间扩散的很大一部分。但是，预测的纬向平均对流层静态稳定性变化的模型差异反过来又影响斜压涡流的增长，在确定两个季节中沿所有反气旋极极侧面经常出现的海平面压力的强烈增加时，影响最大。在亚热带，纬向平均对流层静态稳定性的增加与哈德利单元边缘的极移有关，纬向平均海平面压力升高。结果表明，南半球热带对流层上方和副热带对流层下方变暖程度的差异，