The Antarctic stratospheric polar vortex (SPV) is a crucial feature of the stratospheric system in winter. The variation in the strength of the Antarctic SPV significantly impacts the weather and climate of the Southern Hemisphere (SH). Although previous studies have provided a good understanding of the variations in the strength of the Antarctic SPV and its associated physical mechanisms, the trend of the Antarctic SPV after 2000 has not received sufficient attention. Here, based on observations and reanalysis data, we find that the middle SPV has a strengthening trend in austral winter during 2000–2022. Our findings indicate that warming SST alter atmospheric convection and planetary wave activity, reducing wavenumber-1 planetary waves into the stratosphere and thereby strengthening the polar vortex. Using idealized sea surface temperature (SST) patch experiments with a climate model, we quantified the specific contributions of SST warming in various regions. Among these, the tropical Atlantic, North Indian Ocean, West Pacific warm pool, and East Pacific contributed 106.86 %, −52.67 %, −40.72 %, and 36.94 %, respectively, to the cooling of the polar vortex from 2000 to 2022. On decadal timescales, the variability of tropical SST patterns, particularly in the Atlantic and Pacific basins, has been critical in shaping the observed trends and fluctuations in the Antarctic SPV during recent decades.

中文翻译：

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南极冬季南极平流层涡旋增强：区域海面温度的贡献


南极平流层极地涡旋 （SPV） 是冬季平流层系统的一个重要特征。南极 SPV 强度的变化对南半球 （SH） 的天气和气候有重大影响。尽管以前的研究对南极 SPV 强度的变化及其相关的物理机制提供了很好的理解，但 2000 年后南极 SPV 的趋势并未得到足够的重视。在这里，基于观测和再分析数据，我们发现 2000—2022 年南方冬季中期 SPV 呈增强趋势。我们的研究结果表明，变暖的海温改变了大气对流和行星波活动，减少了进入平流层的 1 号行星波，从而加强了极地涡旋。使用气候模型的理想化海面温度 （SST） 斑块实验，我们量化了 SST 变暖在各个地区的具体贡献。其中，2000—2022 年热带大西洋、北印度洋、西太平洋暖池和东太平洋对极涡冷却的贡献率分别为 106.86 %、−52.67 %、−40.72 % 和 36.94 %。在年代际时间尺度上，热带海温型的变化，特别是在大西洋和太平洋盆地，对于塑造近几十年来观测到的南极 SPV 的趋势和波动至关重要。