Antarctic station‐based seasonal pressure reconstructions since 1905: 2. Variability and trends during the twentieth century
Antarctic station‐based seasonal pressure reconstructions since 1905: 2. Variability and trends during the twentieth century
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DOI：
10.1002/2015jd024565
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发表时间：
2016-03
期刊：
影响因子：
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通讯作者：
R. Fogt;Julie M. Jones;Chad A. Goergens;Megan E. Jones;G. A. Witte;Ming Yueng Lee
中科院分区：
文献类型：
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作者：
R. Fogt;Julie M. Jones;Chad A. Goergens;Megan E. Jones;G. A. Witte;Ming Yueng Lee
在我们的同伴论文中评估的南极季节性基于站的压力重建在这里进行评估，以提供关于二十世纪南极压力变化的额外知识。在1905年至1956年期间，我们发现哈德利中心网格海平面气压数据集与我们的重建相比最好，这可能是由于类似的方法来估计压力而无需直接观测。对二十世纪世纪南极压力变化的主要关注点是夏季和冬季，因为这两个季节的重建技术最高。在夏季，有相当大的年际变化，在整个南极洲的空间均匀。在1911/1912年和1925/1926年的夏季发现了显著的高压异常，这两个夏季都对应着南半球环状模的负位相以及热带太平洋的厄尔尼诺事件。此外，在整个南极洲过去40年的负夏季压力趋势在整个20世纪的30年趋势的背景下是独特的，这表明最近的夏季趋势中有很强的人为强迫成分。相比之下，平均冬季压力是较少的变化，每年在世纪初，有较少的相似性之间的压力变化沿着南极半岛相比，其余的大陆。在整个南极洲没有发现明显的气压趋势（尽管可以确定一些重要的区域趋势），低频，多年尺度的变化似乎主导了这个季节的历史气压变化。
The Antarctic seasonal station‐based pressure reconstructions evaluated in our companion paper are evaluated here to provide additional knowledge on Antarctic pressure variability during the twentieth century. In the period from 1905 to 1956, we find that the Hadley Centre gridded sea level pressure data set compared the best with our reconstructions, perhaps due to similar methods to estimate pressure without direct observations. The primary focus on the twentieth century Antarctic pressure variability was in summer and winter, as these were the seasons with the highest reconstruction skill. In summer, there is considerable interannual variability that was spatially uniform across all of Antarctica. Notable high pressure anomalies were found in the summers of 1911/1912 and 1925/1926; both summers correspond to negative phases of the Southern Annular Mode as well as El Niño events in the tropical Pacific. In addition, negative summer pressure trends during the last ~40 years across all of Antarctica are unique in the context of 30 year trends throughout the entire twentieth century, suggesting a strong component of anthropogenic forcing on the recent summer trends. In contrast, mean winter pressure is less variable from year to year during the early twentieth century, and there is less similarity between the pressure variations along the Antarctic Peninsula compared to the rest of the continent. No significant pressure trends were found consistently across all Antarctica (although some significant regional trends can be identified), and low‐frequency, multidecadal‐scale variability appears to dominate the historical pressure variations in this season.