Centennial-Scale Variability in Atmospheric Circulation in Antarctica: Insights From a Coastal East Antarctic Ice Core Record

文献类型： 外文期刊

第一作者： Li, Zhe

作者： Li, Zhe;Shi, Guitao;Wang, Danhe;Zhang, Bo;Li, Zhe;Shi, Guitao;Wang, Danhe;Zhang, Bo;Li, Zhe;Jiang, Su;Ma, Tianming;Yu, Jinhai;Guo, Jingxue;Shi, Guitao;Wang, Danhe;Ma, Tianming;Yu, Jinhai

作者机构：

关键词： Antarctica; ice core; atmospheric circulation

期刊名称：JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES （ 影响因子：3.4； 五年影响因子：4.4 ）

ISSN： 2169-897X

年卷期： 2025 年 130 卷 7 期

页码：

收录情况： SCI

摘要： A 108-m ice core (32SC) spanning the period from 1616 to 2016 CE was retrieved from coastal Princess Elizabeth Land (PEL), East Antarctica (69.97 degrees S, 76.52 degrees E, 1,113 m elevation). The ice core was analyzed to investigate the relationship between sea salt aerosols (SSAs), sea ice dynamics, and atmospheric circulation. The first component of Empirical Orthogonal Function analysis (32SC REOF1), which explains 58% of the variance in the ice core ions, serves as a proxy for SSAs. Time series correlation analysis reveals that sea ice had a minimal impact on 32SC REOF1. Instead, it showed a significant correlation with winter meridional atmospheric transport from the Southern Indian Ocean to PEL. The sea salt records exhibit a significant increase from the period 1616-1850 to 1851-2016 CE, with the mean value increasing by a factor of 2.4. This centennial-scale trend is likely linked to shifts in the position of the Southern Hemisphere Westerly Winds (SHWW). During the earlier period (1616-1850 CE), which was likely characterized by a colder climate, the SHWW in the Southern Indian Ocean sector may have shifted equatorward and weakened in intensity, potentially leading to reduced cyclone frequency and a subsequent decline in SSAs transport to high latitudes. In contrast, the period 1851-2016 CE, which is likely warmer, saw the SHWW shifted poleward, enhancing meridional wind speeds and increasing SSAs transport. Comparisons with other Antarctic ice core records suggest that the centennial-scale shift in the SHWW is a regional phenomenon, particularly pronounced in the Southern Indian Ocean. Plain Language Summary Ice core records play a crucial role in understanding the past changes in climate; specifically, sea salts in ice cores can provide insights into the extent of sea ice and/or the strength of atmospheric transport. However, interpreting sea salts as a climate proxy can vary by region. In this study, we present a sea salt record from an ice core drilled in coastal Princess Elizabeth Land, East Antarctica. We observed significant differences in sea salt concentrations between the periods 1616-1850 CE and 1851-2016 CE, suggesting a shift in climate conditions. These changes are likely linked to shifts in the latitudinal position of the Southern Hemisphere Westerly Winds (SHWW) belt, which have influenced the strength of meridional atmospheric transport of sea salts. The temporal patterns of sea salts in the ice core indicate a significant centennial-scale shift in the SHWW over the Southern Indian Ocean sector, with an increase in sea salts transport after 1850 CE. This finding provides valuable insights into the centennial timescale migration of the SHWW and its implications for climate change.

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