Abstract. Paleoclimate archives, such as high-resolution ice core records, provide a means to investigate long-term (multi-centennial) climate variability. Until recently, the Law Dome (Dome Summit South) ice core record remained one of few long-term high-resolution records in East Antarctica. A new ice core drilled in 2017/2018 at Mount Brown South, approximately 1000 km west of Law Dome, provides an additional high-resolution record that will likely span the last millennium in the Indian Ocean sector of East Antarctica. Here, we compare snowfall accumulation rates and sea salt concentrations in the upper portion (~21 m) of the Mount Brown South record, and an updated Law Dome record over the period 1975–2016. Annual sea salt concentrations from the Mount Brown South record preserves a stronger signal for the El Niño-Southern Oscillation (ENSO; in austral winter and spring, r = 0.521, p r = −0.387, p = 0.018, Niño 3.4). The Mount Brown South and Law Dome ice cores record inverse signals for the ENSO, suggesting the occurrence of distinct moisture and aerosol intrusions. We suggest that ENSO-related sea surface temperature anomalies in the equatorial Pacific drive atmospheric teleconnections in the southern mid-latitudes. These anomalies are associated with a weakening (strengthening) of regional westerly winds to the north of Mount Brown South that corresponds to years of low (high) sea salt deposition at Mount Brown South during La Niña (El Niño) events. The Mount Brown South annual sea salt record when complete will offer a new proxy record for reconstructions of the ENSO over the recent millennium, along with improved understanding of regional atmospheric variability in the southern Indian Ocean in addition to that derived from Law Dome.

中文翻译：

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新南极东部冰芯南布朗山的厄尔尼诺南部涛动信号

摘要。古气候档案，例如高分辨率的冰芯记录，提供了调查长期（几百年）气候变异性的手段。直到最近，Law Dome（Dome峰会南部）冰芯记录仍是南极东部地区为数不多的长期高分辨率记录之一。2017/2018年，在Law Dome以西约1000公里处的布朗山南（South Brown South）钻了一个新的冰芯，该冰芯提供了额外的高分辨率记录，该记录可能跨越南极东部印度洋海域的最后一个千年。在这里，我们比较了南布朗山记录的上部（约21 m）的降雪累积率和海盐浓度，以及1975-2016年期间更新的Law Dome记录。来自南布朗山记录的年度海盐浓度为厄尔尼诺-南方涛动（ENSO;r  = 0.521，P  r = -0.387，P = 0.018，尼诺3.4）。南布朗山冰山和Law Dome冰芯记录了ENSO的反信号，表明发生了明显的湿气和气溶胶侵入。我们建议，赤道太平洋与ENSO有关的海面温度异常会推动中南纬度地区的大气遥相关。这些异常与布朗山南部以北的区域性西风减弱（变强）有关，这对应于拉尼娜（厄尔尼诺）事件期间布朗山南部低（高）海盐沉积的年份。完成后的南布朗山年度海盐记录将为近千年来的ENSO重建提供新的代理记录，并进一步了解印度洋南部的区域大气变异性，以及从劳顿穹顶得到的信息。