El Niño–Southern Oscillation signal in a new East Antarctic ice core, Mount Brown South

Abstract. Paleoclimate archives, such as high-resolution ice core records, provide a means to investigate past climate variability. Until recently, the Law Dome (Dome Summit South site) record remained one of few millennial-length coastal records in East Antarctica. A new drilled 2017/2018 at Mount Brown South, approximately 1000 km west Dome, provides an additional that will likely span last millennium Indian Ocean sector Here, we compare snow accumulation rates and sea salt concentrations upper portion (∼ 20 m) three cores updated over period 1975–2016. Annual from site preserve stronger signal for El Niño–Southern Oscillation (ENSO; austral winter spring, r = 0.533, p < 0.001, Multivariate Niño Index) compared previously defined summer (November–February, 0.398, 0.010, Southern Index). The inverse signals ENSO, possibly due longitudinal variability meridional transport southern Ocean, although further analysis is needed confirm this. We suggest ENSO-related surface temperature anomalies equatorial Pacific drive atmospheric teleconnections mid-latitudes. These are associated with weakening (strengthening) regional westerly winds north correspond years low (high) deposition during La Niña (El Niño) events. extended annual (when complete) may offer proxy reconstructions ENSO recent millennium, along improved understanding addition derived Dome.