Sea salt species in firn cores drilled at Styx Glacier, Northern Victoria Land, Antarctica, as a proxy for past variability in large-scale atmospheric circulation

초록

Atmospheric circulation patterns such as Amundsen Sea Low (ASL) play a pivotal role in climate system of the Antarctic and thereby global climate system. To understand and reconstruct past variations of such atmospheric patterns, changes in chemical compositions from sea salt and biogenic aerosols in Antarctic snow and ice cores have been generally utilized. In this study, we investigated the potential of variations in sea salt species and biogenic sulfur in firn/ice cores from Styx Glacier, northern Victoria Land, East Antarctica, as proxy records for reconstructing atmospheric circulation in the Southern Hemisphere. The sea spray composition presents strong positive correlation with the winter ASL center pressure. When the ASL is deepened, southern and southwestern winds would increase, obstructing arrival of air masses to Styx Glacier from the Ross Sea, which is the plausible origin of the sea salt aerosol. In contrast, the biogenic sulfur is not related to the meteorological condition, but rather linked to spatial changes in the Ross Sea and Terra Nova Bay polynyas. Accordingly, our study suggests that sea spray record of the Styx cores can be used as highly resolved proxy record to reconstruct the past variation in the ASL for a longer period of times.