Limited migration of soluble ionic species in a Siple Dome, Antarctica, ice core

Abstract

High-resolution (\u3e10 samples a−1) glaciochemical analyses covering the last 110 years from a Siplc Dome, Antarctica, ire core reveal limited migration of certain soluble ionic species (methane sulfonic acid, NO3 − and Mg2+). The observed chemical migration may be due in part to seasonal alternation between less acidic winter (from high sea-salt concentrations) and more acidic summer (from high marine biogenic acid concentrations) layers, common at coastal siles such as Siplc Dome. Exact mechanisms to expla in the migration are unclear, although simple diffusion and gravitational movement are unlikely since new peaks are formed where none previously existed in each case. Initial migration of each species is both shallower and earlier at Siple Dome than at other sites in Antarctica where similar phenomena have been observed, which may be related to the relatively low accumulation rate at Siple Dome (~13.3 cm ice a−1). Migration appears to be limited to either the preceding or following seasonal layer for each species, suggesting that paleoclimatic interpretations based on dala with lower than annual resolution are not likely to be affected