Abstract
High-resolution records of nitrate (NO3 −), oxygen isotope (δ 18O) and non-sea salt sulphate (nssSO4 2− ) were studied using an ice core collected from central Dronning Maud Land in East Antarctica to identify the influence of environmental variability on accumulation of NO3 − over the past 450 years. The results confirmed that multiple processes were responsible for the production and preservation of NO3 − in Antarctic ice. Correlation between NO3 − and nssSO4 2− peaks revealed that sulphate aerosols released during major volcanic eruptions might have activated the production of nitric acid, which was scavenged by ion-induced nucleation in polar ice sheets. The correlation between the nitrate and δ18 O records further suggest that enhanced NO3 − preservation in the ice occurred during periods of lower atmospheric temperature. Major shifts in the NO3 − record of the ice core presently studied and its comparison with 10Be record from a core collected from South Pole suggest that a reduction in solar activity influenced the NO3 − accumulation in Antarctica through enhanced production of odd nitrogen species.
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