Nitrate records of a shallow ice core from East Antarctica: Atmospheric processes, preservation and climatic implications

• Published in: The Holocene
• Main Authors: Laluraj, C.M., Thamban, M., Naik, S.S., Redkar, B.L., Chaturvedi, A., Ravindra, R.
• Format: Article in Journal/Newspaper
• Language: English
• Published: SAGE Publications 2010
• Subjects: Paleontology; Earth-Surface Processes; Ecology; Archeology; Global and Planetary Change; Antarctic; Dronning Maud Land; East Antarctica; South Pole; Antarc*; Antarctica; ice core; South pole
• Online Access: http://dx.doi.org/10.1177/0959683610374886; http://journals.sagepub.com/doi/pdf/10.1177/0959683610374886

High-resolution records of nitrate (NO 3 − ), oxygen isotope (δ 18 O) and non-sea salt sulphate (nssSO 4 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 NO 3 − over the past 450 years. The results confirmed that multiple processes were responsible for the production and preservation of NO 3 − in Antarctic ice. Correlation between NO 3 − and nssSO 4 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 δ 18 O records further suggest that enhanced NO 3 − preservation in the ice occurred during periods of lower atmospheric temperature. Major shifts in the NO 3 − record of the ice core presently studied and its comparison with 10 Be record from a core collected from South Pole suggest that a reduction in solar activity influenced the NO 3 − accumulation in Antarctica through enhanced production of odd nitrogen species.