Reconstruction of Antarctic climate change using ice core proxy records from the coastal Dronning Maud Land, East Antarctica
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- Thamban, M., Laluraj, C.M., Naik, S.S. et al. J Geol Soc India (2011) 78: 19. doi:10.1007/s12594-011-0063-y
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Antarctic ice core records have provided unprecedented information on past climatic changes and forcing factors on decadal to millennial timescales. The glaciochemical and stable isotope records of a shallow ice core from the coastal Dronning Maud Land (East Antarctica) were used here to reconstruct the coastal Antarctic environmental variability during the past ∼470 years. Sea salt ion data indicate a significant additional contribution of chloride ions compared to sea water values, possibly through atmospheric scavenging. The nitrate (NO3−) profile exhibit significant temporal shifts than that of the sulphate (SO42−), with a major shift around 1750 AD. The changes in NO3− record are synchronous with the proxy record of solar activity (10Be profile from a South Pole ice core), suggesting enhanced NO3− values during periods of reduced solar activity like the Dalton Minimum (∼1790–1830 AD) and Maunder Minimum (∼1640–1710 AD). The δ18O records reveal that the more negative δ18O values were coeval with several events of increased NO3− concentrations, suggesting enhanced preservation of NO3− during periods of reduced air temperatures. The δ18O and δD records of the core also suggest significant short-term and long-tem variability with more negative values indicating relatively lower air temperatures prior to 1715 AD. The δ18O records also revealed a significant warming of 2.7°C for the past 470 years, with a warming of ∼0.6°C per century.