Snow Chemistry Across Antarctica

An updated compilation of published and new data of major-ion (Ca, Cl, K, Mg, Na, NO3, SO4) and methylsulfonate (MS) concentrations in snow from 520 Antarctic sites is provided by the national ITASE (International Trans-Antarctic Scientific Expedition) programmes of Australia, Brazil, China, Germany, Italy, Japan, Korea, New Zealand, Norway, the United Kingdom, the United States and the national Antarctic programme of Finland. The comparison shows that snow chemistry concentrations vary by up to four orders of magnitude across Antarctica and exhibit distinct geographical patterns. The Antarctic-wide comparison of glaciochemical records provides a unique opportunity to improve our understanding of the fundamental factors that ultimately control the chemistry of snow or ice samples. This paper aims to initiate data compilation and administration in order to provide a framework for facilitation of Antarctic-wide snow chemistry discussions across all ITASE nations and other contributing groups. The data are made available through the ITASE web page (http:// www2.umaine.edu/itase/content/syngroups/snowchem.html) and will be updated with new data as they are provided. In addition, recommendations for future research efforts are summarized

Spatio-temporal variability in volcanic sulphate deposition over the past 2 kyr in snow pits and firn cores from Amundsenisen, Dronning Maud Land, Antarctica

In the framework of the European Project for Ice Coring in Antarctica (EPICA), a comprehensive glaciological pre-site survey has been carried out on Amundsenisen, Dronning Maud Land, East Antarctica, in the past decade. Within this survey four intermediate-depth ice cores and 13 snow pits were analysed for their ionic composition and interpreted with respect to the spatial and temporal variability of volcanic sulphate deposition. The comparison of the non-sea-salt (nss)-sulphate peaks that are related to the well-known eruptions of Mt. Pinatubo and Cerro Hudson in AD 1991 revealed sulphate depositions of comparable size (15.8±3.4 kg km-2) in 11 snow pits. There is a tendency to higher annual concentrations for smaller snow accumulation rates. The combination of seasonal sodium and annually resolved nss-sulphate records allowed the establishment of a time-scale derived by annual layer counting over the last 2000 years and thus a detailed chronology of annual volcanic sulphate deposition. Using a robust outlier detection algorithm, 49 volcanic eruptions were identified between AD 165 and 1997. The dating uncertainty is ±3 years between AD 1997 and 1601, around ±5 years between AD 1601 and 1258, and increasing to ±24 years at AD 165, improving the accuracy of the volcanic chronology during the penultimate millenium considerably

Influence of large-scale teleconnection patterns on methane sulfonate ice core records in Dronning Maud Land

Records of methane sulfonate (MS) in ice cores from the high plateau of DronningMaud Land (DML), Antarctica, drilled in the framework of the European Project for IceCoring in Antarctica, are investigated for their potential as an environmental andclimate archive for the Atlantic sector of the Southern Ocean. Despite postdepositionalchanges, years of extraordinary MS concentrations can be clearly detected in the icecore records. We use composite anomaly maps of atmospheric parameters from theNational Centers for Environmental Prediction/National Center for Atmospheric Researchreanalysis fields for years of extreme MS concentration to detect atmospheric patternscausing MS variability. Changing atmospheric transport is shown to be an important,but not exclusive, parameter being conserved in the MS record in DML. The oftenhypothesized direct link between high MS concentrations and El Nino events is notsupported for the observed region whereas the Antarctic Dipole (ADP), which ismodulated by El Nino Southern Oscillation conditions, exerts significant influence. Aclear 13.9-year cycle can be found throughout a 2000-year MS record that can be relatedto variations in the ADP. Over the last 300 years a 4.6-year cycle is revealed in theMS (and sea-salt record), which vanishes in the deeper part of the ice core as aconsequence of diffusion processes. From the long-term perspective, periods of high MSconcentrations are connected to, on average, higher sea-salt aerosol as well, reflecting aseasonally independent influence of transport on both species. A distinctive period ofefficient atmospheric transport, probably due to a pronounced ADP, could be foundfrom 1200 to 1600 A.D

Snow chemistry across Antarctica

Un updated compilation of published and new data of major ion (Ca, Cl, K, Mg, Na, NO3, SO4) and methylsulfonate (MS) concentrations in snow from 520 Antarctic sites is provided by the national ITASE (International Trans-Antarctic Scientific Expedition) programmes of Australia, Brazil, China, Germany, Italy, Japan, Korea, New Zealand, Norway, United Kingdom, the United States, and the national Antarctic programme of Finland. The comparison shows that snow chemistry concentrations vary by up to four orders of magnitude across Antarctica and exhibit distinct geographical patterns. The Antarctic-wide comparison of glaciochemical records provides a unique opportunity to improve our understanding of the fundamental factors that ultimately control the chemistry of snow or ice samples. This paper aims to initiate data compilation and administration in order to provide a framework for facilitation of antarctic-wide snow chemistry discussions across all ITASE nations and other contributing groups. The data are made available through the ITASE web page (http://www2.umaine.edu/itase/content/syngroups/snowchem.html) and will be updated with new data as they are provided. In addition, recommendations for future research efforts are summarized

Snow chemistry across Antarctica

An updated compilation of published and new data of major-ion (Ca, Cl, K, Mg, Na, NO3, SO4) and methylsulfonate (MS) concentrations in snow from 520 Antarctic sites is provided by the national ITASE (International Trans-Antarctic Scientific Expedition) programmes of Australia, Brazil, China, Germany, Italy, Japan, Korea, New Zealand, Norway, the United Kingdom, the United States and the national Antarctic programme of Finland. The comparison shows that snow chemistry concentrations vary by up to four orders of magnitude across Antarctica and exhibit distinct geographical patterns. The Antarctic-wide comparison of glaciochemical records provides a unique opportunity to improve our understanding of the fundamental factors that ultimately control the chemistry of snow or ice samples. This paper aims to initiate data compilation and administration in order to provide a framework for facilitation of Antarctic-wide snow chemistry discussions across all ITASE nations and other contributing groups. The data are made available through the ITASE web page (http://www2.umaine.edu/itase/content/syngroups/snowchem.html) and will be updated with new data as they are provided. In addition, recommendations for future research efforts are summarized