A database of surface Antarctic snow isotopic composition is constructed using available measurements, with an estimate of data quality and local variability. Although more than 1000 locations are documented, the spatial coverage remains uneven with a majority of sites located in specific areas of East Antarctica. The database is used to analyze the spatial variations in snow isotopic composition with respect to geographical characteristics (elevation, distance to the coast) and climatic features (temperature, accumulation) and with a focus on deuterium excess. The capacity of theoretical isotopic, regional, and general circulation atmospheric models (including "isotopic" models) to reproduce the observed features and assess the role of moisture advection in spatial deuterium excess fluctuations is analyzed.
ABSTRACT. An updated compilation of published and new data of major-ion (Ca, Cl, K, Mg, Na, NO 3 , SO 4 ) 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.
Abstract. The Mount Johns (MJ) ice core (79°55′ S; 94°23′ W) was drilled near the Pine Island Glacier ice divide on the West Antarctic Ice Sheet during the 2008–2009 austral summer, to a depth of 92.26 m. The upper 45 m of the record covers approximately 125 years (1883–2008), showing marked seasonal variability. Trace element concentrations in 2137 samples were determined using inductively coupled plasma mass spectrometry. In this study, we reconstruct mineral dust and sea salt aerosol transport and investigate the influence of climate variables on the elemental concentrations at the MJ site. The ice core record reflects changes in emissions as well as atmospheric circulation and transport processes. Our trajectory analysis shows distinct seasonality, with strong westerly transport in the winter months and secondary northeasterly transport in the summer. During summer months, the trajectories present slow-moving (short) transport and are more locally influenced than in other seasons. Finally, our reanalysis correlations with trace element suggest that marine-derived trace element concentrations are strongly influenced by sea ice concentration and sea surface temperature anomalies. The results show that seasonal elemental concentration maxima in sea salt elements correlate well with the sea ice concentration winter maxima in the west Amundsen and Ross seas. Lastly, we observed an increased concentration of marine aerosols when sea surface temperature decreased.
An ice core, 92.26 m in length, was collected near the ice divide of the West Antarctica ice sheet during the 2008/2009 austral summer. This paper described the fieldwork at the Mount Johns site (79º55'S; 94º23'W) and presented the first results of the upper 45.00 m record covering approximately 125 years (1883 -2008), dated by annual layer counting and volcanic reference horizons. Trace element concentrations in 2,137 samples were determined using inductively coupled plasma mass spectrometry. The concentrations obtained for Al, Ba, Ca, Fe, K, Mg, Mn, Na, Sr and Ti are controlled by climate variations, the transport distance, and the natural sources of these aerosols. Natural dust contributions, mainly derived from the arid areas of Patagonia and Australia, are important sources for aluminum, barium, iron, manganese and titanium. Marine aerosols from sea ice and transported by air masses are important sources of sodium and magnesium. Calcium, potassium and strontium showed considerable inputs of both continental dust and marine aerosols. KEYWORDS:Trace elements; Ice core; West Antarctica ice sheet; ICP-SFMS. RESUMO: Um testemunho de neve de 92,26 m foi coletado em um dos divisores da bacia de drenagem glacial do manto de gelo da Antártica Ocidental no verão austral de 2008/2009. Este artigo descreveu os trabalhos de campo no sítio Mount Johns (79º55'S; 94º23'W) e apresentou os resultados das análises dos 45,00 m do registro superiores do testemunho e que representam cerca de 125 anos (1883 -2008) de precipitação de neve, datados por meio da contagem anual das camadas e dos horizontes vulcânicos de referência. Os elementos-traço estudados neste trabalho foram determinados usando espectrometria
Purpose The purpose of this paper is to develop a conceptual framework that incorporates factors external to the organization into the business process management (BPM) lifecycle through dynamic capabilities (DCs), beginning with strategy and persisting through the business process transformation. Design/methodology/approach The study comprised four distinct phases. First, a literature review was conducted to identify validated theoretical models related to the topic. Then, a systematic review of the literature was conducted by accessing the EBSCOhost, ISI/Web of Science and Scopus databases, for the purpose of understanding how the relationship between BPM and DCs has been addressed. The third step was the identification of the meta-capabilities involved in the relationship between DC and BPM, the fourth step was the construction of a framework that integrated an external view into BPM through DC, and the final step evaluated these framework through a case study. Findings Ten texts were selected after a systematic literature review. The following main points of convergence were identified: DC contributes to the conceptualization and understanding of BPM, DC assists in the process of organizational change by promoting the adaptation of the company to the environment, and DC enhances BPM performance. A framework was developed and presented. Practical implications The proposed framework, which incorporates an external perspective into the BPM lifecycle through DCs, can be used by managers and researchers interested in the promotion of BPM. Originality/value The study shows how the sensing, seizing and transforming meta-capabilities can act to evaluate the outside-in perspective, serve as a benchmark for the alignment of business processes and enable the operationalization of emerging demands through the dynamic adaptation of processes.
This study presents the ion chromatography analysis of an Antarctic ice core (IC-3; 85°59'S, 81°35'W) and discusses Mg , Na + and Cl -concentration peaks, are environmentally interpreted as winter layers and lower concentrations are considered as summer ones and can be directly associated to sea spray. The higher concentrations in winter are probably caused by transport of marine air masses over the Antarctic ice sheet, which are stronger in this season. There are probably additional sources for Cl − in the IC-3 core region, which could have originated from gaseous HCl adsorption processes, essentially as a result of acid-base reactions between NaCl and HNO 3 or H 2 SO 4 in aerosol particles or directly over the snow surface. Key-words: glaciochemistry, ice core, ion chromatography. Resumo Este artigo apresenta resultados da análise por cromatografia iônica, de um testemunho de gelo antártico (IC-3; 85° 59'S, 81° 35'W) e discute os dados de concentração dos íons
Abstract. The Mount Johns (MJ) ice core (79º55' S; 94º23' W) was drilled near the Pine Island Glacier ice divide on the West Antarctic Ice Sheet during the 2008–2009 austral summer, to a depth of 92.26 m. The upper 45 m of the record covers approximately 125 years (1883–2008) showing marked seasonal variability. Trace element concentrations in 2,137 samples were determined using inductively coupled plasma mass spectrometry. In this study, we reconstruct mineral dust and sea salt aerosol transport and investigate the influence of climate variables on the elemental concentrations to the MJ site. The ice core record reflects changes in emissions as well as atmospheric circulation and transport processes. Our trajectory analysis shows distinct seasonality, with strong westerly transport in the winter months and a secondary northeasterly transport in the summer. During summer months, the trajectories present slow-moving (short) transport and are more locally influenced than in other seasons. Finally, our reanalysis trace element correlations suggest that marine derived trace element concentrations are strongly influenced by sea ice concentration and sea surface temperature anomalies. The results show that seasonal elemental concentration maxima in sea-salt elements correlate well with the sea ice concentration winter maxima in the West Amundsen and Ross Seas. Lastly, we observed an increased concentration of marine aerosols when sea surface temperature decreased.
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