Continental dust impurities in Antarctic ice provide information on climate changes in the dust source areas and on past atmospheric circulation. We investigated records of dust species from the last 45 ka in the East Antarctic EPICA DomeC (EDC) ice core with special emphasis on the lithium (Li) content of dust. We obtained two complementary Li-records using a new Ion Chromatography (IC) technique in line with Inductively Coupled Plasma-Sector Field Mass Spectroscopy (ICP-SFMS). Concentrations of soluble Li (Li+) were obtained using IC, while total concentrations of Li (LiT) were obtained using ICP-SFMS, providing an ideal opportunity to investigate the soluble and insoluble chemistry of Li in East Antarctic dust over the last glacialinterglacial transition. The records show that changes in the solubility of Li are associated with climatic changes. For the late glacial period and the Antarctic Cold Reversal (ACR) a large fraction, up to 75%, of the LiT content is present as insoluble minerals whereas for the Holocene period it seems that Li is present mainly as soluble salts (Li+). We compared the concentrations of Li+ with the concentrations of Ca2+ and the mass and size characte
Soluble and insoluble lithium dust in the EPICA DomeC ice core Implications for changes of the East Antarctic dust provenance during the recent glacial interglacial transition
C Barbante;
2007
Abstract
Continental dust impurities in Antarctic ice provide information on climate changes in the dust source areas and on past atmospheric circulation. We investigated records of dust species from the last 45 ka in the East Antarctic EPICA DomeC (EDC) ice core with special emphasis on the lithium (Li) content of dust. We obtained two complementary Li-records using a new Ion Chromatography (IC) technique in line with Inductively Coupled Plasma-Sector Field Mass Spectroscopy (ICP-SFMS). Concentrations of soluble Li (Li+) were obtained using IC, while total concentrations of Li (LiT) were obtained using ICP-SFMS, providing an ideal opportunity to investigate the soluble and insoluble chemistry of Li in East Antarctic dust over the last glacialinterglacial transition. The records show that changes in the solubility of Li are associated with climatic changes. For the late glacial period and the Antarctic Cold Reversal (ACR) a large fraction, up to 75%, of the LiT content is present as insoluble minerals whereas for the Holocene period it seems that Li is present mainly as soluble salts (Li+). We compared the concentrations of Li+ with the concentrations of Ca2+ and the mass and size characteI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
