Sea-spray deposition in Antarctic coastal and plateau areas from ITASE traverses

• Published in: Annals of Glaciology
• Main Authors: Benassai, Silvia, Becagli, Silvia, Gragnani, Roberto, Magand, Olivier, Proposito, Marco, Fattori, I., Traversi, Rita, Udisti, Roberto
• Other Authors: Department of Chemistry, Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2005
• Subjects: [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology; Antarctic; East Antarctica; Victoria Land; Wilkes Land; Annals of Glaciology; Antarc*; Antarctica
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-00373752; https://hal-insu.archives-ouvertes.fr/insu-00373752/document; https://hal-insu.archives-ouvertes.fr/insu-00373752/file/sea-spray-deposition-in-antarctic-coastal-and-plateau-areas-from-itase-traverses.pdf; https://doi.org/10.3189/172756405781813285

International audience Sea-salt markers (Na+, Mg2+ and Cl−) were analyzed in recent snow collected at more than 600 sites located in coastal and central areas of East Antarctica (northern Victoria Land-Dome C-Wilkes Land), in order to understand the effect of site remoteness, transport efficiency and depositional and post-depositional processes on the spatial distribution of the primary marine aerosol. Firn-core, snow-pit and 1 m integrated superficial snow samples were collected in the framework of the International Trans-Antarctic Scientific Expeditions (ITASE) project during recent Italian Antarctic Campaigns (1992-2002). The sampling sites were mainly distributed along coast-inland traverses (northern Victoria Land- Dome C) and an east-west transect following the 2100 m contour line (Wilkes Land). At each site, the snow ionic composition was determined. Here, we discuss the distribution of sea-spray components (Na+, Mg2+ and Cl−) as a function of distance from the sea, altitude and accumulation rate, in order to discover the pulling-down rate, possible fractionating phenomena and alternative sources moving inland from coastal areas. Sea-spray depositional fluxes decrease as a function of distance from the sea and altitude. A two-order-of-magnitude decrease occurs in the first 200 km from the sea, corresponding to about 2000 ma.s.l. Correlations of Mg2+ and Cl− with Na+ and trends of Mg2+/Na+ and Cl−/Na+ ratios showed that chloride has other sources than sea spray (HCl) and is affected by post-depositional processes. Accumulation rate higher than 80 kg m−2a−1 preserves the chloride record in the snow. Seaspray atmospheric scavenging is dominated by wet deposition in coastal and inland sites.