title: Multi-year record of atmospheric and snow surface nitrate in the central Antarctic plateau.
abstract: Continuous all year-round samplings of atmospheric aerosol and surface snow at high (daily to 4-day) resolution were carried out at Dome C since 2004-05 to 2013 and nitrate records are here presented. Basing on a larger statistical data set than previous studies, results confirm that nitrate seasonal pattern is characterized by maxima during austral summer for both aerosol and surface snow, occurring in-phase with solar UV irradiance. This temporal pattern is likely due to a combination of nitrate sources and post-depositional processes whose intensity usually enhances during the summer. Moreover, it should be noted that a case study of the synoptic conditions, which took place during a major nitrate event, showed the occurrence of a stratosphere-troposphere exchange. The sampling of both matrices at the same time with high resolution allowed the detection of a an about one-month long recurring lag of summer maxima in snow with respect to aerosol. This result can be explained by deposition and post-deposition processes occurring at the atmosphere-snow interface, such as a net uptake of gaseous nitric acid and a replenishment of the uppermost surface layers driven by a larger temperature gradient in summer. This hypothesis was preliminarily tested by a comparison with surface layers temperature data in the 2012-13 period. The analysis of the relationship between the nitrate concentration in the gas phase and total nitrate obtained at Dome C (2012-13) showed the major role of gaseous HNO3to the total nitrate budget suggesting the need to further investigate the gas-to-particle conversion processes.
authors.affiliation: Dept. of Chemistry "Ugo Schiff", University of Florence, Sesto F.no, Florence, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Traversi
authors.affiliation: Dept. of Chemistry "Ugo Schiff", University of Florence, Sesto F.no, Florence, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Becagli
authors.affiliation: IFAC-CNR, Sesto F.no, Florence, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Brogioni
authors.affiliation: Dept. of Chemistry "Ugo Schiff", University of Florence, Sesto F.no, Florence, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Caiazzo
authors.affiliation: ENEA, Laboratory for Observations and Analyses of the earth and Climate (SSPT-PROTER-OAC), Rome.
authors.forename: V
authors.initials: V
authors.lastname: Ciardini
authors.affiliation: Dept. of Chemistry "Ugo Schiff", University of Florence, Sesto F.no, Florence, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Giardi
authors.affiliation: Université Grenoble Alpes, CNRS, Laboratoire de Glaciologie et Géophysique de l'Environnement (LGGE), Grenoble, France.
authors.forename: M
authors.initials: M
authors.lastname: Legrand
authors.affiliation: IFAC-CNR, Sesto F.no, Florence, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Macelloni
authors.affiliation: ISAC-CNR, Bologna, Italy.
authors.forename: B
authors.initials: B
authors.lastname: Petkov
authors.affiliation: Université Grenoble Alpes, CNRS, Laboratoire de Glaciologie et Géophysique de l'Environnement (LGGE), Grenoble, France.
authors.forename: S
authors.initials: S
authors.lastname: Preunkert
authors.affiliation: ENEA, Laboratory for Observations and Analyses of the earth and Climate (SSPT-PROTER-OAC), Rome.
authors.forename: C
authors.initials: C
authors.lastname: Scarchilli
authors.affiliation: Dept. of Chemistry "Ugo Schiff", University of Florence, Sesto F.no, Florence, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Severi
authors.affiliation: ISAC-CNR, Bologna, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Vitale
authors.affiliation: Dept. of Chemistry "Ugo Schiff", University of Florence, Sesto F.no, Florence, Italy; ISAC-CNR, Bologna, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Udisti
mesh_terms: D000864:Antarctic Regions; D001272:Atmosphere / Q000737:chemistry*; D004784:Environmental Monitoring; D009566:Nitrates / Q000032:analysis* / Q000737:chemistry; D012621:Seasons; D012914:Snow / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D009566:Nitrates
keywords: Aerosol; Antarctica; Dome C; Nitrate; Stratosphere-troposphere exchange; Surface snow