A multi-year record of atmospheric mercury species at a background mountain station in Andean Patagonia (Argentina): Temporal trends and meteorological influence

DIÉGUEZ, MARÍA C.; BENCARDINO, MARIANTONIA; GARCIA, PATRICIA E.; D'AMORE, FRANCESCO; CASTAGNA, JESSICA; DE SIMONE, FRANCESCO; CARDENAS, CAROLINA SOTO; GUEVARA, SERGIO RIBEIRO; PIRRONE, NICOLA; SPROVIERI, FRANCESCA

ATMOSPHERIC ENVIRONMENT

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2019

1352-2310

This work provides the first continuousmeasurements of atmospheric mercury (Hg) at the EMMA Station in Patagonia(Argentina), within the Southern Volcanic Zone of South America. Thismonitoring site was set up by the Global Mercury Observation System (GMOS project)and is located inside Nahuel Huapi National Park (41°07´43.33"S,71°25´12.03"W; 800 m a.s.l) in a forested valley of the Andes upwind ofSan Carlos de Bariloche city. This study aimed at describing atmospheric Hglevels and trends of variation using concentration data of Gaseous ElementalMercury (GEM) collected from October 2012 to July 2017 and, Gaseous OxidizedMercury (GOM) and Particle-Bound Mercury (PBM) recorded from March 2014 untilJuly 2017. During the studied period the mean GEM concentration was 0.86 ± 0.16ng m-3; with the highest level in theaustral spring (0.95 ± 0.13 ng m-3) and the lowest in the autumn (0.80 ± 0.15 ng m-3). Mean GOM concentration was 4.61 ± 4.00 pg m-3, displaying the highest level inautumn (5.47 ± 4.39 pg m-3) and the lowest in winter (1.24 ± 0.90 pg m-3). Mean PBM computed for the whole period was3.74 ± 3.41 pg m-3; with the highestmean levels recorded in autumn (6.32 ± 3.41 pg m-3) and the lowest in spring (1.18 ± 0.92 pg m-3). Daytime levels of GEM, GOM andPBM were higher than nighttime concentrations, although in the case GOM and PBMsimilar levels were computed in autumn and summer, respectively. Westerly windsalong with temperature and relative humidity influenced the dynamics of GEM,GOM and PBM at the EMMA Station. The HYSPLIT model showed that the area of theEMMA station was simultaneously affected by local and regional sources (forestfires and volcanoes) while the lowest values were recorded with the inflow ofclean oceanic air masses coming from the free troposphere and corresponding toa long-range transport. Moreover, the Potential Source Contribution Functionanalysis showed that emissions in the Marine Boundary Layer, deriving fromremote areas of Pacific Ocean are sources of GEM and GOM.