Il mercurio atmosferico nel North della Patagonia (Sud della zona vulcanica del Sud America): sorgenti, speciazione, pattern delle concentrazioni a differenti scale temporali e drivers ambientali.

Responsabili di progetto

Francesca Sprovieri, Maria Del Carmen Dieguez

Accordo

ARGENTINA - CONICET - Consejo Nacional de Investigaciones Científicas y Técnicas

Bando

CNR/CONICET biennio 2017-2018 2017-2018

Dipartimento

Scienze del sistema terra e tecnologie per l'ambiente

Area tematica

Scienze del sistema Terra e tecnologie per l'ambiente

Stato del progetto

Rinnovo

Relazione per il rinnovo

joint-report-cnr-conicet-cooperation-project-2015-2016.pdf

Proposta di ricerca

This proposal is aimed to support ongoing and programmed activities between research groups of the IIA (CNR Italy, Rende Division; PI: Dr. Francesca Sprovieri) and Photobiology Laboratory (INIBIOMA-CONICET; PI: Dr. María C. Diéguez) framed in the projects Global Mercury Observation System - GMOS (FP7), Agencia FONCyT PICT 2015-3496 (approved) and PICT 2016-0499 (submitted). The overall goal is to measure and analyze atmospheric mercury (Hg) concentrations and fluxes (wet and dry deposition) in Northern Andean Patagonia, Nahuel Huapi National Park (NHNP) focusing on Hg speciation, its input on natural ecosystems of the area, to ultimately perform regional and global scale modeling application on Hg fluxes considering environmental drivers. The project aims also to sustain the monitoring of atmospheric Hg at the EMMA Station (INIBIOMA-CONICET, Bariloche), established in 2011 as the southernmost master station of the GMOS, the unique global network established in the framework of the GMOS project, which integrates other regional networks and supports international programs (i.e.,GEO/GEOSS). The Hg biogeochemical interactions have still numerous uncertainties; however, ongoing research efforts of international networks are devoted to fill existing gaps in the fate and transport pathways of Hg in the environment. In aquatic systems of Patagonia, high to moderate levels of Hg have been detected in different environmental compartments with prevalence of Hg2+ in the dissolved phase and high bioaccumulation potential of pelagic basal organisms (plankton). The source of Hg appears to be natural, coming from frequent eruptions of volcanoes located at the west of the Andes and also from biomass burning (forest fires). The climate of the region is suffering strong fluctuations in the precipitation regime, increased temperature and solar radiation levels (particularly UV), that considered together with the frequent volcanic eruptions and forest fires, have a high potential to drive Hg fluxes and the fate of Hg in natural systems. Although research lines focusing in Hg dynamics and fluxes in the region have enhanced our knowledge about Hg in the Andean Patagonian lacustrine sector of the Southern Volcanic Zone of South America, there is urgent regional need to establish the sources and atmosphere-land-freshwater transfers and the potential for re-emission of this heavy metal to the atmosphere. Our proposal, therefore, relies on the outcome of the last four years obtained in the framework of the GMOS project and the research activities performed within the last CNR-CONICET cooperation projects which lead us to hypothesize that Hg transported in the atmosphere originates mostly in the active volcanic stretch of the Andes (SVZ) and is transported by westerly winds. Local climatic conditions imposed by the Andes cordillera and the action of strong westerlies produce sharp W-E gradients of temperature, humidity, radiation and precipitation which are key factors determining the incidence of Hg at the East of the Andes, particularly in the NHNP. In this line, we suppose that the regional meteorology, particularly the marked seasonal precipitation pattern, along with the predominant W-E wind direction favor moderate but continuous baseline inputs of total Hg. Besides, the marked precipitation regime of the area characterized by a wet season (austral autumn and winter) and a dry season (austral spring and summer) will reflect on Hg deposition which will show a seasonal pattern with wet Hg deposition concentrated in the wet season and dry particulate Hg deposition favored on the dry season. In addition, the high levels of solar radiation (particularly the UV wavelengths) experienced in the Andean region, operate through photochemical reactions to transform Hg transported in the air as well as the Hg deposited and stored in terrestrial and aquatic environments and the re-emission to the atmosphere. Thus, natural fluctuations of solar radiation levels are expected to determine Hg fluxes and the levels of Hg0 on daily and seasonal bases. Our research in this proposal will ensure the continuity of atmospheric levels monitoring of Hg species and in precipitation (rain and snow) inside NHNP in order to perform modeling application on regional and global scale based on data recorded to study atmospheric Hg processes and dynamics as well as its annual, inter-annual, seasonal and daily patterns and processes in Patagonia. In particular, the study contemplates the sampling of air and precipitation at the EMMA Station. Meteorological variables, ground-based solar irradiance, and atmospheric Hg and deposition will be measured in continuous using the equipment available in the EMMA Station. The data collected are automatically uploaded to a general data base using the software packages Weatherlink (Davies) and DASWIN. Hg concentrations will be measured (and are currently measured) using an automated system Tekran (Tekran Inc., Canada modules 2537b, 1130 and 1135). The precipitation samples will continue to be collected using an automated precipitation system (N-con, model Mercury Deposition Network), over a period of 15 days under the GMOS precipitation protocol. Samples are stored at 5ºC until sent to the CNR-IIA for THg analysis. All the data from the continuous air Hg monitoring is loaded and will continue to be loaded in near real time in an internal database. Once a week the database is updated in the Station profile of the GMOS server (http://sdi.iia.cnr.it/geoint/publicpage/GMOS/sdi; user and password protected). Hg data management follows the GMOS Data Quality Management (G-DQM) based on the standard procedures, which enables the QA/QC of raw data retrieved from the remote stations. The validated data will be analyzed to fulfill the specific objectives of the proposal in order to describe the patterns of Hg concentrations, speciation at different timescales useful for modeling applications.

Obiettivi della ricerca

The following specific objectives of this proposal rely on the continuous operation of the EMMA station in the suburbs of San Carlos de Bariloche (Nahuel Huapi National Park, North Patagonia) to:
1- secure the continuity of the monitoring of atmospheric levels of Hg species (Hg0, GOM and PBM) and Total Hg in precipitation (rain and snow samples) inside Nahuel Huapi National Park (NHNP) and their dynamics at different time scales (daily, seasonal, annual, interannual);
2-To monitor ancillary meteorological parameters and some pollutants known to relate/determine atmospheric Hg fluxes: a) precipitation; b) ground based levels of solar radiation (photosynthetically active radiation PAR, UVA and UVB), c) temperature; d) carbon dioxide (CO2), e) ozone and, f) basic meteorological parameters (wind speed and direction, humidity, etc.);
3- To analyze, describe and model the annual, interannual, seasonal and daily patterns of atmospheric Hg fluxes inside NHNP using data collected in the EMMA Station from 2012 up to present: applies to GEM, GOM, PBM and THg aiming to provide information about the source and pattern of the Hg in the atmosphere at a regional/local scale (Patagonia);
4-To integrate regional/local information at a global scale through the global network (GMOS).

Ultimo aggiornamento: 24/06/2025