82 research outputs found
Area industrializzata della Rada di Augusta (Siracusa): Relazione Tecnica sulla campagna di campionamenti subacquei Augusta 2012
Nell’ambito del progetto “Dinamica dei processi di evasione, trasporto e deposizione del mercurio nell’area industrializzata della Rada di Augusta e definizione delle mappe di rischio sanitario per le popolazioni residenti” realizzato dall’IAMC-CNR di Capo Granitola in collaborazione con l’ASP di Siracusa, il gruppo di biogeochimica dell’IAMC ha studiato i meccanismi biogeochimici che stanno alla base del fenomeno di rilascio di mercurio dai sedimenti della Rada di Augusta. Nel periodo compreso tra il 2011 e il 2012 l’ IAMC di Capo Granitola ha condotto diverse campagne di campionamenti nella Rada volte a rilevare la presenza e la quantità di mercurio in tutti i comparti ambientali (sedimenti marini, colonna d’ acqua, biota, atmosfera) e ad investigare i flussi di rilascio di mercurio dai sedimenti verso la colonna d’acqua e dalla colonna d’acqua verso l’atomosfera.
Il presente documento descrive in maniera approfondita le attrezzature e gli strumenti utilizzati dai tecnici per i campionamenti subacquei di sedimenti ed acqua e all’interfaccia sedimento-acqua e per le misure in situ di mercurio all’interfaccia acqua-atmosfera
Scale-Dependent Turbulent Dynamics and Phase-Space Behavior of the Stable Atmospheric Boundary Layer
The structure of turbulent dynamics in a stable atmospheric boundary layer was studied by means of a phase-space description. Data from the CASES-99 experiment, decomposed in local modes (with increasing time scale) using empirical mode decomposition, were analyzed in order to extract the proper time lag and the embedding dimension of the phase-space manifold, and subsequently to estimate their scale-dependent correlation dimension. Results show that the dynamics are low-dimensional and anisotropic for a large scale, where the flow is dominated by the bulk motion. Then, they become progressively more high-dimensional while transiting into the inertial sub-range. Finally, they reach three-dimensionality in the range of scales compatible with the center of the inertial sub-range, where the phase-space-filling turbulent fluctuations dominate the dynamics
European and Mediterranean mercury modelling: local and long-range contributions to the deposition flux
Mercury (Hg) is a global pollutant that is known to have adverse effects on human health, and most human exposure to toxic methylmercury is through fish consumption. Soluble Hg compounds in the marine environment can be methylated in the water column and enter the base of the food chain. Atmospheric deposition is the most important pathway by which Hg enters marine ecosystems. The atmospheric chemistry of Hg has been simulated over Europe and the Mediterranean for the year 2009, using the WRF/Chem model and employing two different gas phase Hg oxidation mechanisms. The contributions to the marine deposition flux from dry deposition, synoptic scale wet deposition and convective wet deposition have been determined. The Hg deposition fluxes resulting from transcontinental transport and local/regional emission sources has been determined using both Br/BrO and O3/OH atmospheric oxidation mechanisms. The two mechanisms give significantly different annual deposition fluxes (129 Mg and 266 Mg respectively) over the modelling domain. Dry deposition is more significant using the O3/OH mechanism, while proportionally convective wet deposition is enhanced using the Br/BrO mechanism. The simulations using the Br/BrO oxidation compared best with observed Hg fluxes in precipitation. Local/regional Hg emissions have the most impact within the model domain during the summer. A comparison of simulations using the 2005 and 2010 AMAP/UNEP Hg emission inventories show that although there is a decrease of 33% in anthropogenic emissions between the two reference years, the total simulated deposition in the regions diminishes by only 12%. Simulations using the 2010 inventory reproduce observations somewhat better than those using the 2005 inventory for 2009
Contribution of Volcanic and Fumarolic Emission to the Aerosol in Marine Atmosphere in the Central Mediterranean Sea: Results from Med-Oceanor 2017 Cruise Campaign
This work studied the contribution of the geogenic sources volcanoes and fumaroles to the aerosol in marine atmosphere in the central Mediterranean basin. For this purpose, in the framework of the Med-Oceanor measurement program, we carried out a cruise campaign in the summer of 2017 to investigate the impact to the aerosol of the most important Mediterranean volcanoes (Mount Etna, Stromboli Island, and Marsili Seamount) and solfatara areas (Phlegraean Fields complex, Volcano Islands, Ischia Island, and Panarea submarine fumarole). We collected PM10 and PM2.5 samples in 12 sites and performed chemical characterization to gather information about the concentration of major and trace elements, elemental carbon (EC), organic carbon (OC), and ionic species. The use of triangular plots and the calculation of enrichment factors confirmed the interception of volcanic plume. We integrated the outcomes from chemical characterization with the use of factor analysis and SEM/EDX analysis for the source apportionment. Anthropogenic and natural sources including shipping emissions, volcanic and fumarolic load, as well as sea spray were identified as the main factors affecting aerosol levels in the study area. Furthermore, we performed pattern recognition analysis by stepwise linear discriminant analysis to seek differences in the composition of PM10 and PM2.5 samples according to their volcanic or solfatara origin.This research was funded by the European Commission—H2020, the ERA-PLANET programme (www.era-planet.eu; contract no. 689443) within the IGOSP project (www.igosp.eu).Peer reviewe
The GOS4M Knowledge Hub: A web-based effectiveness evaluation platform in support of the Minamata Convention on Mercury
Abstract The Minamata Convention on Mercury was established to reduce the pressure on the environment caused by mercury by significantly reducing its emissions from anthropogenic activities. However, knowledge gaps still exist concerning emission inventories, emission factors and their integration in modelling frameworks. In addition, tools to facilitate communication between decision-makers and research groups providing measurement and modelling data are still scarce. This work presents the GOS4M Knowledge Hub, a public web application that provides an interactive and user friendly experience to access state-of-the-art modelling tools and data available in the literature. The Knowledge Hub currently integrates a Chemical Transport Model emulator, HERMES, coupled with a biogeochemical model, although it has been designed to house and deploy any number of different modelling components. Using the integrated dashboard, non-experts can perturb mercury releases from different anthropogenic emission sectors, simulating, for example, the application of Best Available Technologies, and then visualise in real-time the short- and long-term effects of the consequent reductions within a source-receptor framework. The dashboard also furnishes an estimate of the statistical significance of the changes in the model results. The analysis of a set of anthropogenic Hg emission reduction scenarios shows how an internationally coordinated effort would be necessary to achieve significant policy goals. It is important to note that the GOS4M Knowledge Hub yields the analysis presented here in a matter of seconds, compared to the days or weeks required by traditional modelling tools
Il Centro CISAS "Centro Internazionale di Studi Avanzati su Ambiente, Ecosistema e Salute Umana"
Il progetto CISAS, "Centro internazionale di studi avanzati su ambiente ed impatti su ecosistema e salute umana", finanziato con fondi del Fondo integrativo speciale per la ricerca (FISR) 2014 - 2015, articolo 2, comma 1, lettera b) Decreto legislativo 5 giugno 1998, n. 204, Delibera CIPE n. 105/2015 del 23 dicembre 2015, nell'ambito delle attività del Work Package 1 “Coordinamento, gestione e comunicazione”, ha previsto la creazione del Centro internazionale di studi avanzati su ambiente ed impatti su ecosistema e salute umana attraverso l'individuazione di spazi fisici dedicati alle attività avanzate di ricerca nell’ambito scientifico di riferimento del CNR
Scaling Properties of Atmospheric Wind Speed in Mesoscale Range
The scaling properties of turbulent flows are well established in the inertial sub-range. However, those of the synoptic-scale motions are less known, also because of the difficult analysis of data presenting nonstationary and periodic features. Extensive analysis of experimental wind speed data, collected at the Mauna Loa Observatory of Hawaii, is performed using different methods. Empirical Mode Decomposition, interoccurrence times statistics, and arbitrary-order Hilbert spectral analysis allow to eliminate effects of large-scale modulations, and provide scaling properties of the field fluctuations (Hurst exponent, interoccurrence distribution, and intermittency correction). The obtained results suggest that the mesoscale wind dynamics owns features which are typical of the inertial sub-range turbulence, thus extending the validity of the turbulent cascade phenomenology to scales larger than observed before
A Chemical Transport Model Emulator for the Interactive Evaluation of Mercury Emission Reduction Scenarios
Implementation of the Minamata Convention on Mercury requires all parties to "control, and where feasible, reduce" mercury (Hg) emissions from a convention-specified set of sources. However, the convention does not specify the extent of the measures to be adopted, which may only be analysed by decision-makers using modelled scenarios. Currently, the numerical models available to study the Hg atmospheric cycle require significant expertise and high-end hardware, with results which are generally available on a time frame of days to weeks. In this work we present HERMES, a statistical emulator built on the output of a global Chemical Transport Model (CTM) for Hg (ECHMERIT), to simulate changes in anthropogenic Hg (Hganthr) deposition fluxes in a source-receptor framework, due to perturbations to Hganthr emissions and the associated statistical significance of the changes. The HERMES emulator enables stakeholders to evaluate the implementation of different Hganthr emission scenarios in an interactive and real-time manner, simulating the application of the different Best Available Technologies. HERMES provides the scientific soundness of a full CTM numerical framework in an interactive and user-friendly spreadsheet, without the necessity for specific training or formation and is a first step towards a more comprehensive, and integrated, decision support system to aid decision-makers in the implementation of the Minamata Convention
Understanding mercury oxidation and air–snow exchange on the East Antarctic Plateau: a modeling study
Distinct diurnal and seasonal variations of mercury (Hg) have been observed in near-surface air at Concordia Station on the East Antarctic Plateau, but the processes controlling these characteristics are not well understood. Here, we use a box model to interpret the Hg0 (gaseous elemental mercury) measurements in thes year 2013. The model includes atmospheric Hg0 oxidation (by OH, O3, or bromine), surface snow HgII (oxidized mercury) reduction, and air-snow exchange, and is driven by meteorological fields from a regional climate model. The simulations suggest that a photochemically driven mercury diurnal cycle occurs at the air-snow interface in austral summer. The fast oxidation of Hg0 in summer may be provided by a two-step bromine-initiated scheme, which is favored by low temperature and high nitrogen oxides at Concordia. The summertime diurnal variations of Hg0 (peaking during daytime) may be confined within several tens of meters above the snow surface and affected by changing mixed layer depths. Snow re-emission of Hg0 is mainly driven by photoreduction of snow HgII in summer. Intermittent warming events and a hypothesized reduction of HgII occurring in snow in the dark may be important processes controlling the mercury variations in the non-summer period, although their relative importance is uncertain. The Br-initiated oxidation of Hg0 is expected to be slower at Summit Station in Greenland than at Concordia (due to their difference in temperature and levels of nitrogen oxides and ozone), which may contribute to the observed differences in the summertime diurnal variations of Hg0 between these two polar inland stations.National Science Foundation (U.S.) (Grant ACP-1053648
Rapporto tecnico sulle attività di campionamento della “Campagna Oceanografica CISAS_1” Augusta-Priolo 19-23 ottobre 2017
Le attività di campionamento ed acquisizione dati svolte durante la campagna CISAS_1 si inseriscono in seno al progetto “Centro internazionale di studi avanzati su ambiente ed impatti su ecosistema e salute umana (CISAS)” del CNR. Tra gli obiettivi principali del progetto, lo sviluppo di una complessa e decisa azione di ricerca scientifica volta ad una profonda comprensione dei fenomeni di inquinamento ambientale e dei loro risvolti sull’ecosistema e la salute umana. Le aree di indagine del progetto sono rappresentate dai Siti di Interesse Nazionale di Priolo, Milazzo-Pace del Mela e Crotone che, per specificità e modalità di impatto antropogenico sull’ambiente, l’ecosistema e la salute umana, coprono un ampio spettro di tipologie di interesse
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