1,721,129 research outputs found
Regulating Ecosystem Services of forests in ten Italian Metropolitan Cities: Air quality improvement by PM10 and O3 removal
No full textUrban and periurban forests, which are integrated within the concept of Green Infrastructure, provide important Ecosystem Services, including air purification. In this study, we quantified the Ecosystem Service of particulate matter (PM10) and Ozone (O3) removal from urban and periurban forests in ten metropolitan cities in Italy, and its total monetary value. In order to gain a better understanding of how Ecosystem Services can be regulated on a wider scale, the vegetation ecosystem types were grouped into Physiognomic-Structural Categories of Vegetation according to morphofunctional criteria. The pollution removal was mapped using a remote sensing and GIS approach, by applying a deposition model and a stomatal flux model. We estimated, for the ten metropolitan cities, an overall pollution abatement of 7150 Mg of PM10 and 30,014 Mg of O3 in the year 2003, which was an extremely hot year. Our findings indicate that structural characteristics (i.e. Leaf Area Index) and functional diversity, linked to stomatal conductance, exert a marked influence on the provision of the regulating Ecosystem Services, whose total monetary value was estimated to be equal to 47 and 297 million USD for PM10 and O3 removal, respectively. This study represent the first national-scale assessment of the Ecosystem Services of air pollution removal in Europe, thus providing information that may be useful to stakeholders to manage Green Infrastructure more efficiently. © 2016 Elsevier Ltd. All rights reserved
Modelling dispersion of smoke from wildfires in a Mediterranean area
No full textWe present a modelling system for the estimation of forest fire emissions (prebolchem-fire) and their inclusion in the atmospheric composition model BOLCHEM. Emission fluxes have been estimated following the methodology proposed by Seiler and Crutzen (1980) and using MODIS 'burned area product'. Then they are modulated following the WRAP approach (WRAP, 2005). This approach is also used for the estimations of fire emission height. Model simulations have been performed for the period 22-30 August 2007, in which fires were most severe in Greece, Albania and Algeria. The estimated emission fluxes have been compared with those estimated by the global model FINNv1 (fire inventory from NCAR) and the difference between the two emissions have been discussed. The modelled concentration of black carbon aerosol is compared with measurements at PEARL station lidar, Tito Scalo, Potenza (40.63ᄚN, 15.80ᄚE, 760 m asl), Italy, on 30 August 2007. We discuss the discrepancies between the measured and modelled vertical distribution concentrations of black carbon aerosol, probably due to uncertainties related to the estimation of the total flux and of the injection height of the smoke
H15-95: Uncertainty factors in modelling dispersion of smoke from wild fires in a mediterranean area
No full textWe present a modelling system for the estimation of forest fire emissions (prebolchem-fire) and their inclusion in the atmospheric composition model BOLCHEM. Emission fluxes have been estimated following the methodology proposed by Seiler and Crutzen (1980) and using MODIS "Burned Area Product". Then they are modulated following the WRAP approach (WRAP Fire emission inventory 2005). This approach, integrated with information from a lagrangian backward model, is also used for the estimations of fire emission height. Model simulations have been performed for the period 22 - 30 August 2007, in which fires were most severe in Greece, Albania and Algeria. The emissions fluxes estimated for the gas species CO, NOx, SO2 and NH3 and the particulate matter PM2.5 and PM10 have been compared with those estimated by the global model FINNv1 (Fire Inventory from NCAR) and the difference between the two emissions have been discussed. To put into evidence the sensitivity of the results to the modulation of emission fluxes and height, modelling simulations have been performed with different model settings. Moreover, the concentrations of black carbon aerosol predicted by the model are compared with measurements at Tito Scalo, Potenza (40.63oN, 15.80oE, 760 m asl), where an unusual layer of aerosol was detected by the PEARL station lidar on 30 August 2007. We discuss the discrepancies between the measured and modelled vertical distribution concentrations of black carbon aerosol, probably due to uncertainties related to the estimation of the total flux and of the injection height of the smoke
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Heavy metal modelling study over Italy: Effects of grid resolution, lateral boundary conditions and foreign emissions on air concentrations
No full textHeavy metals (HMs) are pollutants that have both anthropogenic and natural sources. In the last decade, the European Commission (EC) has imposed limit and target values for some of them that are toxic both for humans and for the environment. This study aims to assess the HM concentrations over Italy by means of the atmospheric modelling system (AMS) of the MINNI project. The AMS is based on the chemical transport model (CTM) FARM. The sensitivity of model simulations to horizontal grid resolution, lateral boundary conditions and the contribution of emissions from neighbouring countries has been also evaluated. The simulations have been carried out for the year 2005 considering a spatial resolution of 20 km over the Italian domain and 4 km over northern Italy (Po Valley). The CTM has been extended to take into account the HMs considered by EC directives such as arsenic (As), cadmium (Cd), nickel (Ni) and lead (Pb). Both anthropogenic and natural emissions have been considered in this study. Model results have been compared with available observations. Results show realistic concentration of HMs and suggest the importance of using boundary conditions, while foreign emissions have less impact. In addition, the present work highlights the necessity of more observations in space and time for a comprehensive validation of the model. High-resolution simulation gives more realistic pattern with respect to the low-resolution one for the highly polluted areas. However, future improvements require a better knowledge of the space/time distribution of the emissions, currently not available. © 2015 Springer International Publishing Switzerland
Properties of agricultural aerosol released during wheat harvest threshing, plowing and sowing
No full textThis study shows for the first time a chemical and morphological characterization of agricultural aerosols released during three important agricultural operations: threshing, plowing and sowing. The field campaigns were carried out in the eastern part of the Po Valley, Italy, in summer and autumn 2009. The aerosol particles were sampled on quartz fiber filters and polytetrafluoroethylene membranes in order to allow Inductively Coupled Plasma Mass Spectrometry (ICP-MS) analysis and Scanning Electron Microscopy equipped with an Energy Dispersive X-ray Spectrometer (SEM-EDS) investigations, respectively. The organic carbon mass concentrations were measured with a Sunset Laboratory Dual-Optical Organic Carbone/Elemental Carbon (OCEC) Aerosol analyzer. The morphological and chemical analyses by SEM-EDS allowed recognizing four main particle classes: organic, silica, calcite and clay minerals. The organic particles contribute to both fine and coarse aerosol fractions up to ca. 50% for all three agricultural activities. This was also confirmed by OCEC analysis for fine fraction. Most of the agricultural aerosols, about 60%, were single particles and the remaining 40% were agglomerations of particles. The ICP-MS results showed that threshing and plowing produce more aerosol particles than sowing, which was characterized by important amounts of clay minerals produced from land soils. © 2014
A study of heavy metals pollution in Italy with the atmospheric modelling system of the MINNI project
No full textThis work shows preliminary results for heavy metals concentrations simulated with the atmospheric modelling system (AMS) of the MINNI project. The simulation has been carried out for the year 2005 with a horizontal resolution of 25 km. The simulated concentrations of As, Cd, Ni and Pb have, in general, the highest values in urban and industrial areas and compare well with available measurements. © Owned by the authors, published by EDP Sciences, 2013
Presentation of the EURODELTA III inter-comparison exercise - Evaluation of the chemistry transport models performance on criteria pollutants and joint analysis with meteorology
No full textThe EURODELTA III exercise allows a very comprehensive inter-comparison and evaluation of chemistry transport models performance. Participating models were applied over four different one month period, within a rather limited number of years (from June 2006 to March 2009) thus allowing evaluating the influence of different meteorological conditions on model performance. The exercise was performed under strict requirements concerning the input data. As a consequence, there were very limited differences in the models set up, representing a sort of sensitivity analysis to several aspects of the modelling chains. The models were evaluated mainly on background stations. Even if the meteorology was prescribed, some variables like the planetary boundary layer (PBL) height, the vertical diffusion coefficient are diagnosed in the model pre-processors and explain the spread of models results. For ozone, this study shows the importance of boundary conditions on model calculations and then on the regime of the gas and particle chemistry. The worst performances are observed for sulphur dioxide concentrations that are poorly captured by the models. The performances of models are rather good very similar for the nitrogen dioxide. On average, the models provide a rather good picture of the particulate matter (PM) concentrations over Europe even if the highest concentrations are underestimated. For the PM, the mean diurnal cycles show a general tendency to overestimate the effect of the PBL height rise while the afternoon chemistry (formation of secondary species) is certainly underestimated, PM observations show very flat diurnal profiles whatever the season. In general the day time PBL height is underestimated by all models, the largest variability of predicted PBL is observed over the ocean and seas. More generally, in most cases model performances are more influenced by the model setup than the season. The temporal evolution of wind speed is most responsible of model skilfulness in reproducing the daily variability of pollutant concentrations (e.g. the development of peak episodes), while the reconstruction of the PBL diurnal cycle seems more influencing in driving the corresponding pollutant diurnal cycle and hence the presence of systematic positive and negative biases detectable on daily basis. © Author(s) 2016
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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