Heat-Wave Events in Spain: Air Mass Analysis and Impacts on 7

The present paper describes and characterizes the air mass circulation during the heat-wave events registered during the period 2005-2014 over Spain, paying special attention on the role of the Saharan circulations. With this purpose, backward trajectories at 500, 1500 and 3000 m in Seville (south), Madrid (centre) and Bilbao (north) during the thirteen heat-wave events identified during this period are analysed. Finally, the impact of the heat-wave events and of each advection pattern on 7Be activity concentrations is also analysed. The air mass results indicate that the heat-wave events are characterized roughly by western, southern and nearby advections, with a higher frequency of the first two types. The analysis shows a general and large impact at lower levels of westerly flows and an increase of African air masses with height. The Saharan air masses present a different spatial impact over Spain, with a decreasing occurrence and a decrease in the simultaneous occurrence percentage from south to north. The 7Be activity concentrations during these events show an increase of concentrations in central and southern areas and a small decrease in northern Spain. This increase is not associated with Saharan air masses, but instead to the arrival of distant westerly air masses.JRC.G.II.7-Nuclear securit

A new approach for roughness representation within urban dispersion models

The effects of green infrastructure on pollutant concentrations are greatly variable, essentially depending on the surrounding built-up environment and on local meteorological conditions. To simulate the effects of the presence of trees at urban scale, a reliable methodology is the Computational Fluid Dynamics (CFD) approach, however it needs high calculation costs. An alternative integral dispersion model is given by provided that a suitable parameterization for vegetation is included. In this work, we have developed and demonstrated a novel methodology, based on aerodynamic parameters, to include the aerodynamic effect of trees in an operational dispersion model, the ADMS-Urban. The aerodynamic parameters were derived using the morphometric method starting from open data containing information on buildings and trees. The new roughness parameter calculation method has produced the urban spatially varying roughness (USVR) and it was evaluated in different scenarios at the urban and neighborhood scale. The numerical outputs of the simulations were compared with observations from reference air quality stations collected within an ad-hoc intensive field campaign conducted in 2017 in the city of Bologna, Italy. The results of the comparison highlight that the introduction of the aerodynamic effects of buildings lead to great improvements in the performance of the model at both spatial scales and for the different study sites considered in this study. Conversely, the inclusion of trees in the calculation produces significant improvements only when conducting studies at high spatial resolution and for densely vegetated areas

Terrestrial gamma dose rate mapping (Euganean Hills, Italy): comparison between field measurements and HPGe gamma spectrometric data

Terrestrial gamma radiation is mostly due to radionuclides in soil and rocks, primarily the 238U, 235U and 232Th radioactive families and 40K. This radiation contributes 15% to public exposure from all ionizing radiation sources, considering global population. Moreover, it can be used to estimate radon flux and included as one of the quantities relevant to the geogenic radon hazard model. Therefore, effort has been put into developing maps of terrestrial gamma dose rate at the regional, national or European scale, using different input data and methods. In the present work, two distinct approaches to map terrestrial gamma dose rate have been tested in the Euganean Hills district of NE Italy. The first one is based on 41 in situ measurements of ambient dose equivalent rates using a rate meter equipped with a NaI scintillator probe. The second one estimates terrestrial gamma dose rate from the U, Th and K activity concentrations in rock samples collected at the same locations of the dose rates measurements. The results obtained indicate good agreement between the two approaches, and as such suggest that the UNSCEAR 2008 prescription to derive ambient dose equivalent rate from laboratory gamma measurements produces reliable data, provided that cosmic and fall-out contributions are included. Moreover, the study proved that mapping the ambient dose equivalent rate (or terrestrial gamma dose rate) using only one database – i.e. either measured data or estimates derived from radionuclide activity concentration – yields valid results

Relazione fra turbolenza atmosferica e qualit\ue0 dell\u2019aria in due street canyon nella citt\ue0 metropolitana di Bologna

Il presente studio si inserisce all\u2019interno del progetto Horizon H2020 iSCAPE (Improving the Smart Control of Air Pollution in Europe) che si propone di acquisire conoscenze sulle interazioni tra clima urbano e inquinamento atmosferico in alcune citt\ue0 europee. La citt\ue0 metropolitana di Bologna \ue8 stata selezionata come citt\ue0 pilota in quanto sita all\u2019interno della Pianura Padana, ben noto hot- spot in termini di qualit\ue0 dell\u2019aria. In aggiunta, essa \ue8 caratterizzata da aree densamente edificate e trafficate, come i canyon urbani, dove \ue8 interessante caratterizzare la qualit\ue0 dell'aria, la dinamica atmosferica e la turbolenza. A tal fine sono state effettuate due campagne di monitoraggio intensivo (estate 2017 e inverno 2018) in due differenti street-canyon (via Marconi e via Laura Bassi) situati all\u2019interno della citt\ue0, caratterizzati dalla stessa orientazione geografica e simile volume di traffico, ma da diversa struttura geometrica e presenza di alberazione (presente solamente in via Laura Bassi). Per le misurazioni sono stati utilizzati due laboratori mobili di Arpae Emilia-Romagna per la rilevazione di PM10, PM2.5, NOx, CO, O3, BTEX. In aggiunta, sono stati installati anemometri sonici e termoigrometri a diversi livelli all'interno e al di sopra dei canyons (Laura Bassi/Marconi: 3/4m \u2013 9/8m \u2013 15/25m) per la caratterizzazione della turbolenza atmosferica. L\u2019analisi dei dati osservati sar\ue0 integrata con l\u2019uso di modelli numerici: ADMS Urban per valutare la distribuzione degli inquinanti a scala cittadina; modelli CFD per ricostruire la circolazione all\u2019interno dei canyon urbani. Inoltre nel corso delle campagne sono state effettuate misure termometriche degli edifici per valutare la dinamica dell\u2019isola di calore urbano. Fin dalla campagna estiva \ue8 apparso evidente l\u2019effetto di amplificazione dello street canyon sulle concentrazioni di inquinanti, in particolare gli NOx, noti precursori di aerosol, presentano concentrazioni medie orarie doppie rispetto al resto della citt\ue0 e medie al minuto che raggiungono valori prossimi al fondoscala strumentale. In questo contesto, le concentrazioni vengono analizzate in funzione della turbolenza atmosferica e delle forzanti termiche interne al canyon, in quanto uniche responsabili, in assenza di condizioni sinottiche, del trasporto degli inquinanti

Soil gas radon assessment and development of a radon risk map in Bolsena, Central Italy

Vulsini Volcanic district in Northern Latium (Central Italy) is characterized by high natural radiation background resulting from the high concentrations of uranium, thorium and potassium in the volcanic products. In order to estimate the radon radiation risk, a series of soil gas radon measurements were carried out in Bolsena, the principal urban settlement in this area NE of Rome. Soil gas radon concentration ranges between 7 and 176 kBq/m(3) indicating a large degree of variability in the NORM content and behavior of the parent soil material related in particular to the occurrence of two different lithologies. Soil gas radon mapping confirmed the existence of two different areas: one along the shoreline of the Bolsena lake, characterized by low soil radon level, due to a prevailing alluvial lithology; another close to the Bolsena village with high soil radon level due to the presence of the high radioactive volcanic rocks of the Vulsini volcanic district. Radon risk assessment, based on soil gas radon and permeability data, results in a map where the alluvial area is characterized by a probability to be an area with high Radon Index lower than 20 %, while probabilities higher than 30 % and also above 50 % are found close to the Bolsena village

Valutazione dell'impatto ambientale delle emissioni in atmosfera nel distretto di cairo Montenotte (SV) - relazione di consulenza tecnica: Procedimento Nr. 653/14 Procura della repubblica di Savona

Risultati della campagna di monitoraggio gas e PM10 ed analisi di source apportionmen

Indagine ambientale per la rilevazione di inquinanti atmosferici mediante modelli a recettore del distretto monfalconese (Procedimento nr. 1213/13 R.N.R.I. Procura della Repubblica di Gorizia)

Risultati di una campagna di monitoraggio di gas e particolato atmosferico nell'area di Monfalcone - Studio del profilo delle sorgenti di emissione del distrett

Aerosol Characterization At The WMO-GAW Station of Mt. Cimone (2165 m a.s.l.) by 7Be, 210Pb and PM10

Measurements of airborne radionuclides 7Be ,210Pb and PM10 have been routinely carried out together with aerosol mass concentration at the WMO-GAW station of Mt. Cimone (Northern Apennines, Italy) with the aim to obtain basic information on aerosol behavior at this site. Several years of data (the experimental activity, started in January 1998) are presented and discussed in this paper. Aerosol collection is carried out by filtration with a high-volume PM10 sampler for 48 hours. Activities of 7Be and 210Pb were measured by non-destructive \uf067-ray spectrometry and aerosol mass concentration was determined gravimetrically. A distinct seasonal cycle is observed for 7Be, 210Pb and PM10, with maxima in the summer and minima in the winter. The opposite trend is observed for the activity ratio 7Be/210Pb, used as an indicator of vertical transport. Variability of the three parameters at this site is discussed by means of statistical tools such as t-test analysis classification as well as by back-trajectory approac

An outstanding Saharan dust event at Mt. Cimone (2165 m a.s.l., Italy) in March 2004

Dust outbreaks are very common throughout the year, with a peak frequency in spring (March, April, May) towards the Atlantic Ocean, or in late spring/summer (May, June, July) towards the Mediterranean Sea (even if winter and especially autumn events, though less frequent, are usually very intense). Every year strong winds blowing over the Sahara desert lift hundreds of millions of tons of dust high into the sky over North Africa. In 2004, from 13 to 15 March, a severe PM episode was observed at Mt. Cimone. Figure 1, showing the trend of PM10, 210Pb, number of fine and coarse particles, for the year 2005, highlights a clear increase of all these parameters during the Saharan Dust episode. In particular, PM concentration exceeded 80 μg/SCM, a value seven times greater than the mean level during the preceding and subsequent days, and the maximum PM10 concentration recorded at Mt Cimone in more than 12 years observations. This episode has been ascribed to a long lasting Saharan dust outbreak, starting at the beginning of March, and first impacting the Atlantic Ocean and then the Mediterranean area. This event originated from the Bodele depression in northern Chad, a remarkable as well as well recognized source of mineral dust, and the analysis of aerosol optical depth revealed that dustiness conditions occurred along the entire ITCZ. On 5th March 2004 images from the visible channel of the SeaWIFS satellite show a huge, dense, meridionally oriented dust plume off the northwestern African coast from west of Madeira to Cape Verde, sustained by hazy and prolonged Harmattan conditions. This plume spreads laterally, moves westward and formed an arc more than 5000 km long from Guinea to the northern tip of Morocco. The plume crossed the Atlantic Ocean and impacted onto the Caribbean region. At the end of this extraordinary episode, the sequence of two main meteorological patterns: 1) the penetration of an upper-level trough to low latitudes with a minimum centered over the North-western Algerian coast; and 2) a Sahara high extending all over the Mediterranean Sea with an elongated north-eastward tongue, mobilized dust to the south of the northern Atlas Mountains in Morocco and western Algeria. The development of a steep gradient between a trough and a Saharan high along the Western Sahara and the western Mediterranean basin is a typical condition during which dust is rapidly transported toward the central Mediterranean. The aerosol optical depth at the beginning of the second dust outbreak (on 13th March, 2004) and the average over the period 10-15 March 2004 clearly show the severe dust outbreaks across the Atlantic and the Northern part of Italy: during this event the monitoring site at Mt. Cimone has found along the main axis of the dust plume, and recorded a concentration as high as 80 μg/SCM. Detailed analysis of the event is discussed and presented

Characteristic Scales for Turbulent Exchange Processes in a Real Urban Canopy

An experimental field campaign is designed to unveil mechanisms responsible for turbulent exchange processes when mechanical and thermal effects are entwined. The focus is an urban street canyon with a mean aspect ratio H/W of 1.65 in the business centre of a mid-size Italian city (H is the mean building height and W is the mean canyon width). The exchange processes can be characterized by time scales and time-scale ratios specific to either mechanical or thermal process. Time scales describe the mixing caused by momentum and heat exchange within different canyon layers, while their rates are surrogates of their efficacy. Given that homogeneous mixing does not always occur within the canyon, several time scales are estimated at different levels, showing that mechanical and thermal processes may both contribute to enhance mixing. By computing mechanical time scales, it is found that the fastest mixing occurs at the canyon rooftop level for perpendicular or oblique wind directions, while slow mixing occurs for parallel directions. Thermal processes are faster than the mechanical ones and are particularly efficient for perpendicular wind directions. By calculating the time-scale ratios, exchange processes are found to facilitate mixing for most wind directions and to regulate the pollutant-concentration variability in the canyon. This variability can be associated with the local-circulation regime, demarcated as thermally driven or inertially driven using a buoyancy parameter, i.e., the ratio between thermal and inertial forcings. Using this approach, a generalization of the results is proposed, enabling the extension of the current investigation to different street-canyon aspect ratios