841 research outputs found

    Seasonal changes in dry matter yield from Karst pastures as influenced by morphoclimatic features

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    Pastures are strongly affected by local environmental variables in terms of their species richness, plant composition and herbage production. A multi-site monitoring study was conducted over three years to investigate the influence of morphoclimatic factors on the seasonal variations in dry matter (DM) yield from Karst pastures. Seven sites located on the Italian and Slovenian Karst regions were investigated that differed in terms of their geological and geomorphological features, as well as their soil types. At each site, the daily DM yield (kg ha-1 d-1) was determined using Corral-Fenlon method which permits to simulate herbage utilization from grazing herds. The morphoclimatic features were also analysed, with the aim to evaluate the link between seasonal DM yield and geomorphological and environmental factors. Generalized non-linear mixed models were built to study the observed seasonal variations in DM yield, using day of the year (DOY), growing degree days (GDD), and cumulative rainfall. Furthermore, environmental descriptors were included in the model in order to evaluate their effects on DM yield. The seasonal variations in yield showed two growing periods (spring and late summer), which were described by Gaussian curves. For the spring growing period, the model improved when the interaction between soil granulometry and growing degree days corresponding to the curve peak was taken into account. This confirms the influence of soil type and air temperature on pasture yield. For the late summer growing period, the interaction between the sand classes and the number of rainy days from the beginning of the period to the peak of the curve improved the model. The curve parameters of our models are correlated with environmental descriptors depending on the lithology and particle size of soils. The results are essential for the optimization of pasture management and avoiding degradation due to over- or under-grazing

    Variazioni meteomarine recenti e climatologia dinamica nel bacino adriatico: primi risultati

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    Abstract Recent sea level variations are a key indicator of global climate change. Estimating sea-level rise is one of the most important scientific issues, with a potential large positive social impact. The Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC), underlines the importance of instrumental records to analyse recent sea-level changes. The relatively intense warming recorded throughout the latest 40 years - with widespread ice melting and relative glacial-hydro-isostatic rearrangement - has however induced global sea level rise ranging around 1.2-2.0 mm/yr. In the Mediterranean Sea, this value is significantly lower (approximately by 35%) than the global mean value. Likely, this is due to the Northern Atlantic Oscillation (NAO), inducing at the Adriatic latitudes an evident increase of atmospheric pressure and temperature, as well as of salinity variation; also taking into account the specific features of this almost closed shallow sea. However, relative sea level rise (RSLR) occurred along the entire shorelines of the Northern Adriatic Sea, locally interfering with land subsidence, both natural and man-induced, and eustasy. Their combined effect has produced relative ground settlements ranging from centimetres to meters. Aim of this study is to analyse the historic series of meteo-marine records for 12 measuring stations, belonging to the National Tidal Network organized by ISPRA, located between Trieste and Otranto in order both to verify trends in sea level variations and to identify the most significant storm events occurred from 2010 to 2015. Synoptic situations responsible for these intense events for each sector of the basin have been analysed too. Persistence of subtropical high pressure conditions alternated with higher frequency of cyclogenesis have been detected for almost every month on both the northern Adriatic basin and the medium and high Tyrrhenian; this most likely is due to the increase of sea surface temperatures: around at 0.8 °C in the last fifteen years. Keywords: climate change, rising average sea level, Adriatic Sea, cyclogenesis, storm surge

    A new early warning drought index for Ethiopia

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    Abstract This study investigates the occurrence of droughts in the Dire Dawa area of eastern Ethiopia. A new index based on the rainfall delay (Rd) with respect to the expected onset (and traditional) seeding time and other indices, i.e., the aridity index and the Z-score, alternatives to the Standard Precipitation Index (SPI), are used to test the validity of the new Rd index in identifying severe droughts extending back to 1955. Although only data of rain gauges located in the district of Dire Dawa were used, they proved, albeit with different accuracies, able to identify nation-wide droughts

    Analysis of recent meteorological configurations responsible for substantial snowfalls in the Trentine sector of the Adige valley bottom (eastern italian Alps).

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    Aim of this presentation is to analyse the synoptic conditions favourable to snowfall with more than 10 cm fresh snow cover in the bottom of the Trentine sector of the Adige Valley. Following the abundant and reiterated snowfalls in the study area during the 2005-2006 winter season and the many discomforts to the population and mainly to the road traffic, an accurate study of such events resulted necessary for a reliable forecast. The valley orientation in a NNE-SSW direction lets the Mediterranean warm-humid air masses to get in as far as the main headwater divide (Brenner Pass) and to make its climate relatively mild. Moreover, such humid air inflows bring mean annual precipitation of about 800-1000 mm that gradually decreses from the lower valley mouth to the main divide. The precipitation regime consists of rainfalls in spring and autumn whereas a strong absolute minimum occurs between December and Febraury when snowfalls are more likely on the valley floor. In fact, the vally is annually subjected to warm advection snowfalls, though infrequent and scarce, between November and mid April. The study area is about 80 km long with elevation ranging from 130 and 230 m a.s.l. All the snowfall events observed from 1980 to 2006 were analysed by using the data of the Civil Protection Authority of Trento Province, i.e. Trento Roncafort (194 n a.s.l.), Trento Laste (312 m a.s.l.), Rovereto (203 m a.s.l.) and Ala (197 m a.s.l.) meteo stations. Through the study and analysis of ground and at the 500 hPa geopotential meteo maps, satellite images, thermodynamic diagrams of the nearest sounding stations and the data of the nivometeorological stations, the synoptic types that characterised the snowfalls were studied and classified and a clusterisation was made. For each of the synoptic types defined the conditions for a quantification of the mean characteristic meteo parameters were anlysed in order to obtain a reliable forecast of intense snowfalls on the valley bottom

    Mass Mortality Event of Mediterranean Mussels (Mytilus galloprovincialis) in the Middle Adriatic: Potential Implications of the Climate Crisis for Marine Ecosystems

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    The effects of the climate crisis are affecting ecosystems at different scales and magnitudes. This paper focuses on a massive Mediterranean mussel die-off observed along the middle Italian Adriatic coast in the summer of 2022. We considered the possible environmental causes of this phenomenon and carried out a climatic analysis of the last decade. We performed field surveys in different locations along a 16 km coastal stretch from Martinsicuro (TE) in the south, to Grottammare (AP) in the north. The study area includes two marine Sites of Community Importance under the European Natura 2000 network. The die-off of the mussels was observed in practically all the natural mussel beds colonizing the study area. As sessile filter-feeding organisms inhabiting the intertidal zone, mussels are highly exposed to variations in environmental conditions such as temperature and nutrient load. We discuss the possible causes of this die-off, proposing that high temperature and the scarce availability of food acted simultaneously as stress factors, generating local unsustainable living conditions for this species

    SNOWFALL ANALYSIS OVER PENINSULAR ITALY IN RELATIONSHIP TO THE DIFFERENT TYPES OF SYNOPTIC CIRCULATION: FIRST RESULTS

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    The time series of snow data for a sample of Italian meteorological stations have been analyzed taking into account, for the time series, an acceptable continuity and quality of meteorological data. The data set is that of the Italian Meteorological Service (UGM), and refer to the period 1982–2004. The Slovenian station of Kredarica, located in the Julian Alps, has been added for convenience. The study is composed of two different parts: - Climatologic analysis of the snow parameters during the last 20 years. In particular, the height of the fresh snow and the number of days with permanence of snow at the ground have been analyzed. - Evidence of the synoptic situations in which snowfalls are observed with at least a thickness of 10 cm in at least a third of the total number of analyzed stations in Central, Southern and insular Ital

    Preliminary analysis of relationships between covid19 and climate, morphology, and urbanization in the lombardy region (Northern Italy)

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    The coronavirus disease 2019 (COVID-19) pandemic is the most severe global health and socioeconomic crisis of our time, and represents the greatest challenge faced by the world since the end of the Second World War. The academic literature indicates that climatic features, specifically temperature and absolute humidity, are very important factors affecting infectious pulmonary disease epidemics - such as severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS); however, the influence of climatic parameters on COVID-19 remains extremely controversial. The goal of this study is to individuate relationships between several climate parameters (temperature, relative humidity, accumulated precipitation, solar radiation, evaporation, and wind direction and intensity), local morphological parameters, and new daily positive swabs for COVID-19, which represents the only parameter that can be statistically used to quantify the pandemic. The daily deaths parameter was not considered, because it is not reliable, due to frequent administrative errors. Daily data on meteorological conditions and new cases of COVID-19 were collected for the Lombardy Region (Northern Italy) from 1 March, 2020 to 20 April, 2020. This region exhibited the largest rate of official deaths in the world, with a value of approximately 1700 per million on 30 June 2020. Moreover, the apparent lethality was approximately 17% in this area, mainly due to the considerable housing density and the extensive presence of industrial and craft areas. Both the Mann-Kendall test and multivariate statistical analysis showed that none of the considered climatic variables exhibited statistically significant relationships with the epidemiological evolution of COVID-19, at least during spring months in temperate subcontinental climate areas, with the exception of solar radiation, which was directly related and showed an otherwise low explained variability of approximately 20%. Furthermore, the average temperatures of two highly representative meteorological stations of Molise and Lucania (Southern Italy), the most weakly affected by the pandemic, were approximately 1.5 °C lower than those in Bergamo and Brescia (Lombardy), again confirming that a significant relationship between the increase in temperature and decrease in virulence from COVID-19 is not evident, at least in Italy

    Les droits disciplinaires des fonctions publiques : « unification », « harmonisation » ou « distanciation ». A propos de la loi du 26 avril 2016 relative à la déontologie et aux droits et obligations des fonctionnaires

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    The production of tt‾ , W+bb‾ and W+cc‾ is studied in the forward region of proton–proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98±0.02 fb−1 . The W bosons are reconstructed in the decays W→ℓν , where ℓ denotes muon or electron, while the b and c quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions.The production of ttt\overline{t}, W+bbW+b\overline{b} and W+ccW+c\overline{c} is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98 ±\pm 0.02 \mbox{fb}^{-1}. The WW bosons are reconstructed in the decays WνW\rightarrow\ell\nu, where \ell denotes muon or electron, while the bb and cc quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions

    LHCb upgrade software and computing : technical design report

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    This document reports the Research and Development activities that are carried out in the software and computing domains in view of the upgrade of the LHCb experiment. The implementation of a full software trigger implies major changes in the core software framework, in the event data model, and in the reconstruction algorithms. The increase of the data volumes for both real and simulated datasets requires a corresponding scaling of the distributed computing infrastructure. An implementation plan in both domains is presented, together with a risk assessment analysis
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