Analysis of Summer Ozone Observations at a High Mountain Site in Central Italy (Campo Imperatore, 2388 m a.s.l.)

Tropospheric ozone (O₃) is an important atmospheric pollutant and climate forcer. The Mediterranean basin is a hot-spot region in terms of short-term O₃ distribution, with frequent episodes of high tropospheric O₃, especially during summer. To improve the characterisation of summer O₃ variability in the Mediterranean area, during the period 6–27 August 2009 an experimental campaign was conducted at Campo Imperatore, Mt Portella (CMP), a high mountain site (2,388 m a.s.l.) located in the central Italian Apennines. As deduced from analysis of atmospheric circulation, the measurement site was significantly affected by air masses originating over the Mediterranean basin, which affected the measurement site for 32 % of the time. Analysis of average values and diurnal and day-to-day variability revealed that CMP O₃ observations (average value 60.0 ± 5.1 ppbv) were comparable with measurements at other European mountain stations, indicating a prevalent effect of meteorological conditions and atmospheric transport on the synoptic scale. In fact, only a small “reverse” diurnal variation typically characterises diurnal O₃ variability because of local thermal wind circulation, which sporadically favours transport of air masses rich in O₃ from the foothill regions. Statistical analysis of five-day back-trajectory ensembles indicates that synoptic-scale air-mass transport from the Mediterranean Sea usually results in decreasing O₃ concentrations at CMP, whereas the highest hourly O₃ values are mostly associated with air masses from central continental Europe, eastern Europe, and northern Italy. High O₃ concentrations are also related to downward air-mass transport from higher altitudes. Comparison of in-situ O₃ variability with tropospheric O₃ satellite-based measurements reveals similar features of the two data sets. Together with the results from back-trajectory analysis, this indicates that CMP measurements might usefully improve characterisation of broad-scale O₃ variability over the central Mediterranean basin.     

Analysis of Multitemporal NDVI Data for Crop Yield Forecasting in the Sahel

Abstract

Recent investigations demonstrated that inter‐year NOAA‐AVHRR NDVI variations at the middle of the rainy season can provide information on annual crop yields in Sahelian countries. This line of research is presently extended to the consideration of multitemporal NDVI data for several years (1986-1991) pre‐processed by a proven methodology. The investigation was conducted using NDVI and crop yield data from the sahelian sub‐districts of Niger. The results confirm that geographically standardized NDVI data are efficient for crop yield forecasting, but notable differences exist in this prediction capability depending on the beginning of the season. Late beginnings of the growing (rainy) season (after the end of June) allow optimum forecasting only after mid‐August, while early beginnings lead to anticipate the forecasting capability but also to decrease its accuracy. The importance of these findings in the context of an early warning system is finally discussed.     

Modelling the spatial allocation of second-generation feedstock (lignocellulosic crops) in Europe

This paper presents a modelling approach for the spatial allocation of second-generation feedstock (lignocellulosic crops) under a reference policy scenario in European Union of 28 Member State (EU-28). The land-use modelling platform (LUMP) was used in order to simulate the land-use changes from 2010 to 2050. Within the LUMP, the land demand for these lignocellulosic energy crops was derived from the Common Agricultural Policy Regionalised Impact analysis model. Suitability maps were generated for two main energy crop groups: herbaceous and woody lignocellulosic crops, using multicriteria analysis techniques. Biophysical factors (climate, soil properties and topographical aspects), natural and artificial constraints and location-specific land categories were defined as relevant components within the platform. A sensitivity analysis determined the most influential factors to be temperature, precipitation, length of growing period and number of frost-free days. The results of the modelling exercise in the LUMP reflect the significant renewable energy contribution from energy crops in EU-28, which was estimated to be between 2.3 EJ/year (in 2020) and 6.3 EJ/year (in 2050), accounting for 2.3% and 9.6% of total energy consumption in the EU-28. The results of the allocation were aggregated at regional level to analyse trends. Regions with considerably high demand were identified in Germany, the United Kingdom and Poland.     

Physically-based prediction of the maximum corner displacement magnification of one-storey eccentric systems

This paper gives a new insight into the linear dynamic behavior of one-storey eccentric systems, with particular attention devoted to provide a comprehensive physically-based formulation of the maximum corner displacement magnification, which involves three contributions (translational response, torsional response and their combination). It is shown that the largest magnifications, which mainly occur for the class of torsionally-flexible systems, are due to the translational contribution which is caused by the shift of the fundamental period of the eccentric system with respect to that of the equivalent not-eccentric system. A simplified method for the estimation of the maximum corner displacement under seismic excitation, based on the physical properties of the eccentric system, is finally proposed.     

LITHOPHILE ELEMENTS IN INDIVIDUAL CHONDRULES OF THE H-4 MAFRA CHONDRITE

Bulk and trace lithophilic elements (Al, Ca, Fe, Mn, Ti, Cr, Sr, V and Zn) have been determined in individual chondrules and in other constituents of the H-4 Mafra chondrite by means of flameless A.A. microanalysis. Twenty-four large sized (> 1 mg) chondrules, composite samples of minor-sized (0.1 and 0.2 mg) chondrules and fine-grained “interchondrular” material have been examined. Data on the large-sized chondrules exhibit large compositional variations among cosmochemically coherent groups of elements. A weak anti-correlation was found between the geochemically coherent refractory V and volatile Zn. A possible mass-composition relationship is suggested by the apparent concentration of lithophile high-temperature condensing elements (Ca, Al, Ti) in the minor-sized chondrules. Compositional features tend to support the hypothesis that chondrules originate from a large number of precursor components constituting a distinct grain population in the solar nebula. Melting through a sudden heating of random mixtures of these precursor grains was possibly followed by further condensation of volatiles and accretion.     

Stochastic energy analysis of seismic isolated bridges

In this paper, a parametric stochastic analysis of isolated bridge is proposed with the aim to assess isolation performance and to investigate effects of energetic influence on protection efficiency. The analysis has been carried out in terms of two stochastic parameters of pear-deck maximum displacement and hysteretic energy response, of which a qualitative trend has been observed.Isolated bridge is described by a simple two degree of freedom (TDoF) Bouc–Wen hysteretic model, which has been introduced for its intrinsic ability in reproducing a wide range of real devices behavior. With the aim of taking into consideration intrinsic stochastic nature of seismic events, the ground motion and the structural response have been described by random vibration approach. Results obtained show that protection achieved by shifting structural natural period and reducing input energy by devices dissipation have counteracting effects if related to deck lateral displacement.     

Middle to Late Holocene glacial variations, periglacial processes and alluvial sedimentation on the higher Apennine massifs (Italy)

The major climatic variations that have affected the summit slopes of the higher Apennine massifs in the last 6000 yr are shown in alternating layers of organic matter-rich soils and alluvial, glacial and periglacial sediments. The burial of the soils, triggered by environmental-climatic variations, took place in several phases. For the last 3000 yr chronological correlations can be drawn between phases of glacial advance, scree and alluvial sedimentation and development of periglacial features. During some periods, the slopes were covered by vegetation up to 2700 m and beyond, while in other phases the same slopes were subject to glacial advances and periglacial processes, and alluvial sediments were deposited on the high plateaus. Around 5740-5590, 1560-1370 and 1300-970 cal yr B.P., organic matter-rich soils formed on slopes currently subject to periglacial and glacial processes; the mean annual temperature must therefore have been higher than at present. Furthermore, on the basis of the variations in the elevation of the lower limit reached by gelifraction, it can be concluded that the oscillations in the minimum winter temperatures could have ranged between 3.0°C lower (ca. 790-150 cal yr B.P.) and 1.2°C higher (ca. 5740-5590 cal yr B.P.) than present minimum winter temperatures. During the last 3000 yr the cold phases recorded by the Calderone Glacier advance in the Apennines essentially match basically the phases of glacial advance in the Alps.     

North Atlantic Oscillation – Concepts And Studies

This paper aims to provide a comprehensive review of previous studies and concepts concerning the North Atlantic Oscillation. The North Atlantic Oscillation (NAO) and its recent homologue, the Arctic Oscillation/Northern Hemisphere annular mode (AO/NAM), are the most prominent modes of variability in the Northern Hemisphere winter climate. The NAO teleconnection is characterised by a meridional displacement of atmospheric mass over the North Atlantic area. Its state is usually expressed by the standardised air pressure difference between the Azores High and the Iceland Low. ThisNAO index is a measure of the strength of the westerly flow (positive with strong westerlies, and vice versa). Together with the El Niño/Southern Oscillation (ENSO) phenomenon, the NAO is a major source of seasonal to interdecadal variability in the global atmosphere. On interannual and shorter time scales, the NAO dynamics can be explained as a purely internal mode of variability of the atmospheric circulation. Interdecadal variability maybe influenced, however, by ocean and sea-ice processes.     

Seismic risk in historical centers

In the first part the paper outlines the current conceptions relevant to seismic risk for constructions in urban centres analysing seismic hazard, vulnerability and exposure. In the second part there are some details about the vulnerability assessment of ordinary buildings, and about the differences that arise when monumental or historical buildings are in question. Then the concept of seismic scenario is given (third part), so that the specific question of seismic vulnerability of historical centres may be treated (part four), presenting an appropriate methodology recently proposed by the author. Finally part five presents an introduction to the theme of risk mitigation for historical centres and monuments, a very difficult question, where the two aspects of preservation and seismic safety must be considered together.