39 research outputs found
L’amplificazione del moto sismico negli studi di Microzonazione Sismica e nelle Norme Tecniche delle Costruzioni
Multi-sensor analysis of convective activity in central Italy during the HyMeX SOP 1.1
Abstract. A multi-sensor analysis of convective precipitation events that occurred in central Italy in autumn 2012 during the HyMeX (Hydrological cycle in the Mediterranean experiment) Special Observation Period (SOP) 1.1 is presented. Various microphysical properties of liquid and solid hydrometeors are examined to assess their relationship with lightning activity. The instrumentation used consisted of a C-band dual-polarization weather radar, a 2-D video disdrometer, and the LINET lightning network. Results of T-matrix simulation for graupel were used to (i) tune a fuzzy logic hydrometeor classification algorithm based on Liu and Chandrasekar (2000) for the detection of graupel from C-band dual-polarization radar measurements and (ii) to retrieve graupel ice water content. Graupel mass from radar measurements was related to lightning activity. Three significant case studies were analyzed and linear relations between the total mass of graupel and number of LINET strokes were found with different slopes depending on the nature of the convective event (such as updraft strength and freezing level height) and the radar observational geometry. A high coefficient of determination (R2 = 0.856) and a slope in agreement with satellite measurements and model results for one of the case studies (15 October 2012) were found. Results confirm that one of the key features in the electrical charging of convective clouds is the ice content, although it is not the only one. Parameters of the gamma raindrop size distribution measured by a 2-D video disdrometer revealed the transition from a convective to a stratiform regime. The raindrop size spectra measured by a 2-D video disdrometer were used to partition rain into stratiform and convective classes. These results are further analyzed in relation to radar measurements and to the number of strokes. Lightning activity was not always recorded when the precipitation regime was classified as convective rain. High statistical scores were found for relationships relating lightning activity to graupel aloft
Precipitation products from the hydrology SAF
Abstract. The EUMETSAT Satellite Application Facility on Support to Operational Hydrology and Water Management (H-SAF) was established by the EUMETSAT Council on 3 July 2005, starting activity on 1 September 2005. The Italian Meteorological Service serves as Leading Entity on behalf of twelve European member countries. H-SAF products include precipitation, soil moisture and snow parameters. Some products are based only on satellite observations, while other products are based on the assimilation of satellite measurements/products into numerical models. In addition to product development and generation, H-SAF includes a product validation program and a hydrological validation program that are coordinated, respectively, by the Italian Department of Civil Protection and by the Polish Institute of Meteorology and Water Management. The National Center of Aeronautical Meteorology and Climatology (CNMCA) of the Italian Air Force is responsible for operational product generation and dissemination. In this paper we describe the H-SAF precipitation algorithms and products, which have been developed by the Italian Institute of Atmospheric Sciences and Climate (in collaboration with the international community) and by CNMCA during the Development Phase (DP, 2005–2010) and the first Continuous Development and Operations Phase (CDOP-1, 2010–2012). The precipitation products are based on passive microwave measurements obtained from radiometers onboard different sun-synchronous low-Earth-orbiting satellites (especially, the SSM/I and SSMIS radiometers onboard DMSP satellites and the AMSU-A + AMSU-B/MHS radiometer suites onboard EPS-MetOp and NOAA-POES satellites), as well as on combined infrared/passive microwave measurements in which the passive microwave precipitation estimates are used in conjunction with SEVIRI images from the geostationary MSG satellite. Moreover, the H-SAF product generation and dissemination chain and independent product validation activities are described. Also, the H-SAF program and its associated activities that currently are being carried out or are planned to be performed within the second CDOP phase (CDOP-2, 2012–2017) are presented in some detail. Insofar as CDOP-2 is concerned, it is emphasized that all algorithms and processing schemes will be improved and enhanced so as to extend them to satellites that will be operational within this decade – particularly the geostationary Meteosat Third Generation satellites and the low-Earth-orbiting Core Observatory of the international Global Precipitation Measurement mission. Finally, the role of H-SAF within the international science and operations community is explained.</p
The validation service of the hydrological SAF geostationary and polar satellite precipitation products
Abstract. The development phase (DP) of the EUMETSAT Satellite Application Facility for Support to Operational Hydrology and Water Management (H-SAF) led to the design and implementation of several precipitation products, after 5 yr (2005–2010) of activity. Presently, five precipitation estimation algorithms based on data from passive microwave and infrared sensors, on board geostationary and sun-synchronous platforms, function in operational mode at the H-SAF hosting institute to provide near real-time precipitation products at different spatial and temporal resolutions. In order to evaluate the precipitation product accuracy, a validation activity has been established since the beginning of the project. A Precipitation Product Validation Group (PPVG) works in parallel with the development of the estimation algorithms with two aims: to provide the algorithm developers with indications to refine algorithms and products, and to evaluate the error structure to be associated with the operational products. In this paper, the framework of the PPVG is presented: (a) the characteristics of the ground reference data available to H-SAF (i.e. radar and rain gauge networks), (b) the agreed upon validation strategy settled among the eight European countries participating in the PPVG, and (c) the steps of the validation procedures. The quality of the reference data is discussed, and the efforts for its improvement are outlined, with special emphasis on the definition of a ground radar quality map and on the implementation of a suitable rain gauge interpolation algorithm. The work done during the H-SAF development phase has led the PPVG to converge into a common validation procedure among the members, taking advantage of the experience acquired by each one of them in the validation of H-SAF products. The methodology is presented here, indicating the main steps of the validation procedure (ground data quality control, spatial interpolation, up-scaling of radar data vs. satellite grid, statistical score evaluation, case study analysis). Finally, an overview of the results is presented, focusing on the monthly statistical indicators, referred to the satellite product performances over different seasons and areas
Mobility and Migrations in the Rural Areas of Mediterranean EU Countries
AbstractThis chapter focuses on the ambivalent nature of contemporary migrations in European rural areas. The growing presence of immigrants in these areas is a direct result of the restructuring of agriculture and global agri-food chains. Evidence indicates that while agricultural work and rural settings are decreasingly attractive to local populations, they represent a favourable environment to international newcomers, due to the higher chances to access livelihood resources. The non-visibility and informality that characterise rural settings and agricultural work arrangements provide on the one side opportunities for employment, while also fostering illegal labour practices and situations of harsh exploitation
Corpi da lavoro. Etnografia del lavoro a giornata nelle serre siciliane
This paper analyses the results of an ethnographic research conducted among migrant farmworkers employed inside greenhouses in South Eastern Sicily. In particular, it deals with the body considered at the same time as the object and the tool of the fieldwork research. By focussing on their experience of participant observation as tomato pickers, the authors reflect upon the positioning of their bodies inside the field and describe the negotiation of their femininities into a male workplace. Moreover, the article focuses on the effects produced on the workers’ bodies by day labour as well as on the embodied forms of adaptation and resistance. It explores the narrations of mental and physical disease and the different practices of “embellishment” of male and female workers as a body response to a degrading job
Fiducia, onestà, incertezza. Convenzioni e relazioni sociali nel lavoro quotidiano degli intermediari nel mercato ortofrutticolo di Vittoria / Trust, Honesty, Uncertainty. Conventions and Social Relations in Brokers' Daily Labour in the Fruit and Vegetable Market in Vittoria (Sicily)
The article aims at understanding the set of meanings, norms,
values and ties affecting the everyday work of different types of
brokers employed within a fruit and vegetable market. The case study
is represented by a market located in Vittoria, the centre of the socalled Transformed Littoral Strip, in South-Eastern Sicily. The local
agricultural district hosts several workplaces devoted to the production
and distribution of crops: seeds companies, nurseries, greenhouses,
packinghouses, and fruit and veg markets. The latter represents the field
of our ethnographic investigation that relied, in particular, on the technique
of shadowing, and on around 50 in-depth interviews. The article deals
with the everyday life of several actors (producers, agents and dealers)
and investigates their negotiations, their worries, their ties. In particular,
the contribution scrutinizes which behaviours are deemed legitimate and
which are stigmatized within the social space of the market, in order to
draw a picture of the moral economy and of the conventions circulating
in this setting. Through a number of ethnographic examples, the article
describes how the economic-regulative sphere is actually connected and
mutually constitutive with the moral-evaluative one
Abitare (ne)i luoghi di lavoro. Il caso dei braccianti rumeni nelle serre della provincia di Ragusa
This contribution deals with the overlapping between productive and reproductive
spaces concerning the situation of Romanian citizens working and living in the
Italian biggest greenhouses district, located in South-Eastern Sicily. In the last
few years, Romanian farmworkers have been asked to reside within or nearby
the agricultural companies, producing an arrangement that could be define
as a dormitory labor regime. This spacial location of the workforce allows the
employers to shrink the labor costs, although forcing migrants into a condition
of isolation and seclusion. Thanks to the data collected through an ethnographic
research (participant observation, shadowing, semi-structured interviews), the
article provides some reflection on these dynamics, analyzing mainly: (1) the
implications of the recruitment strategies opting for couples of workers; (2) the
processes of appropriation and re-signification of life and work spaces under
taken by migrant farmworkers
La mobilità come risorsa. Strategie individuali e forme di organizzazione dei lavoratori nella Fascia Costiera Trasformata
L’obiettivo di questo contributo è quello di raccontare il lavoro nella Fascia Trasformata soffermandoci, in particolare, sulle forme di azione, collettive e individuali, messe in campo da parte dei braccianti per rompere l’isolamento e destreggiarsi in un regime di vita e di lavoro altamente precari. Il tentativo è quello di partire dall’esperienza soggettiva dei e delle migranti di nazionalità rumena che generalmente trascorrono in questo territorio un periodo di tempo che va da pochi mesi a diversi anni, affrontando condizioni di lavoro faticose. Nondimeno questi lavoratori e lavoratrici si organizzano per negoziare il proprio salario, accedere ai servizi presenti sul territorio, stringere legami attraverso i quali vengono a conoscenza di posti di lavoro migliori dove essere assunti. Il loro ruolo è fondamentale, non solo per produrre l’’oro rosso’ che ha reso celebre la Fascia Trasformata in tutta Italia, ma anche per ridisegnare le campagne e le città del ragusano, in altre parole per ridisegnare dal basso gli scenari locali di un capitalismo a ‘rete’ su scala globale