Freezing of the Venetian Lagoon since the 9th century A.D. in comparision to the climate of western Europe and England   总被引：2，自引：0，他引：2  

Dario Camuffo 《Climatic change》1987,10(1):43-66

In the first part of this study, typical of historical climatology, the various sources regarding freezing of the Venetian Lagoon since the 9th century A.D., are reported and discussed. The events are related, where possible, to teleconnections. Two synoptic patterns (weather type A: northerly and D: easterly) seem to have played an important role. After having discussed the dynamics of the icing processes, the problem of comparing the data is considered, as over the centuries many works were made on the Lagoon, in order to divert the major tributaries. In fact, the hydrological regime and the physical characteristic of the Lagoon environment were changed, so that the conditions necessary for freezing were no longer the same. The series was compared with the severe winters in westtern Europe and England, in order to reconstruct the past climate of the Mediterranean region and discuss the observed secular changes in the light of the widely accepted ideas of climatic variations. The comparison shows some differences: e.g. at Venice the Medieval Climatic Optimum with the occurrence of severe winters ended earlier and the Little Ice Age was broken by a milder interval.  相似文献   

A multiscale observational case study of an isolated tornadic supercell     

Dario B. Giaiotti  Fulvio Stel   《Atmospheric Research》2007,83(2-4):152-161

This work deals with the analysis of an isolated tornadic supercell thunderstorm that took place on the plain of Friuli Venezia Giulia (Italy) causing several damage. The analysis is performed using different kind of data, looking in the available information for possible signatures that could be helpful in the forecasting and nowcasting procedures. The analysis reveals that rather than a single cause for the tornadic storm development, there is an “interaction” of several effects. In particular, a favorable environment seems to be produced by the interplay between synoptic and mesoscale environments with a fundamental role played by orography. Radar data, in particular Doppler measurements, are fundamental to the recognition and interpretation of the events but in this particular case they could give little useful information for the forecasting and nowcasting procedures. The most robust signals of an environment prone to the onset of severe deep moist convection come from the thermal gradients at the ground and by the vertical profile analysis. The reason why the event took place in that specific place and not in others is still unknown.  相似文献   

Landslide detection and monitoring capability of boat-based mobile laser scanning along Dieppe coastal cliffs,Normandy     

Clément Michoud  Dario Carrea  Stéphane Costa  Marc-Henri Derron  Michel Jaboyedoff  Christophe Delacourt  Olivier Maquaire  Pauline Letortu  Robert Davidson 《Landslides》2015,12(2):403-418

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Randomized Tensor Decomposition for Large-Scale Data Assimilation Problems for Carbon Dioxide Sequestration     

Liu  Mingliang  Grana  Dario  Mukerji  Tapan 《Mathematical Geosciences》2022,54(7):1139-1163

Mathematical Geosciences - Data assimilation methods are commonly used to predict petrophysical properties of deep saline aquifers for carbon dioxide sequestration studies. However, data...  相似文献   

Deep‐sourced gas seepage and methane‐derived carbonates in the Northern Adriatic Sea          下载免费PDF全文

Federica Donda  Edy Forlin  Emiliano Gordini  Giuliana Panieri  Stefan Buenz  Valentina Volpi  Dario Civile  Laura De Santis 《Basin Research》2015,27(4):531-545

In the Northern Adriatic Sea, the occurrence of gas seepage and of unique rock outcrops has been widely documented. The genesis of these deposits has recently been ascribed to gas venting, leading to their classification as methane‐derived carbonates. However, the origin of seeping gas was not clearly constrained. Geophysical data collected in 2009 reveal that the gas‐enriched fluid vents are deeply rooted. In fact, the entire Plio‐Quaternary succession is characterized by widespread seismic anomalies represented by wipe‐out zones, and interpreted as gas chimneys. They commonly root at the base of the Pliocene sequence but also within the Palaeogene succession, where they appear to be associated to deep‐seated faults. We suggest that there is a structural control on chimney distribution. Chimneys originate and terminate at different stratigraphic levels; commonly they reach the seafloor, where authigenic carbonate deposits form locally. Gas analyses of some gas bubble streams just above the rock outcrops reveal that gas is composed mainly of methane. Geochemical analyses performed at four selected outcrop sites show that these deposits formed as a consequence of active gas venting. In particular, geochemical analyses indicate carbonate precipitation from microbial oxidation of methane‐rich fluids, although a straightforward correlation with the source depth of gas feeding the authigenic carbonates cannot yet be clearly defined.  相似文献   

Revisited Formulation and Applications of FFT Moving Average     

de Figueiredo  Leandro Passos  Grana  Dario  Le Ravalec  Mickaele 《Mathematical Geosciences》2020,52(6):801-816

Mathematical Geosciences - The fast Fourier transform-moving average (FFT-MA) is an efficient method for the generation of geostatistical simulations. The method relies on the calculation of a...  相似文献   

Merging active and passive data sets in traveltime tomography: The case study of Campi Flegrei caldera (Southern Italy)   总被引：1，自引：0，他引：1  

Jean Battaglia  Aldo Zollo  Jean Virieux  Dario Dello Iacono 《Geophysical Prospecting》2008,56(4):555-573

We propose a strategy for merging both active and passive data sets in linearized tomographic inversion. We illustrate this in the reconstruction of 3D images of a complex volcanic structure, the Campi Flegrei caldera, located in the vicinity of the city of Naples, southern Italy. The caldera is occasionally the site of significant unrests characterized by large ground uplifts and seismicity. The P and S velocity models of the caldera structure are obtained by a tomographic inversion based on travel times recorded during two distinct experiments. The first data set is composed of 606 earthquakes recorded in 1984 and the second set is composed of recordings for 1528 shots produced during the SERAPIS experiment in 2001. The tomographic inversion is performed using an improved method based on an accurate finite‐difference traveltime computation and a simultaneous inversion of both velocity models and earthquake locations. In order to determine the adequate inversion parameters and relative data weighting factors, we perform massive synthetic simulations allowing one to merge the two types of data optimally. The proper merging provides high resolution velocity models, which allow one to reliably retrieve velocity anomalies over a large part of the tomography area. The obtained images confirm the presence of a high P velocity ring in the southern part of the bay of Pozzuoli and extends its trace inland as compared to previous results. This annular anomaly represents the buried trace of the rim of the Campi Flegrei caldera. Its shape at 1.5 km depth is in good agreement with the location of hydrothermalized lava inferred by gravimetric data modelling. The Vp/Vs model confirms the presence of two characteristic features. At about 1 km depth a very high Vp/Vs anomaly is observed below the town of Pozzuoli and is interpreted as due to the presence of rocks that contain fluids in the liquid phase. A low Vp/Vs body extending at about 3–4 km depth below a large part of the caldera is interpreted as the top of formations that are enriched in gas under supercritical conditions.  相似文献   

Thermodynamic exchanges between the external boundary layer and the indoor microclimate at the Basilica of Santa Maria Maggiore, Rome, Italy: the problem of conservation of ancient works of art     

Dario Camuffo  Giovanni Sturaro  Antonio Valentino 《Boundary-Layer Meteorology》1999,92(2):243-262

The Basilica of Santa Maria Maggiore, Rome, is an example of how ancient buildings with thick walls lessen the impact of the external temperature and humidity variations. The external influence on the internal microclimate is studied in order to gather information on how the building exchanges heat and moisture. Correlations between outdoor and indoor values are found. The results are applied to the calculation of the condensation-evaporation cycles inside micropores due to the Kelvin effect, to assess their impact on works of arts placed inside and outside the Basilica. It was found that the building attenuation is not sufficient to avoid damage due to condensation-evaporation cycles on stones and plasters. Some suggestions are made in order to mitigate the temperature variations during the liturgical offices.  相似文献   

Geolithological and anthropogenic controls on the hydrochemistry of the Volturno river (Southern Italy)   总被引：1，自引：0，他引：1       下载免费PDF全文

Emilio Cuoco  Nicolò Colombani  Thomas H. Darrah  Micòl Mastrocicco  Dario Tedesco 《水文研究》2017,31(3):627-638

The present work aims to study the main chemical and physical water parameters in the upper and middle Volturno river catchment (southern Italy), between the Capo Volturno springs and the confluence with the Calore river. This study makes use of morphology, geolithology, tectonic, land use, and physico‐chemical (pH, electrical conductivity, redox potential, temperature, major ions, and ²²²Rn) data for the identification of the main sources of surface and groundwaters in the Volturno catchment and of their evolution and mixing both in base flow and peak flow conditions. The study was also performed to assess whether the alteration due to potential anthropogenic contamination may hamper the identification of natural “primitive” sources of surface waters, especially in the populated and farmed plains far from the river headwaters. Our data suggest that water chemistry of this stretch of the Volturno river is dominated mainly by lithology and, only marginally, by the intense exogenous activities and that this trend is appreciable in both base flow and peak flow conditions. The proposed simple geochemical approach based on easy‐to‐sample matrices and on cost‐effective standard methods is a valuable tool to address catchment functionality especially in upland areas, where complex geologic and structural settings, heterogeneous groundwater flow, and logistical issues are the rule rather than the exception. Because the upper and middle Volturno catchment is comparable with numerous valleys of the Mediterranean area, this study could be a reference for analogous applications.  相似文献   

A high temperature superconductor notch filter for the Sardinia Radio Telescope     

Pietro Bolli  Luca Cresci  Frederick Huang  Sergio Mariotti  Dario Panella 《Experimental Astronomy》2018,45(2):165-176

A High Temperature Superconductor filter operating in the C-band between 4200 and 5600 MHz has been developed for one of the radio astronomical receivers of the Sardinia Radio Telescope. The motivation was to attenuate an interference from a weather radar at 5640 MHz, whose power level exceeds the linear region of the first active stages of the receiver. A very sharp transition after the nominal maximum passband frequency is reached by combining a 6th order band-pass filter with a 6th order stop-band. This solution is competitive with an alternative layout based on a cascaded triplet filter. Three units of the filter have been measured with two different calibration approaches to investigate pros and cons of each, and data repeatability. The final performance figures of the filters are: ohmic losses of the order of 0.15–0.25 dB, matching better than ?15 dB, and ?30 dB attenuation at 5640 MHz. Finally, a more accurate model of the connection between external connector and microstrip shows a better agreement between simulations and experimental data.  相似文献