Consorzio LAMMA

Sesto Fiorentino, Italy

Consorzio LAMMA

Sesto Fiorentino, Italy
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Brandini C.,Consorzio LaMMA | Brandini C.,CNR Institute for Biometeorology | Taddei S.,Consorzio LaMMA | Doronzo B.,Consorzio LaMMA | And 9 more authors.
Ocean Dynamics | Year: 2017

The hydrodynamics of coastal areas is characterized by the interaction among phenomena occurring at different spatial and temporal scales, such as the interaction of a large-scale ocean current with the local bathymetry and coastline, and local forcing conditions. In order to take into account all relevant phenomena, the study of the hydrodynamics of coastal zones requires a high-spatial and temporal resolution for both observations and simulation of local currents. This resolution can be obtained by using X-band radar, which allows simultaneous measurement of waves and currents in a range of 1–3 miles from the coastline, as well as high-resolution numerical models implemented in the area and configured through multiple nesting techniques in order to reach resolutions comparable to such coastal observations. Such an integrated monitoring system was implemented at the Isola del Giglio in 2012, after the accident of the Costa Concordia ship. Results can be used as a cross-validation of data produced independently by radar observations and numerical models. In addition, results give some important insights on the dynamics of the coastal boundary layer, both for what concerns the attenuation in the profile of the depth-averaged velocities which typically occur in turbulent boundary layers, as well as for the production, detachment and evolution of vorticity produced by the interaction of large-scale ocean currents with the coastline and the subsequent time evolution of such boundary layer. This transition between large-scale regional currents and the coastal boundary layer is often neglected in regional forecasting systems, but it has an important role in the ocean turbulence processes. © 2017 Springer-Verlag GmbH Germany

Lazzara L.,University of Florence | Marchese C.,University of Florence | Massi L.,University of Florence | Nuccio C.,University of Florence | And 4 more authors.
Italian Journal of Remote Sensing / Rivista Italiana di Telerilevamento | Year: 2010

The annual cycle of pelagic primary production (PP) from ocean colour is analysed in a transition area between Ligurian and Tyrrhenian waters, where a general oligo-mesotrophic status is seasonally modified by anthropic impact near the Tuscany coast. Based on the common ecological features six different zones were delimited. Remote sensing data from different satellites (Meteosat, Aqua) were used as input in a primary production model. The daily production of the entire area was computed on pixel by pixel basis (4×4 km) using a modified GIS software. Overwhelming importance of oceanic bloom and high spatial variance of PP (90 ±54 gC m -2 y r -1) show that remote sensed data can allow a better estimation of carbon budget even in optically complex waters.

Argenti G.,University of Florence | Bottai L.,Consorzio LaMMA | Chiesi M.,CNR Institute for Biometeorology | Maselli F.,CNR Institute for Biometeorology | And 2 more authors.
Italian Journal of Remote Sensing / Rivista Italiana di Telerilevamento | Year: 2011

The paper shows some operational techniques for the characterisation and mapping of pastoral resources in mountain areas. The utility of multispectral images was evaluated to produce thematic cartography of the studied pastures and to determine their pastoral value, a useful parameter for management purposes. Data collected by the multispectral ASTER sensor, with a 15 m spatial resolution in the VISNIR, 30 m in the SWIR, and 90 m in TIR, and the MODIS sensor, with a daily temporal step and a 250 m spatial resolution, were used. The images are classified using a maximum likelihood algorithm, while multivariate locally calibrated regression is applied to extend the pastoral value over the whole area. Results show a low capability of the satellite images in discriminating the different pasture vegetation types, whereas the assessment of pastoral value produces more promising achievements (r = 0.647;, RMSE = 6.99).

Massi L.,University of Florence | Santini C.,CNR Institute for Biometeorology | Pieri M.,Consorzio LaMMa | Nuccio C.,University of Florence | Maselli F.,University of Florence
Italian Journal of Remote Sensing / Rivista Italiana di Telerilevamento | Year: 2011

MODIS data have been widely used for the study of marine waters and particularly for the estimation of chlorophyll concentration [CHL]. The [CHL] retrieval algorithms which are applied to MODIS imagery show various degrees of accuracy depending on the presence of Case 1 and Case 2 waters (C1W and C2W). The current paper presents the adaptation of a recently proposed algorithm based on Spectral Angle Mapping (SAM) to characterize water types using MODIS data. The algorithm is applied to 26 MODIS images taken over the Western Mediterranean basin from 2003 to 2009. The value of a SAM indicator of proximity to Case 1 waters is first assessed towards in situ measurements collected during the same period. The results confirm that the fuzzy categorization into C1-C2W can be used to guide the application of different algorithms. In this way, the accuracy of [CHL] estimation is decidedly enhanced both in oceanic and coastal areas.

Natali F.,University of Florence | Cecchi L.,University of Florence | Torrigiani Malaspina T.,Consorzio LAMMA | Barbano F.,University of Florence | Orlandini S.,University of Florence
Aerobiologia | Year: 2013

The aim of this study was to assess the current aerobiological situation and to investigate the influence of the hot and dry summer 2003 on pollen season (onset, end and duration of the pollen season, peak pollen day and value, total seasonal amount of pollen grains) of herbaceous family as Poaceae, Urticaceae and Compositeae. Heat wave of 2003 influenced the phenology of the main pollen families in Tuscany: the high temperatures occurred during 2003 affected pollen season of different family with different responses. This study confirms the role that the climate has on the flora species and in particular on herbaceous species phenology and the high variability of the pollination among different places, during extreme events. In general, high spring temperature induces an advance of the flowering period and a release of higher pollen quantity of Urticaceae and Poaceae; however, exceptional weather conditions (i.e.; summer 2003) could exert an opposite effect, resulting in an impairment of flowering of Urticaceae during autumn. Compositeae species produced a low amount of pollen in 2003, even if the peak value was higher than the average in some stations. © 2013 Springer Science+Business Media Dordrecht.

Melani S.,CNR Institute for Biometeorology | Pasqui M.,CNR Institute for Biometeorology | Guarnieri F.,CNR Institute for Biometeorology | Antonini A.,Consorzio LAMMA | And 2 more authors.
Atmospheric Research | Year: 2010

Instantaneous rainfall intensities retrieved by a multi-sensor precipitation estimation algorithm based on the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) onboard Meteosat and on the Special Sensor Microwave Imager (SSM/I) data are used to investigate the dynamics and phenomenology associated with the African monsoon regime. A 5-year (2004-2008) climatology during the warm season (June-August) of coherent precipitation patterns is presented with emphasis on the intraseasonal and interannual variability of the tropical northern African Monsoon for the investigation of the longitudinal distribution of rainfall and the zonal component of motion. The coherence and phase speed of rain streaks are also quantified by means of a two-dimensional autocorrelation analysis to derive the zonal-span and the duration properties of the identified rain systems. The periodicity of the precipitating episodes is finally investigated through harmonic analysis performed in different longitudinal bands of the studied domain.Rainfall episodes tend to initiate in the lee of steep topography (maxima in correspondence of the Ethiopian highlands), consistently with the thermal heating forcing from elevated terrain. Such an organized convection consists of coherent sequences of precipitation episodes, which span an average distance of about 460. km and last about 10. h. The diurnal cycle of summer precipitation is characterised by afternoon and early evening maxima located mainly downwind of the major mountain chains, as also the spectral analysis has clearly highlighted. © 2010 Elsevier B.V.

Oberto E.,ARPA Piemonte | Milelli M.,ARPA Piemonte | Pasi F.,Consorzio LAMMA | Gozzini B.,CNR Institute for Biometeorology
Natural Hazards and Earth System Sciences | Year: 2012

The demand for verification of numerical models is still very high, especially for what concerns the operational Quantitative Precipitation Forecast (QPF) used, among others, for evaluating the issuing of warnings to the population. In this study, a comparative verification of the QPF, predicted by two operational Limited Area Models (LAMs) for the Italian territory is presented: COSMO-I7 (developed in the framework of the COSMO Consortium) and WRF-NMM (developed at NOAA-NCEP). The observational dataset is the precipitation recorded by the high-resolution non-GTS rain gauges network of the National Civil Protection Department (NCPD) over two years (2007-2008). Observed and forecasted precipitation have been treated as areal quantity (areal average of the values accumulated in 6 and 24 h periods) over the 102 "warning areas", defined by the NCPD both for administrative and hydrological purposes. Statistics are presented through a series of conventional indices (BIAS, POD and POFD) and, in addition, the Extreme Dependency Score (EDS) and the Base Rate (BS or 1-BS) have been used for keeping into account the vanishing of the indices as the events become rare. Results for long-period verification (the whole 2 yr) with increasing thresholds, seasonal trend (3 months period), diurnal error cycle and error maps, are presented. Results indicate that WRF has a general tendency of QPF overestimation for low thresholds and underestimation for higher ones, while COSMO-I7 tends to overestimate for all thresholds. Both models show a seasonal trend, with a bigger overestimation during summer and spring, while during autumn and winter the models tend to be more accurate. © 2012 Author(s).

Doronzo B.,Consorzio LaMMA | Doronzo B.,CNR Institute for Biometeorology | Taddei S.,Consorzio LaMMA | Brandini C.,Consorzio LaMMA | And 3 more authors.
Ocean Dynamics | Year: 2015

As shown in the literature, ocean surface circulation can be estimated from sequential satellite imagery by using the maximum cross-correlation (MCC) technique. This approach is very promising since it offers the potential to acquire synoptic-scale coverage of the surface currents on a quasi-continuous temporal basis. However, MCC has also many limits due, for example, to cloud cover or the assumption that Sea Surface Temperature (SST) or other surface parameters from satellite imagery are considered as conservative passive tracers. Also, since MCC can detect only advective flows, it might not work properly in shallow water, where local heating and cooling, upwelling and other small-scale processes have a strong influence. Another limitation of the MCC technique is the impossibility of detecting currents moving along surface temperature fronts. The accuracy and reliability of MCC can be analysed by comparing the estimated velocities with those measured by in situ instrumentation, but the low number of experimental measurements does not allow a systematic statistical study of the potentials and limitations of the method. Instead, an extensive analysis of these features can be done by applying the MCC to synthetic imagery obtained from a realistic numerical ocean model that takes into account most physical phenomena. In this paper a multi-window (MW-) MCC technique is proposed, and its application to synthetic imagery obtained by a regional high-resolution implementation of the Regional Ocean Modeling System (ROMS) is discussed. An application of the MW-MCC algorithm to a real case and a comparison with experimental measurements are then shown. © 2015, Springer-Verlag Berlin Heidelberg.

Melani S.,Consorzio LaMMA | Melani S.,CNR Institute for Biometeorology | Pasi F.,Consorzio LaMMA | Pasi F.,CNR Institute for Biometeorology | And 4 more authors.
Atmospheric Research | Year: 2013

Long-lasting, deep convective systems (DCS) occurring in the Mediterranean basin have been investigated for the 2007-2010. years using geostationary Meteosat Second Generation (MSG) satellite data, supported by the European Centre for Medium-Range Weather Forecasts (ECMWF) analyses and severe weather reports recorded by the European Severe Weather Database (ESWD). The spatial and seasonal variability of DCS occurrence have been investigated, as well as the most favourable synoptic precursors for their initiation. The analysis has shown the existence of some preferential areas of DCS genesis, mainly located in the western (i.e., around Balearic Islands) and central (i.e., Ionic and Tyrrhenian seas) Mediterranean, where these systems develop and grow preferentially in fall (i.e., September and October). The analysis of a selected set of Synoptic Precursors (SPs) has shown how the totality of the identified cases has occurred downstream a mid-tropospheric (500hPa) disturbance (trough or cut-off) within a southerly flow, with high values of θe (at 850hPa) and precipitable water. Moreover, the approaching of an upper level tropopause dynamical anomaly coupled with a local maximum of upper and low level horizontal wind speed, seems to play a very important role in triggering convection. Finally, a careful crosscheck of the detected cases with the ESWD reports has allowed to investigate the severity of these systems, as they often affect population and produce significant damages. This study has to be considered a necessary step towards the development of a larger climatologic database of long-lasting, deep convective events occurring in the Mediterranean sea, as well as the definition of a specific conceptual model based on synoptic precursors, having the long-term issue of setting up an objective procedure to support regional meteorological services in early decisions and accurate nowcasting. © 2012 Elsevier B.V.

Bottai L.,Consorzio LaMMA | Arcidiaco L.,Consorzio LaMMA | Chiesi M.,CNR Institute of Neuroscience | Maselli F.,CNR Institute of Neuroscience
Journal of Applied Remote Sensing | Year: 2013

A single-tree identification method has been applied to light detection and ranging (LiDAR) data acquired over a protected coastal area in Tuscany (San Rossore Regional Park, Central Italy). The method, which is based on the computation of the convergence index from the LiDAR tree-height image, is capable of identifying individual pine trees in densely populated stands. The main features of each pine tree (height and crown size) are also estimated, which allows the final prediction of stem volume. The accuracy of the stem volume estimates is first assessed through a comparison with the ground measurements of a recent forest inventory of the park [San Rossore Forest Inventory (SRFI)]. This test indicates that stem volume is predicted with moderate accuracy at stand level (r around 0.65). The stem volume estimates are then used to drive a modeling strategy which, on the basis of remotely sensed and ancillary data, is capable of predicting stem volume current annual increment (CAI). A final accuracy assessment indicates that the use of LiDAR stem volumes in place of the SRFI measurements only slightly deteriorates the quality of the obtained stand CAI estimates. © 2013 SPIE.

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