http://hdl.handle.net/2122/154 2013-05-18T20:21:28Z http://hdl.handle.net/2122/5741 Title: Skill assessment of the PELAGOS global ocean biogeochemistry model over the period 1980–2000 Authors: Vichi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Masina, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia Abstract: Global Ocean Biogeochemistry General Circulation Models are useful tools to study biogeochemical processes at global and large scales under current climate and future scenario conditions. The credibility of future estimates is however dependent on the model skill in capturing the observed multi-annual variability of firstly the mean bulk biogeochemical properties, and secondly the rates at which organic matter is processed within the food web. For this double purpose, the results of a multi-annual simulation of the global ocean biogeochemical model PELAGOS have been objectively compared with multi-variate observations from the last 20 years of the 20th century, both considering bulk variables and carbon production/consumption rates. Simulated net primary production (NPP) is comparable with satellite-derived estimates at the global scale and when compared with an independent data-set of in situ observations in the equatorial Pacific. The usage of objective skill indicators allowed us to demonstrate the importance of comparing like with like when considering carbon transformation processes. NPP scores improve substantially when in situ data are compared with modeled NPP which takes into account the excretion of freshly-produced dissolved organic carbon (DOC). It is thus recommended that DOC measurements be performed during in situ NPP measurements to quantify the actual production of organic carbon in the surface ocean. The chlorophyll bias in the Southern Ocean that affects this model as well as several others is linked to the inadequate representation of the mixed layer seasonal cycle in the region. A sensitivity experiment confirms that the artificial increase of mixed layer depths towards the observed values substantially reduces the bias. Our assessment results qualify the model for studies of carbon transformation in the surface ocean and metabolic balances. Within the limits of the model assumption and known biases, PELAGOS indicates a net heterotrophic balance especially in the more oligotrophic regions of the Atlantic during the boreal winter period. However, at the annual time scale and over the global ocean, the model suggests that the surface ocean is close to a weakly positive autotrophic balance in accordance with recent experimental findings and geochemical considerations. 2009-11-01T23:00:00Z http://hdl.handle.net/2122/5339 Title: Harbour water managment for port structures and sea bottom design, coast proximity navigation managment, water quality control. Authors: Faggioni, O.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Soldani, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Piangiamore, G. L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Ferrante, A.; Consiglio Superiore dei Lavori Pubblici, via Nomentana 2, Roma, 00161, Italy; Bencivenga, M.; Servizio Mareografico, Istituto Superiore per la Protezione e la Ricerca Ambientale, via Curtatone 3, Roma, 00185, Italy; Arena, G.; Servizio Mareografico, Istituto Superiore per la Protezione e la Ricerca Ambientale, via Curtatone 3, Roma, 00185, Italy; Nardone, G.; Servizio Mareografico, Istituto Superiore per la Protezione e la Ricerca Ambientale, via Curtatone 3, Roma, 00185, Italy Abstract: Tide is a sea level up-down water motion basically depending on three different phenomena: the Earth-Moon-Sun gravitational relationship, the water surface fluid reaction to atmospheric meteorological dynamic action and the Newtonian vertical adjustment of the sea surface due to atmospheric pressure variations. The first tide component (astro-tide) is periodic and well known in all points of the Earth surface; the second one is directly related to the meteorological phenomenon and then it is foreseeable; the Newtonian component, on the contrary, is not readily predictable by a general hydrostatic law, because the factor “J” that represents the Newtonian transfer (from the atmospheric weight to the consequent sea level) is variable in each harbour area. A statistical study and the related numerical data interpretation of the measurements performed in the Ports of Genoa, La Spezia, Marina di Carrara, Livorno, Piombino, Civitavecchia and Ravenna (belonging to the Italian Newtonian Meteotide Network) show port values of Jph (from 1.4-1.6 cm/hPa to > 2 cm/hPa, on the contrary of the off-shore areas where Jph is about 1 cm/hPa). This phenomenon (hydrobarometric tide wave) produces even double values of harbour sea level fluctuations amplitude in comparison to astronomic tide sea level oscillations, and is characterized by a wavelength from 8-12 h to same days and a 10-25 days/year as mean temporal occurrence in the Northern Tyrrhenian Sea. This is the most relevant ordinary risk factor for our ports activity and structures design. The present note shows a quantitative method to define the values of Jph factor for ports and its use in the Harbour WaterSide Management (HWSM) based on the joined use of barometers, hydrometers and clocks, the preliminary results related to the use of the gravimeters as hydrobarometric predictor in La Spezia Port and two examples of use of Jph factor in the port management: refloating of a landing ship and optimisation of a dock performance as pleasure boats mooring. 2008-10-06T22:00:00Z http://hdl.handle.net/2122/4504 Title: A process-oriented model study of equatorial Pacific phytoplankton: the role of iron supply and tropical instability waves Authors: Vichi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Masina, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Nencioli, F.; Università di Bologna e Università di Santa Barbara, US Abstract: The response of phytoplankton growth to iron supply and its modulation by large-scale circulation and tropical instability waves (TIWs) in the eastern equatorial Pacific has been investigated with an ocean biogeochemical model. This process study shows that iron can be efficiently advected from the New Guinea shelf through the Equatorial Undercurrent (EUC) to the eastern Pacific. The presence of a continental iron source is necessary for the maintenance of the observed subsurface iron maximum in the EUC core. In the eastern Pacific region, phytoplankton production is enhanced when additional iron is available in the EUC. Simulated phytoplankton variability is linked to TIWs activity, as revealed by a wavelet analysis of the total autotrophic carbon. The net local effect of the waves on phytoplankton can be either positive or negative depending on several factors. When the iron nutricline is sufficiently shallow to be reached by the wave vertical scale, the effect of the waves is to enhance iron availability in the euphotic zone leading to a net local increase of phytoplankton biomass. We therefore suggest that the local maxima of phytoplankton observed in moorings off the Equator in the eastern Pacific might be not only the result of concentration mechanisms, but also the result of an increase in local production sustained by advected iron. 2007-12-31T23:00:00Z http://hdl.handle.net/2122/4461 Title: Misure ambientali in mare aperto: sviluppo di tecnologie per l'acquisizione e l'analisi di dati meteo-mareografici misurati da una boa oceanografica in Mar Ligure Authors: Soldani, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Regazzoni, C. S.; DIBE - Università degli Studi di Genova, Genova; Bozzano, R.; CNR - ISSIA (Sezione di Genova), Genova; Faggioni, O.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Musso, M.; DIBE - Università degli Studi di Genova, Genova Editors: OGS / GNGTS Abstract: Obiettivo del presente lavoro è lo sviluppo di un metodo di analisi in grado di stimare i parametri fondamentali del moto ondoso, a partire dai dati acquisiti da tre altimetri acustici installati a bordo di una boa meteo-oceanografica operante in mare aperto. Il metodo di analisi sviluppato compie opportune operazioni di filtraggio sulle sequenze temporali delle misure effettuate dai tre altimetri, quindi, elaborando tali sequenze, fornisce le stime di alcuni parametri caratteristici del moto ondoso (tra cui l’altezza e la direzione di propagazione). I diversi tipi di filtraggio ed il metodo di stima sviluppati si basano sul calcolo di alcuni parametri statistici (tra cui media, mediana e deviazione standard) delle serie temporali di dati acquisiti, sulla conoscenza delle loro densità spettrali di potenza (calcolate mediante FFT), e sul calcolo delle funzioni di crosscorrelazione delle sequenze di dati prese a due a due. Il procedimento di stima realizzato è stato sperimentato su una notevole quantità di dati reali acquisiti in Mar Ligure tramite l’utilizzo della stazione di misura fissa su cui sono montati gli altimetri acustici, ed ha fornito risultati soddisfacenti per quanto riguarda affidabilità e precisione. Nell’ambito della valutazione delle prestazioni del sistema di acquisizione dati e del metodo di stima, i risultati ottenuti sono stati confrontati con misure provenienti da altri sensori a bordo della stazione e con stime analoghe effettuate a partire dai dati acquisiti da un’altra stazione di misura, operante anch’essa in Mar Ligure, ma dotata di strumentazione di altro tipo. 2004-12-13T23:00:00Z http://hdl.handle.net/2122/3434 Title: A process-oriented model study of equatorial Pacific phytoplankton: the role of iron supply and tropical instability waves Authors: Vichi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Nencioli, F.; Centro Interdipartimentale di Ricerca per le Scienze Ambientali, Ravenna, Italy; Masina, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia Abstract: The response of phytoplankton growth to iron supply and its modulation by large scale circulation and tropical instability waves (TIWs) in the eastern equatorial Pacific has been investigated with an ocean biogeochemistry model. This process study shows that iron can be efficiently advected from the New Guinea shelf through the Equatorial Undercurrent (EUC) to the eastern Pacific. In this region phytoplankton production is enhanced when an additional source of iron is applied in the New Guinea shelf and advected in the model by the EUC. In the eastern Pacific, phytoplankton variability is linked to TIWs activity, as revealed by a wavelet analysis of the total autotrophic carbon. The net local effect of the waves on phytoplankton can be either positive or negative depending on several fac- tors. In some cases the effect of the waves is to enhance iron availability in the euphotic zone leading to a net local increase of phytoplankton biomass, provided that the iron nu- tricline is sufficiently shallow to be reached by the wave vertical scale. In these cases it is also suggested that local maxima of phytoplankton observed in moorings off equator are sustained by advected iron and subsequent local production instead of being the result of concentration mechanisms. 2006-12-31T23:00:00Z http://hdl.handle.net/2122/2598 Title: The Adriatic Basin forecasting system Authors: Oddo, P.; Alma Mater Studiorum Università di Bologna, Centro Interdipartimentale per la Ricerca sulle Scienze Ambientali; Pinardi, N.; Alma Mater Studiorum Università di Bologna, Centro Interdipartimentale per la Ricerca sulle Scienze Ambientali; Zavatarelli, M.; Alma Mater Studiorum Università di Bologna, Centro Interdipartimentale per la Ricerca sulle Scienze Ambientali; Coluccelli, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia Abstract: A regional ocean forecasting system has been implemented in the framework of the ADRIatic sea integrated COastal areaS and river basin Management system Pilot Project (ADRICOSM). The system is composed of a 5 km horizontal resolution model and an observing system collecting coastal and open ocean hydrological data. The numerical model is based on the Princeton Ocean Model using a SMOLARKIEWICZ iterative advection scheme, interactive air-sea flux computation, Po and other Adriatic rivers flow rates and is one-way nested to a general circulation model of the Mediterranean Sea. In this study the data from the observing system are used only for model validation. The results of the first operational year are shown and the model performance has been assessed based on root mean square (RMS) criteria. 2005-12-31T23:00:00Z http://hdl.handle.net/2122/2597 Title: The ADRICOSM Pilot Project: a coastal and river basin prediction system for the Adriatic Sea Authors: Castellari, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Pinardi, N.; Università di Bologna, Corso di Scienze Ambientali; Coluccelli, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia Abstract: The ADRICOSM project was launched in October 2001, and ended in March 2005, with the main objective of demonstrating the feasibility of a near real time operational marine monitoring and forecasting system at the shelf and coastal scales, with connections to river basin runoff and coastal town sewer systems. The basic system consisted of an efficient network for the collection of marine data such as in situ temperature and salinity profiles and satellite sea surface temperature, a regional (AREG) and shelf scale modelling system, a data assimilation system and finally a coastal scale modelling system. Every week AREG releases 7 day marine forecasts at 5 km horizontal scales, which are used to nest other hydrodynamic models toward the coastal scale. Two shelf models (ASHELF-1 and ASHELF-2) at a 1.5 km horizontal scale were nested in AREG in order to simulate (and in the future to forecast) shelf scale oceanographic features. Another important aspect of ADRICOSM was the integration of the Cetina river (Croatia) and urban sewage monitoring/ modelling (Split, Croatia) systems with the shelf marine model. This integrated model system was used to simulate the dispersion of sewer discharges from the urban area in the coastal waters for water management performance studies. ADRICOSM is one of the first integrated land and marine waters operational oceanographic systems able to meet the urgent needs for reliable integrated coastal forecasts for the effective management of marine areas. 2005-12-31T23:00:00Z http://hdl.handle.net/2122/2587 Title: Spatial and temporal structure of Tropical Pacific interannual variability in 20th century coupled simulations Authors: Capotondi, A.; NOAA/Earth System Laboratory, CIRES/Climate Diagnostics Center,; Wittenberg, A.; Geophysical Fluid Dynamics Laboratory, Princeton, NJ, United States; Masina, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia Abstract: Tropical Pacific interannual variability is examined in nine state-of-the-art coupled climate models, and compared with observations and ocean analyses data sets, the primary focus being on the spatial structure and spectral characteristics of El Nin˜o-Southern Oscillation (ENSO). The spatial patterns of interannual sea surface temperature (SST) anomalies from the coupled models are characterized by maximum variations displaced from the coast of South America, and generally extending too far west with respect to observations. Thermocline variability is characterized by dominant modes that are qualitatively similar in all the models, and consistent with the ‘‘recharge oscillator’’ paradigm for ENSO. The meridional scale of the thermocline depth anomalies is generally narrower than observed, a result that can be related to the pattern of zonal wind stress perturbations in the central-western equatorial Pacific. The wind stress response to eastern equatorial Pacific SST anomalies in the models is narrower and displaced further west than observed. The meridional scale of the wind stress can affect the amount of warm water involved in the recharge/discharge of the equatorial thermocline, while the longitudinal location of the wind stress anomalies can influence the advection of the mean zonal temperature gradient by the anomalous zonal currents, a process that may favor the growth and longer duration of ENSO events when the wind stress perturbations are displaced eastwards. Thus, both discrepancies of the wind stress anomaly patterns in the coupled models with respect to observations (narrow meridional extent, and westward displacement along the equator) may be responsible for the ENSO timescale being shorter in the models than in observations. The examination of the leading advective processes in the SST tendency equation indicates that vertical advection of temperature anomalies tends to favor ENSO growth in all the CGCMs, but at a smaller rate than in observations. In some models it can also promote a phase transition. Longer periods tend to be associated with thermocline and advective feedbacks that are in phase with the SST anomalies, while advective tendencies that lead the SST anomalies by a quarter cycle favor ENSO transitions, thus leading to a shorter period. 2005-12-31T23:00:00Z http://hdl.handle.net/2122/2360 Title: Il primo OBS/H italiano per il monitoraggio e lo studio di faglie e vulcani sottomarini Authors: D'Anna, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Mangano, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; D'Anna, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Passafiume, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Speciale, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Amato, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia Abstract: L’Istituto Nazionale di Geofisica e Vulcanologia (INGV) ha testato con successo, nel luglio 2006, il primo Ocean Bottom Seismometer with Hydrophone (OBS/H) italiano (Fig. 1). Lo strumento, interamente progettato e realizzato all’Osservatorio di Gibilmanna del Centro Nazionale Terremoti, dopo aver superato i test in laboratorio, in camera iperbarica a 600 bar ed in mare a 3412 m di profondità, è stato deposto per 9 giorni (12-21/07/’06) sulla spianata sommitale del vulcano sottomarino Marsili a 790 m di profondità (Fig. 2) ed ha registrato 835 eventi tra cui un telesisma, 8 eventi regionali e circa 800 eventi vulcanici. 2005-12-31T23:00:00Z http://hdl.handle.net/2122/1178 Title: Predictability studies of coastal marine ecosystem behavior Authors: Vichi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia Abstract: The study presented in this thesis is principally meant to analyze the genericity of a deterministic, comprehensive marine ecosystem model in combination with various refined representations of hydrodynamical processes, and to evaluate the potential predictability skills of this combined modelling system with specific applications in two rather different coastal basins. This objective has been realized by first developing a modular coupling interface between the Princeton Ocean Model (POM) and the European Regional Seas Ecosystem Model (ERSEM), called High-Resolution OpenSESAME POM ERSEM (HiROPE). Secondly, this model framework, embedding a composite of 'complex' conceptual principles of the functioning of the main biogeochemical processes, has been applied to substantially different marine systems, the Baltic proper and the northern Adriatic Sea. The generic biological first principles of the ERSEM ecosystem model have been throughly controlled for consistency, and a suitable mathematical syntax has been defined in order to accomodate the various biogeochemical cycles of the resolved elements. The model has been specifically applied in the chosen basins with different temporal and spatial resolutions: a one-dimensional (vertical, 1D-V), climatological implementation in the northern Adriatic Sea; a 1D-V implementation in the Baltic proper with realistic forcing functions in the period 1979-1991 and a fully three-dimensional, high-frequency realistic implementation in the northern Adriatic Sea (October 1995). General conclusions are that the representation of hydrodynamical variability, the definition and resolution of boundary processes, the introduction of new source terms or the implementation of new biological state variables, affect the predictability of the system behavior more than the utilization of incomplete initial conditions of biological variables in a complex comprehensive ecosystem model. 2002-05-31T22:00:00Z