Four different Marine Rapid Environmental Assessment (MREA) procedures are compared with a focus ... more Four different Marine Rapid Environmental Assessment (MREA) procedures are compared with a focus on underwater acoustic performance. Co-located oceanographic-acoustic data were collected during the summer of 2015 in the Northwestern Mediterranean in the framework of a sea trial led by the NATO Centre for Maritime Research and Experimentation. The data were used to link MREA procedures and ocean-acoustic validation in a seamless framework. The MREA procedures consider Conductivity Temperature Depth (CTD) data, operational products from the Copernicus Marine Service, and two dynamical downscaling systems (with and without data assimilation). A portion of the oceanographic data are used for the assimilation procedure, and the remaining portion is withheld from the assimilation system for use as an independent verifying dataset. The accuracy of modelled acoustic properties is evaluated using the sound speed estimates from the different MREA methodologies as inputs to an acoustic model, ...
The observational part of the REP14-MED experiment was conducted in June 2014 in the Sardo-Balear... more The observational part of the REP14-MED experiment was conducted in June 2014 in the Sardo-Balearic Sea west of Sardinia Island (Western Mediterranean Sea). Two research vessels collected high-resolution oceanographic data by means of hydrographic casts, towed systems, and underway measurements. In addition, a vast amount of data was provided by a fleet of 11 gliders, time series were available from moored instruments, and information on Lagrangian flow patterns were obtained from surface drifters and one profiling float. The spatial resolution of the observations encompasses a spectrum over four orders of magnitude from <i>O</i>(10<sup>1</sup> m) to <i>O</i>(10<sup>5</sup> m), and the time series from the moored instruments cover a spectral range of five orders from <i>O</i>(10<sup>1</sup> s) to <i>O</i>(10<sup>6</sup> s). The objective of this article is to p...
This paper is intended as a short summary of 20 years of research on the Adriatic Sea carried out... more This paper is intended as a short summary of 20 years of research on the Adriatic Sea carried out by the Oceanography Department of IRPeM-CNR. The objective is to give a general overview of the sea and describe the environment in which anchovies live. The Adriatic Sea is a narrow basin elongated from north-west to south-east for about 800 km with a maximum width of 200 km at Bari and a minimum width of 100 km in front of Rimini. It communicates with the Ionian Sea through the Otranto Straits (74 km wide and 800 m sill depth). It is the most continental sub-basin of the Mediterranean, defined between two mountain chains: the Apennins to the west side and the Dinaric Alps and Balkans to the east. The Adriatic can be divided into three distinct sub-basins: Northern, Middle and Southern. Due to the geographical position, its orography and bathymetry, the Adriatic Sea hydrography is strongly influenced by meteorological conditions, particularly in the north. Climatologically, temperature...
Alongshore coastal currents and cyclonic gyres are the primary circulation features that connect ... more Alongshore coastal currents and cyclonic gyres are the primary circulation features that connect regions in the Adriatic Sea. Their strength is highly dependent on the wind, with Southeasterly Sirocco winds driving eastward cross-Adriatic transport from the Italian coasts and Northwesterly Mistral winds enhancing east-to-west transport. Results from the analysis show that Cross-Adriatic connection percentages were higher for east-to-west transport, with westward (eastward) transport observed mostly in the northern (southern) arms of the central and southern gyres.
Abstract Downscaling broadscale ocean model information to resolve the fine-scale swash-zone dyna... more Abstract Downscaling broadscale ocean model information to resolve the fine-scale swash-zone dynamics has a number of applications, such as improved resolution of coastal flood hazard drivers, modeling of sediment transport and seabed morphological evolution. A new method is presented, which enables wave-averaged models for the nearshore circulation to include short-wave induced swash zone dynamics that evolve at the wave group scale (i.e. averaged over the short waves). Such dynamics, which cannot be described, by construction through wave-averaged models, play a fundamental role in nearshore hydrodynamics and morphodynamics. The method is based on the implementation of a set of Shoreline Boundary Conditions (SBCs) in wave-averaged models. The chosen set of SBCs allows for proper computation of the short-wave properties at a mean shoreline ( x l ) taken as the envelope of the actual shoreline. The suitability of the approach is assessed through implementation of the SBCs into the Regional Ocean Modeling System (ROMS) coupled to a spectral wave model (InWave for IG waves and SWAN for wind waves). As the aim is to assess the viability of the approach, the SBCs are implemented only through a one-way coupling to ROMS (i.e. ROMS forcing the SBCs). Four different test cases – with constant, periodic and bichromatic offshore forcing – are run to assess the model performances. The main results of the analysis are: (a) the proposed SBCs can well reproduce the shoreline motion and swash zone dynamics in there for all chosen tests (RMSE and BIAS less than 20 % up to a cross-shore resolution of 4.0 m ( L 0 ∕ 3 or L 0 ∕ 5 )) and (b) implementation of the SBCs allows ROMS to accurately simulate the swash zone flows even at a resolution 40 times coarser than that needed by ROMS with its own wet–dry routine to properly describe the same flows. The latter result clearly demonstrates the major computational advantage of using the proposed SBCs. We also show that most of the swash zone dynamics is due to the mean flow (i.e. incoming Riemann variable) and the local (at x l ) wave height. However, especially in the case of bichromatic waves, the swash zone water volume content also seems to play a crucial role.
Introduction: Cohesive sediments play a key role in coastal, estuarine and riverine ecosystems by... more Introduction: Cohesive sediments play a key role in coastal, estuarine and riverine ecosystems by: 1) limiting the ability to remotely determine bathymetry, 2) transporting nutrients, metals and contaminants to the seafloor, and 3) altering the shear strength, erodibility and bearing capacity of nearshore sediment deposits. Clay minerals, colloidal metals and biopolymers form flocs, which accumulate in the nearshore regions. The floc dynamics is more complicated than that of non-cohesive sediments, because of the complex chemical composition. In particular, they settle to the seafloor faster than the single mineral grain, which is usually transported far offshore, due to elevated densities and lower hydrodynamic drag [1]. Flocs accumulate in seabed deposits of many navigable waterways (harbors, rivers, etc.), this often inhibiting ship traffic or requiring the seabed dredging (e.g. [1], [2]). Further, suspended sediment concentrations provide a primary mechanism for transport and de...
A hybrid variational-ensemble data assimilation scheme to estimate the vertical and horizontal pa... more A hybrid variational-ensemble data assimilation scheme to estimate the vertical and horizontal parts of the background-error covariance matrix for an ocean variational data assimilation system is presented and tested in a limited area ocean model implemented in the western Mediterranean Sea. An extensive dataset collected during the Recognized Environmental Picture Experiments conducted in June 2014 by the Centre for Maritime Research and Experimentation has been used for assimilation and validation. The hybrid scheme is used to both correct the systematic error introduced in the system from the external forcing (initial, lateral and surface open boundary conditions) and model parameterization and improve the representation of small scale errors in the Background Error Covariance matrix. An ensemble system is run off-line for further use in the hybrid scheme, generated through perturbation of assimilated observations. Results of four different experiments have been compared. The ref...
Anchovy, Engraulis encrasicolus, forms the basis of Italian small pelagic fisheries in the Adriat... more Anchovy, Engraulis encrasicolus, forms the basis of Italian small pelagic fisheries in the Adriatic Sea. The strong dependence of this stock on environmental factors and the consequent high variability makes the dynamics of this species particularly complicated to model. Weekly geo-referenced catch data of anchovy obtained by means of a Fishery Observing System (FOS) from 2005 to 2011 were referred to a 0.2 × 0.2 degree grid (about 20 km2) and associated with the environmental parameters calculated by a Regional Ocean Modelling System, AdriaROMS. Generalized Additive Mixed Models (GAMM) with and without random effects were used to identify a relationship between abundance in the catch and oceanographic conditions. The outcomes of models with no random effects, with random vessel effects and with the random vessel and random week-of-the-year effects were examined. The GAMM incorporating a random vessel and week-of-the-year effect were selected as the best model on the basis of the Akaike information criteria (AIC). This model indicated that catches (abundance) of anchovy in the Adriatic Sea correlate well with low temperatures, salinity fronts and sea surface height, and allowed the identification of areas where high concentrations of this species are most likely to occur. The results of this study demonstrate that GAMM are a useful tool to combine geo-referenced catch data with oceanographic variables and that the use of a mixed-model approach with spatial and temporal random effects is an effective way to depict the dynamics of marine species.
An understanding of environmental variability (stability/instability) is important to support ope... more An understanding of environmental variability (stability/instability) is important to support operational planning of expeditionary warfare and littoral operations, as well as for preparing the Recognized Environmental Picture (REP). Specifically, the identification of environmentally stable/unstable areas helps the planning of maritime operations, increasing their likelihood of success. The purpose of the paper is to describe a methodology to form and interpret an initial spatial-temporal variability characterization of maritime areas from Remote Sensing (RS) and Numerical Ocean Model (NOM) data. As a case study, the analysis of the sea surface tem- perature (SST) in the Black Sea from historical time-series of RS imagery and NOM data is considered. The results of the analysis are validated with in situ measurements from moorings. Identification of gaps of geospatial information is also done in this study. The analysis is focused on monthly spatial-temporal variability of the SST, generating stability maps displaying the geospatial distribution of environmentally stable/unstable areas along a year. The results show how the proposed methodology captures the temporal variability of the SST in the Black Sea, being compared with in situ measurements, and provides useful information for the identification of environmentally stable/unstable areas. The results show a general agreement in the variability with both RS and NOM data, when RS imagery may be used for the present analysis, i.e. when low cloud coverage is given. This paper demonstrates that when RS imagery gaps are not negligible (e.g. due to high cloud occurrence in winter season), these gaps could be filled with NOM data.
Four different Marine Rapid Environmental Assessment (MREA) procedures are compared with a focus ... more Four different Marine Rapid Environmental Assessment (MREA) procedures are compared with a focus on underwater acoustic performance. Co-located oceanographic-acoustic data were collected during the summer of 2015 in the Northwestern Mediterranean in the framework of a sea trial led by the NATO Centre for Maritime Research and Experimentation. The data were used to link MREA procedures and ocean-acoustic validation in a seamless framework. The MREA procedures consider Conductivity Temperature Depth (CTD) data, operational products from the Copernicus Marine Service, and two dynamical downscaling systems (with and without data assimilation). A portion of the oceanographic data are used for the assimilation procedure, and the remaining portion is withheld from the assimilation system for use as an independent verifying dataset. The accuracy of modelled acoustic properties is evaluated using the sound speed estimates from the different MREA methodologies as inputs to an acoustic model, ...
The observational part of the REP14-MED experiment was conducted in June 2014 in the Sardo-Balear... more The observational part of the REP14-MED experiment was conducted in June 2014 in the Sardo-Balearic Sea west of Sardinia Island (Western Mediterranean Sea). Two research vessels collected high-resolution oceanographic data by means of hydrographic casts, towed systems, and underway measurements. In addition, a vast amount of data was provided by a fleet of 11 gliders, time series were available from moored instruments, and information on Lagrangian flow patterns were obtained from surface drifters and one profiling float. The spatial resolution of the observations encompasses a spectrum over four orders of magnitude from <i>O</i>(10<sup>1</sup> m) to <i>O</i>(10<sup>5</sup> m), and the time series from the moored instruments cover a spectral range of five orders from <i>O</i>(10<sup>1</sup> s) to <i>O</i>(10<sup>6</sup> s). The objective of this article is to p...
This paper is intended as a short summary of 20 years of research on the Adriatic Sea carried out... more This paper is intended as a short summary of 20 years of research on the Adriatic Sea carried out by the Oceanography Department of IRPeM-CNR. The objective is to give a general overview of the sea and describe the environment in which anchovies live. The Adriatic Sea is a narrow basin elongated from north-west to south-east for about 800 km with a maximum width of 200 km at Bari and a minimum width of 100 km in front of Rimini. It communicates with the Ionian Sea through the Otranto Straits (74 km wide and 800 m sill depth). It is the most continental sub-basin of the Mediterranean, defined between two mountain chains: the Apennins to the west side and the Dinaric Alps and Balkans to the east. The Adriatic can be divided into three distinct sub-basins: Northern, Middle and Southern. Due to the geographical position, its orography and bathymetry, the Adriatic Sea hydrography is strongly influenced by meteorological conditions, particularly in the north. Climatologically, temperature...
Alongshore coastal currents and cyclonic gyres are the primary circulation features that connect ... more Alongshore coastal currents and cyclonic gyres are the primary circulation features that connect regions in the Adriatic Sea. Their strength is highly dependent on the wind, with Southeasterly Sirocco winds driving eastward cross-Adriatic transport from the Italian coasts and Northwesterly Mistral winds enhancing east-to-west transport. Results from the analysis show that Cross-Adriatic connection percentages were higher for east-to-west transport, with westward (eastward) transport observed mostly in the northern (southern) arms of the central and southern gyres.
Abstract Downscaling broadscale ocean model information to resolve the fine-scale swash-zone dyna... more Abstract Downscaling broadscale ocean model information to resolve the fine-scale swash-zone dynamics has a number of applications, such as improved resolution of coastal flood hazard drivers, modeling of sediment transport and seabed morphological evolution. A new method is presented, which enables wave-averaged models for the nearshore circulation to include short-wave induced swash zone dynamics that evolve at the wave group scale (i.e. averaged over the short waves). Such dynamics, which cannot be described, by construction through wave-averaged models, play a fundamental role in nearshore hydrodynamics and morphodynamics. The method is based on the implementation of a set of Shoreline Boundary Conditions (SBCs) in wave-averaged models. The chosen set of SBCs allows for proper computation of the short-wave properties at a mean shoreline ( x l ) taken as the envelope of the actual shoreline. The suitability of the approach is assessed through implementation of the SBCs into the Regional Ocean Modeling System (ROMS) coupled to a spectral wave model (InWave for IG waves and SWAN for wind waves). As the aim is to assess the viability of the approach, the SBCs are implemented only through a one-way coupling to ROMS (i.e. ROMS forcing the SBCs). Four different test cases – with constant, periodic and bichromatic offshore forcing – are run to assess the model performances. The main results of the analysis are: (a) the proposed SBCs can well reproduce the shoreline motion and swash zone dynamics in there for all chosen tests (RMSE and BIAS less than 20 % up to a cross-shore resolution of 4.0 m ( L 0 ∕ 3 or L 0 ∕ 5 )) and (b) implementation of the SBCs allows ROMS to accurately simulate the swash zone flows even at a resolution 40 times coarser than that needed by ROMS with its own wet–dry routine to properly describe the same flows. The latter result clearly demonstrates the major computational advantage of using the proposed SBCs. We also show that most of the swash zone dynamics is due to the mean flow (i.e. incoming Riemann variable) and the local (at x l ) wave height. However, especially in the case of bichromatic waves, the swash zone water volume content also seems to play a crucial role.
Introduction: Cohesive sediments play a key role in coastal, estuarine and riverine ecosystems by... more Introduction: Cohesive sediments play a key role in coastal, estuarine and riverine ecosystems by: 1) limiting the ability to remotely determine bathymetry, 2) transporting nutrients, metals and contaminants to the seafloor, and 3) altering the shear strength, erodibility and bearing capacity of nearshore sediment deposits. Clay minerals, colloidal metals and biopolymers form flocs, which accumulate in the nearshore regions. The floc dynamics is more complicated than that of non-cohesive sediments, because of the complex chemical composition. In particular, they settle to the seafloor faster than the single mineral grain, which is usually transported far offshore, due to elevated densities and lower hydrodynamic drag [1]. Flocs accumulate in seabed deposits of many navigable waterways (harbors, rivers, etc.), this often inhibiting ship traffic or requiring the seabed dredging (e.g. [1], [2]). Further, suspended sediment concentrations provide a primary mechanism for transport and de...
A hybrid variational-ensemble data assimilation scheme to estimate the vertical and horizontal pa... more A hybrid variational-ensemble data assimilation scheme to estimate the vertical and horizontal parts of the background-error covariance matrix for an ocean variational data assimilation system is presented and tested in a limited area ocean model implemented in the western Mediterranean Sea. An extensive dataset collected during the Recognized Environmental Picture Experiments conducted in June 2014 by the Centre for Maritime Research and Experimentation has been used for assimilation and validation. The hybrid scheme is used to both correct the systematic error introduced in the system from the external forcing (initial, lateral and surface open boundary conditions) and model parameterization and improve the representation of small scale errors in the Background Error Covariance matrix. An ensemble system is run off-line for further use in the hybrid scheme, generated through perturbation of assimilated observations. Results of four different experiments have been compared. The ref...
Anchovy, Engraulis encrasicolus, forms the basis of Italian small pelagic fisheries in the Adriat... more Anchovy, Engraulis encrasicolus, forms the basis of Italian small pelagic fisheries in the Adriatic Sea. The strong dependence of this stock on environmental factors and the consequent high variability makes the dynamics of this species particularly complicated to model. Weekly geo-referenced catch data of anchovy obtained by means of a Fishery Observing System (FOS) from 2005 to 2011 were referred to a 0.2 × 0.2 degree grid (about 20 km2) and associated with the environmental parameters calculated by a Regional Ocean Modelling System, AdriaROMS. Generalized Additive Mixed Models (GAMM) with and without random effects were used to identify a relationship between abundance in the catch and oceanographic conditions. The outcomes of models with no random effects, with random vessel effects and with the random vessel and random week-of-the-year effects were examined. The GAMM incorporating a random vessel and week-of-the-year effect were selected as the best model on the basis of the Akaike information criteria (AIC). This model indicated that catches (abundance) of anchovy in the Adriatic Sea correlate well with low temperatures, salinity fronts and sea surface height, and allowed the identification of areas where high concentrations of this species are most likely to occur. The results of this study demonstrate that GAMM are a useful tool to combine geo-referenced catch data with oceanographic variables and that the use of a mixed-model approach with spatial and temporal random effects is an effective way to depict the dynamics of marine species.
An understanding of environmental variability (stability/instability) is important to support ope... more An understanding of environmental variability (stability/instability) is important to support operational planning of expeditionary warfare and littoral operations, as well as for preparing the Recognized Environmental Picture (REP). Specifically, the identification of environmentally stable/unstable areas helps the planning of maritime operations, increasing their likelihood of success. The purpose of the paper is to describe a methodology to form and interpret an initial spatial-temporal variability characterization of maritime areas from Remote Sensing (RS) and Numerical Ocean Model (NOM) data. As a case study, the analysis of the sea surface tem- perature (SST) in the Black Sea from historical time-series of RS imagery and NOM data is considered. The results of the analysis are validated with in situ measurements from moorings. Identification of gaps of geospatial information is also done in this study. The analysis is focused on monthly spatial-temporal variability of the SST, generating stability maps displaying the geospatial distribution of environmentally stable/unstable areas along a year. The results show how the proposed methodology captures the temporal variability of the SST in the Black Sea, being compared with in situ measurements, and provides useful information for the identification of environmentally stable/unstable areas. The results show a general agreement in the variability with both RS and NOM data, when RS imagery may be used for the present analysis, i.e. when low cloud coverage is given. This paper demonstrates that when RS imagery gaps are not negligible (e.g. due to high cloud occurrence in winter season), these gaps could be filled with NOM data.
Uploads
Papers by Aniello Russo