The Mediterranean analysis and forecasting physical system for the Copernicus Marine Service: description and skill assessment

The Mediterranean Analysis and Forecasting System is a numerical ocean prediction system that operationally produces analyses and 10 days forecasts of the main physical parameters for the entire Mediterranean Sea and its Atlantic Ocean adjacent areas. The system is composed by the hydrodynamic model NEMO (Nucleus for European Modelling of the Ocean) 2-way coupled with the third-generation wave model WW3 (WaveWatchIII) and forced by ECMWF (European Centre for Medium-range Weather Forecasts) atmospheric fields. The forecast initial conditions are produced by a 3D variational data assimilation system which considers a daily assimilation cycle of Sea Level Anomaly, vertical profiles of Temperature and Salinity from ARGO and ship CTDs and heat flux corrections with satellite SST. The system has been recently upgraded in the framework of the Copernicus Marine Environment Monitoring Service (CMEMS) by increasing the grid resolution from 1/16 to 1/24 degree in the horizontal, thus becoming fully mesoscale resolving and from 72 to 141 vertical levels, by increasing the number of fresh water river inputs and by updating the data assimilation scheme. The model has a non-linear explicit free surface and the forecast is forced by surface pressure, interactive heat, momentum and water fluxes at the air-sea interface. The focus of this work is to present the latest modeling system upgrades and the related improvements achieved by showing the model skill assessment including comparison with independent (insitu coastal moorings) and quasi-independent (insitu vertical profiles and satellite) datasets.PublishedHalifax, Nova Scotia, Canada4A. Oceanografia e clim

Mediterranean Sea Analysis and Forecast (CMEMS MED-Currents 2016-2019)

INGVPublished4A. Oceanografia e clim

Mediterranean Sea Analysis and Forecast (CMEMS MED-Currents 2016-2019)

Copernicus Marine Environment Monitoring ServicePublished4A. Oceanografia e clim

A 1/24 degree resolution Mediterranean analysis and forecast modeling system for the Copernicus Marine Environment Monitoring Service

The Mediterranean Forecasting System (MFS) is a numerical ocean prediction system that operationally produces analyses, reanalyses and short-term forecasts of the main physical parameters for the entire Mediterranean Sea and its Atlantic Ocean adjacent areas. This work is specifically focused on the description and evaluation of the analysis and forecast modeling system that covers the analysis of the current situation and produces daily updates of the following 10 days forecast. The system has been recently upgraded in the framework of the Copernicus Marine Environment Monitoring Service (CMEMS) by increasing the grid resolution from 1/16o to 1/24o in the horizontal and from 72 to 141 vertical levels, by increasing the number of fresh water river inputs and by updating the data assimilation scheme. The model has a non-linear explicit free surface and it is forced by surface pressure, interactive heat, momentum and water fluxes at the air-sea interface. In order to validate the modeling system and to estimate the accuracy of the model products, a quality assessment is regularly performed including both pre-operational qualification and near real time (NRT) validation procedures. Pre-operational qualification activities focus on testing the improvements of the quality of the new system with respect to the previous version and relies on past simulation and historical data, while NRT validation activities aim at routinely and on-line providing the skill assessment of the model analysis and forecasts and relies on the NRT available observations. The focus of this work is to present the new operational modeling system and the skill assessment including comparison with independent (insitu coastal moorings) and quasi-independent (insitu vertical profiles and satellite) datasets.PublishedBergen, Norway3SR. AMBIENTE - Servizi e ricerca per la Societ

A 1/24° resolution Mediterranean physical analysis and forecasting system for the Copernicus Marine Environment Monitoring Service

This study describes a new model implementation for the Mediterranean Sea that has been achieved in the framework of the Copernicus Marine Environment Monitoring Service (CMEMS). The numerical ocean prediction system, that operationally produces analyses and forecasts of the main physical parameters for the entire Mediterranean Sea and its Atlantic Ocean adjacent areas, has been upgraded by increasing the grid resolution from 1/16o to 1/24o in the horizontal and from 72 to 141 unevenly spaced vertical levels, by increasing the number of fresh water river inputs and by updating the data assimilation scheme. The model has a non-linear explicit free surface and it is forced by surface pressure, interactive heat, momentum and water fluxes at the airsea interface. The focus of this work is to present the new modelling system which will become operational in the near future and the validation assessment including the comparison with an independent non assimilated dataset (coastal moorings) and quasi-independent (in situ vertical profiles and satellite) datasets. The results show that the higher resolution model is capable of representing most of the variability of the general circulation in the Mediterranean Sea, however some improvements need to be implemented in order to enhance the model ability in reproducing specific hydrodynamic features particularly the Sea Level Anomaly.PublishedBergen, Norway3SR. AMBIENTE - Servizi e ricerca per la Societ

Mediterranean monitoring and forecasting operational system for Copernicus Marine Service

The MEDiterranean Monitoring and Forecasting Center (Med-MFC) is part of the Copernicus Marine Environment Monitoring Service (CMEMS, http://marine.copernicus.eu/), provided on an operational mode by Mercator Ocean in agreement with the European Commission. Specifically, Med MFC system provides regular and systematic information about the physical state of the ocean and marine ecosystems for the Mediterranean Sea. The Med-MFC service started in May 2015 from the pre-operational system developed during the MyOcean projects, consolidating the understanding of regional Mediterranean Sea dynamics, from currents to biogeochemistry to waves, interfacing with local data collection networks and guaranteeing an efficient link with other Centers in Copernicus network. The Med-MFC products include analyses, 10 days forecasts and reanalysis, describing currents, temperature, salinity, sea level and pelagic biogeochemistry. Waves products will be available in MED-MFC version in 2017. The consortium, composed of INGV (Italy), HCMR (Greece) and OGS (Italy) and coordinated by the Euro-Mediterranean Centre on Climate Change (CMCC, Italy), performs advanced R&D activities and manages the service delivery. The Med-MFC infrastructure consists of 3 Production Units (PU), for Physics, Biogechemistry and Waves, a unique Dissemination Unit (DU) and Archiving Unit (AU) and Backup Units (BU) for all principal components, guaranteeing a resilient configuration of the service and providing and efficient and robust solution for the maintenance of the service and delivery. The Med-MFC includes also an evolution plan, both in terms of research and operational activities, oriented to increase the spatial resolution of products, to start wave products dissemination, to increase temporal extent of the reanalysis products and improving ocean physical modeling for delivering new products. The scientific activities carried out in 2015 concerned some improvements in the physical, biogeochemical and wave components of the system. Regarding the currents, new grid-point EOFs have been implemented in the Med-MFC assimilation system; the climatological CMAP precipitation was replaced by the ECMWF daily precipitation; reanalysis time-series have been increased by one year. Regarding the biogeochemistry, the main scientific achievement is related to the implementation of the carbon system in the Med-MFC biogeochemistry model system already available. The new model is able to reproduce the principal spatial patterns of the carbonate system variables in the Mediterranean Sea. Further, a key result consists of the calibration of the new variables (DIC and alkalinity), which serves to the estimation of the accuracy of the new products to be released in the next version of the system (i.e. pH and pCO2 at surface). Regarding the waves, the system has been validated against in-situ and satellite observations. For example, a very good agreement between model output and in-situ observations has been obtained at offshore and/or well-exposed wave buoys in the Mediterranean Sea.PublishedVienna3SR. AMBIENTE - Servizi e ricerca per la Societ

SeaConditions: a web and mobile service for safer professional and recreational activities in the Mediterranean Sea

Abstract. Reliable and timely information on the environmental conditions at sea is key to the safety of professional and recreational users as well as to the optimal execution of their activities. The possibility of users obtaining environmental information in due time and with adequate accuracy in the marine and coastal environment is defined as sea situational awareness (SSA). Without adequate information on the environmental meteorological and oceanographic conditions, users have a limited capacity to respond, which has led to loss of lives and to large environmental disasters with enormous consequent damage to the economy, society and ecosystems. Within the framework of the TESSA project, new SSA services for the Mediterranean Sea have been developed. In this paper we present SeaConditions, which is a web and mobile application for the provision of meteorological and oceanographic observation and forecasting products. Model forecasts and satellite products from operational services, such as ECMWF and CMEMS, can be visualized in SeaConditions. In addition, layers of information related to bathymetry, sea level and ocean-colour data (chl a and water transparency) are displayed. Ocean forecasts at high spatial resolutions are included in the version of SeaConditions presented here. SeaConditions provides a user-friendly experience with a fluid zoom capability, facilitating the appropriate display of data with different levels of detail. SeaConditions is a single point of access to interactive maps from different geophysical fields, providing high-quality information based on advanced oceanographic models. The SeaConditions services are available through both web and mobile applications. The web application is available at www.sea-conditions.com and is accessible and compatible with present-day browsers. Interoperability with GIS software is implemented. User feedback has been collected and taken into account in order to improve the service. The SeaConditions iOS and Android apps have been downloaded by more than 105 000 users to date (May 2016), and more than 100 000 users have visited the web version

Coherent structures of turbulence in wall-bounded turbulent flows

Dottorato di Ricerca in Ingegneria Idraulica per l’Ambiente e il Territorio, Ciclo XXII,a.a. 2011Direct Numerical Simulation (DNS) of a fully developed turbulent channel flow represents a powerful tool in turbulence research: it has been carried out to investigate the main characteristics of wall-bounded turbulence. It consists of solving numerically the Navier-Stokes equations with physically-consistent accuracy in space and time. The major difficulty in performing turbulence calculations at values of the Reynolds number of practical interest lies in the remarkable amount of computational resources required. Recent advances in high performance computing, especially related to hybrid architectures based on CPU/GPU, have completely changed this scenario, opening the field of High Performance Direct Numerical Simulation of turbulence (HPDNS), to which new and encouraging perspectives have been associated with the development of an advanced numerical methodology for studying in detail turbulence phenomena. The research activities related to the Ph. D. Program concerns the high performance direct numerical simulation of a wall-bounded turbulent flow in a plane channel with respect to the Reynolds number dependence in order to investigate coherent structures of turbulence in the wall region. The objectives of the research have been achieved by means the construction and the validation of DNS turbulent flow databases, that give a complete description of the turbulent flow. The Navier- Stokes equations that governs the flow of a three-dimensional, fully developed, incompressible and viscous fluid in a plane channel have been integrated and a computational code based on a mixed spectral-finite difference scheme has been implemented. In particular, a novel parallel implementation of the Navier-Stokes solver on GPU architectures have been proposed in order to perform simulations at high Reynolds numbers. In order to deal with large amount of data produced by the numerical simulation, statistical tools have been developed in order to verify the accuracy of the computational domain and describe the energetic budgets that govern the energy transfer mechanisms close to the wall. Flow visualization has been provided in order to identify and evaluate the temporal and morphological evolution coherent structures of turbulence in the wall region. The objectives of the research have been achieved by means the construction and the validation of DNS turbulent flow databases, that give a complete description of the turbulent flow. The Navier- Stokes equations that governs the flow of a three-dimensional, fully developed, incompressible and viscous fluid in a plane channel have been integrated and a computational code based on a mixed spectral-finite difference scheme has been implemented. In particular, a novel parallel implementation of the Navier-Stokes solver on GPU architectures have been proposed in order to perform simulations at high Reynolds numbers. In order to deal with large amount of data produced by the numerical simulation, statistical tools have been developed in order to verify the accuracy of the computational domain and describe the energetic budgets that govern the energy transfer mechanisms close to the wall. Flow visualization has been provided in order to identify and evaluate the temporal and morphological evolution threedimensional, fully developed, incompressible and viscous flow. The second part is devoted to the study of the numerical method for the integration of the Navier-Stokes equations. A mixed spectral-finite difference technique for the numerical integration of the governing equations is devised: Fourier decomposition in both streamwise and spanwise directions and finite difference method along the wall-normal direction are used, while a third-order Runge-Kutta algorithm coupled with the fractional-step method are used for time advancement and for satisfying the incompressibility constraint. A parallel computational codes has been developed for multicore architectures; furthermore, in order to simulate the turbulence phenomenon at high Reynolds numbers, a novel parallel computational model has been developed and implemented for hybrid CPU/GPU computing systems. The third part of the Ph. D. thesis concerns the analysis of numerical results, in order to evaluate the relationship between turbulence statistics, energy budgets and flow structures, allowing to increase the knowledge about wall-bounded turbulence for developing new predictive models and for the control of turbulenceUniversità degli Studi della Calabri

River runoff influences on the Central Mediterranean overturning circulation

t The role of riverine freshwater inflow on the Central Mediterranean Overturning Circulation (CMOC) was studied using a high-resolution ocean model with a complete distribution of rivers in the Adriatic and Ionian catchment areas. The impact of river runoff on the Adriatic and Ionian Sea basins was assessed by a twin experiment, with and without runoff, from 1999 to 2012. This study tries to show the connection between the Adriatic as a marginal sea containing the downwelling branch of the anti-estuarine CMOC and the large runoff occurring there. It is found that the multiannual CMOC is a persistent anti-estuarine structure with secondary estuarine cells that strengthen in years of large realistic river runoff. The CMOC is demonstrated to be controlled by wind forcing at least as much as by buoyancy fluxes. It is found that river runoff affects the CMOC strength, enhancing the amplitude of the secondary estuarine cells and reducing the intensity of the dominant anti-estuarine cell. A large river runoff can produce a positive buoyancy flux without switching off the antiestuarine CMOC cell, but a particularly low heat flux and wind work with normal river runoff can reverse it. Overall by comparing experiments with, without and with unrealistically augmented runoff we demonstrate that rivers affect the CMOC strength but they can never represent its dominant forcing mechanism and the potential role of river runoff has to be considered jointly with wind work and heat flux, as they largely contribute to the energy budget of the basin. Looking at the downwelling branch of the CMOC in the Adriatic basin, rivers are demonstrated to locally reduce the volume of Adriatic dense water formed in the Southern Adriatic Sea as a result of increased water stratification. The spreading of the Adriatic dense water into the Ionian abyss is affected as well: dense waters overflowing the Otranto Strait are less dense in a realistic runoff regime, with respect to no runoff experiment, and confined to a narrower band against the Italian shelf with less lateral spreading toward the Ionian Sea center. 1Published1675-17034A. Oceanografia e climaJCR Journa

Mediterranean Sea Analysis and Forecast (CMEMS MED-Currents 2016-2019)

The CMEMS Mediterranean Sea Analysis and Forecast system comprises a coupled wave-current system composed by an Ocean General Circulation Model based on NEMO v3.6 and a Wave Model based on WW3 v3.14 with a variational data assimilation scheme (OceanVar) for temperature and salinity vertical profiles and satellite SLA along track data. The model has a 1/24\u2dauniform horizontal grid resolution and 141 unevenly spaced vertical levels. It spans the time period 2016-2019 and it is operationally updated. This dataset refers to the Med-MFC Physical EAS4 system