The meteo-marine forecasting system of the IOI-Malta Operational Centre (University of Malta) consists of three main components:

IOI-MOC operates three models. These are:

* 1) ROSARIO-II Malta Shelf Marine Bulletins, * 2) Malta MARIA/ETA Atmospheric Forecasts, and * 3) MARIA/WAM Wave Forecasts.

The Malta Shelf ROSARIO-II hydrodynamical model is an eddy-resolving primitive equation sigma level shelf-scale numerical model. It is run at two spatial resolutions - at 1/64°x1/64° (ROSARIO-6420) and at 1/96°x1/96° (ROSARIO-9620). In both cases, the model is nested to the regional model with a grid ratio of 1:2. The model includes full thermohaline dynamics and adopts a turbulence scheme for the vertical mixing coefficients on the basis of the Princeton Ocean Model. It is implemented within the study area (from 13.80°E to 14.94°E and from 35.42°N to 37.21°N) with 115 grid points in latitude and 74 in longitude for the lower resolution and 110 grid points in latitude and 172 in longitude for a higher resolution version. The model has three open boundaries (on the West, South and East).

The numerical code used is based on an application of the Princeton Ocean Model, POM (Blumberg and Mellor, 1987). POM is a primitive equation, stratified and nonlinear numerical ocean model which utilises the Boussinesq approximation and hydrostatic equilibrium. It uses the free surface, potential temperature and salinity, the three orthogonal components of velocity, the turbulence kinetic energy and the turbulence macroscale as the prognostic variables. The model features include a split mode time step and a sigma-coordinate transformation for the vertical grid.

The bottom following sigma layers allow the model to represent accurately regions of high topographic variability. The horizontal grid uses curvilinear orthogonal coordinates and an “Arakawa C” differencing scheme. The Mellor and Yamada (1982) turbulence closure scheme is used to calculate the coefficients of vertical mixing of momentum, the vertical eddy viscosity and the eddy diffusivity of heat and salt. Density is calculated by an adaptation of the UNESCO equation of state revised by Mellor (1991).

The ROSARIO forecasts are re-initialized daily from the MFSTEP-Sicily Channel Regional Model (SCRM) daily averaged fields. The bullettins are issued daily and consist of 3-hourly averaged forecast fields for the following 3 and a half days 0 starting from 00:00 GMT on the current day D to 12:00 GMT of day D + 3. Forecast fields are centred at 1.5hr, 4.5hr, 7.5hr, 10.5hr, 13:5hr, 16.5hr, 19.5hr and 22.5hr GMT for each day.

Model outputs include 3h - average 2D fields of : Temperature, Salinity, Elevation and Total velocity

Colour maps and animations of sea temperature, salinity and velocity fields, and a user-friendly interface showing forecasted sea surface temperature and vertical temperature profiles at selected monitoring points close to important coastal spots are uploaded daily providing a marine forecasts around the Maltese Islands.

Rosario 6420:

[[http://www.capemalta.net/MFSTEP/results.html]]

Rosario 9620:

[[http://www.capemalta.net/ROSARIO9620/results.html]]

The ROSARIO outputs are produced as images, ASCII, and CF-NetCDF.

The data is available through THREDDS/OpenDAP located at:

[http://ioi.projects.um.edu.mt:8180/thredds]

Data may also be distributed by ftp through a secure connection to a dedicated file server. Access is reserved to licensed users only, who will be provided with a personal login and password.

Products are for the use of both commercial companies and public-research institutions. All data are provided under a non-transferable license. Data access for private companies is subject to the payment of a fee, which is calculated according to the type and volume of requested data and, if necessary, the data handling and re working.

The ROSARIO-II forecast fields in graphic form are available free of charge on [http://www.capemalta.net/MFSTEP/results.html] and [http://www.capemalta.net/ROSARIO9620/results.html]. Use of these forecasts are subject to copyright restrictions and due recognition and acknowledgement should be given by all users.

The Malta MARIA/ETA Atmospheric Forecasting systems has been setup with the purpose of operational numerical weather prediction in the area round the Maltese Islands. The system has been implemented as part of the WERMED activities with the support of Svetlana Music. It is based on the atmospheric limited area NCEP/Eta model (Janjic, 1984, Mesinger et al, 1988). Its main runtime components are the:

• data acquisition and pre-processing for preparation of boundary conditions and input fields
• model run at the computing centre of the PO-Unit
• post-processing and graphical presentation of model output
• scripts and procedures for automatic daily operation

The atmospheric forecasts are based on the Eta hydrostatic limited area grid point model with a “step-mountain” vertical coordinate system. The prognostic variables are temperature (T), wind (u,v components), specific humidity (q), surface pressure (ps) and turbulent kinetic energy (TKE). The downscaling of atmospheric conditions to the sub-regional scale is done by executing the model runs in two nesting steps with successively embedded model configurations down to a resolution of 1/24o (~ 5 Km) over the Central Mediterranean area, and with outputs every 3 hours.

The downscaling of atmospheric conditions to the subregional scale is done by executing the model runs in two successive steps with nested successively embedded model configurations. The first run is performed with the coarser resolution basin scale NCEP/Eta model (~32 km) over the whole Mediterranean region. This in turn provides detailed initial and boundary conditions to the second model with the higher resolution over the Central Mediterranean area. In the vertical, the basin scale model uses 32 levels from the ground up to 16 km. For the initial and boundary conditions the NCEP objective analysis gridded data are used, on a 1.25 deg horizontal grid increment, for 10 standard pressure levels(from 1000-100hPa). The basin scale forecast is run on a daily basis, starting from 12h GMT of the current day and produces a 72-hour forecast with 6-hour outputs. The second run is the high-resolution model (~5km) over the Central Mediterranean It also runs daily starting from 12hr GMT of the current daily and producing a 48-hour forecast with 3-hour outputs. The first model level is at 20m above the sea level. Prognostic variables are temperature (T), wind (u,v components), specific humidity (q), surface pressure (ps) and turbulent kinetic energy (TKE). The output parameters are: Geopotential, Temperature, Specific Humidity, wind components on 10 vertical standard pressure levels and surface parameter such as: 2m Temperature, 10m wind, 2m relative humidity, surface fluxes (latent, heat and radiative).

The Mediterranean basin scale forecast is run on a daily basis, starting from 12h GMT of the current day and produces a 72-hour forecast with 6-hour outputs and a horizontal resolution in space of about 40Km. The sub-regional higher resolution forecast also runs daily starting from 12hr GMT of the current daily and producing a 48-hour forecast with 3-hour outputs and a horizontal resolution of 1/6 Degrees.

The forecast is prepared in graphical form by a fully automated system before it is uploaded and presented daily for public viewing on the website:

http://www.capemalta.net/maria/pages/atmosforecast.html.

Users have the option of using two different forecast scales. The first covers the whole of the Mediterranean Basin, whilst the second consists of a higher resolution map over the Central Mediterranean area including the area around the Maltese Islands. The forecast fields consist of air temperature at 2m from the sea surface, atmospheric pressure at mean sea level, wind direction and magnitude at 10m height above the sea, and precipitation.

The Malta MARIA/ETA forecasts produce outputs in GRIB format with seperate files for the different resolutions.

The data may be obtained upon request via email. Any party interested in this data should redirect their demands to Prof. Aldo Drago (aldo.drago@um.edu.mt).

Products are for the use of both commercial companies and public-research institutions. All data are provided under a non-transferable license. Data access for private companies is subject to the payment of a fee, which is calculated according to the type and volume of requested data and, if necessary, the data handling and re working.

The MARIA/ETA forecast fields in graphic form are available free of charge on [http://www.capemalta.net/maria/basin/results.html] and [http://www.capemalta.net/maria/regional/results.html]. Use of these forecasts are subject to copyright restrictions and due recognition and acknowledgement should be given by all users.

The operational wave forecasting system at the IOI-Malta Operational Centre, University of Malta uses the 3rd generation spectral wave model WAM Cycle 4 (Gunther et al, 1992). Originally developed by Hasselmann, the WAM model has been later extended by the WAMDI group (The WAM Development and Implementation Group).

Within the WAM model, the basic equation is the wave action balance equation with a wave field spectrum in the two-dimensional frequency and direction space.

The energy equation is forced by a source term related to the near-surface atmospheric wind. The Model is forced by surface wind field from the MARIA/Eta atmospheric forecasting system, and runs once per day (starting at 12 UTC) to prepare a 72-hour forecast. Subsequent model runs are initialized using the sea state at analysis time, calculated from the previous run as a 24- hour forecast. The model is set-up as a 2-step nested system starting from a coarse grid covering the whole Mediterranean region at a resolution of 0.50º in both longitude and latitude direction. The intermediate grid domain is nested within the coarse grid and covers the Eastern Mediterranean region (east of 10º E) with grid resolution of 0.25º. A further high-resolution grid (resolution of 0.125º) over the Central Mediterranean is nested within the intermediate East Mediterranean grid.

The model set-up is based on the following run-time parameters: 30 frequencies (in the range from 0.041772 Hz to 0.66264), 24 directions (every 15 degree), 3 output grids, 4916 sea points, and 3-hour outputs. The time integration step is 1200 sec. The 2’ resolution bathymetry of Smith and Sandwell (1997) is used for producing the bathymetries. The original bathymetry data set is interpolated into related bathymetries for each of the 3 different output grids in the model set-up. The 6-hourly wind data used as input to the WAM model is generated by the ETA regional atmospheric model at the 0.5º resolution. The Mediterranean is treated as a closed basin, assuming no wave energy exchange with the Atlantic or the Black Sea. The output parameters from the WAM wave model are: significant wave height, mean wave direction and frequency of total sea, wind waves and swell.

The Mediterranean basin scale forecast is run on a daily basis, starting from 12h GMT of the current day and produces a 72-hour forecast with 6-hour outputs and a horizontal resolution in space of about 40Km. The sub-regional higher resolution forecast also runs daily starting from 12hr GMT of the current daily and producing a 48-hour forecast with 3-hour outputs and a horizontal resolution of 1/6 Degrees.

The forecast is prepared in graphical form by a fully automated system before it is uploaded and presented daily for public viewing on the website:

http://www.capemalta.net/maria/pages/waveforecast.html

Users have the option of using two different forecast scales. The first covers the whole of the Mediterranean Basin, whilst the second consists of a higher resolution map over the Central Mediterranean area including the area around the Maltese Islands. The forecast fields consist of Mean Wave Period, Peak Wave Period, Wind Speed and Direction, and Wave Speed and Direction.

The Malta MARIA/ETA forecasts produce outputs in GRIB format with seperate files for the different resolutions.

The data may be obtained upon request via email. Any party interested in this data should redirect their demands to Prof. Aldo Drago (aldo.drago@um.edu.mt).

Products are for the use of both commercial companies and public-research institutions. All data are provided under a non-transferable license. Data access for private companies is subject to the payment of a fee, which is calculated according to the type and volume of requested data and, if necessary, the data handling and re working.

The MARIA/WAM forecast fields in graphic form are available free of charge on [http://www.capemalta.net/maria/waveforecast/basin/results.html] and [http://www.capemalta.net/maria/waveforecast/regional/results.html]. Use of these forecasts are subject to copyright restrictions and due recognition and acknowledgement should be given by all users.