This application is made up by an observational module, that includes two different oceanographic instruments, the float and the glider, and a numerical module, the OPATM-BFM coupled model.

FLOAT

Argo profiling floats are autonomous instruments that drift freely with the currents and move up and down the water column at fixed intervals, typically every 5 or 10 days. The vertical motion is created by pumping fluid into (and out of) an external bladder to increase (decrease) the float volume and make it ascend (descend). During ascent, a CTD instrument measures temperature and conductivity, from which salinity is calculated. When at surface (typically during 6 hours), the float is located by, and transmits data to, the Argos system onboard polar-orbiting satellites, before it deflates its bladder and descends to its parking depth and repeats the cycle. A float is generally designed to perform ~150 cycles. The float data are transferred to the user (OGS) and to one of the Argo Data Assembly Centres (DAC) where they are processed and made available in NRT. http://poseidon.ogs.trieste.it/sire/medargo/active/index.html

GLIDER

The glider is an innovative Autonomous Underwater Vehicle (AUV), specifically designed to work in littoral areas (up to 200 m depth). It moves to specific locations and depths, occupying controlled spatial and temporal grids. It is equipped with several oceanographic sensors. Driven in a saw tooth profile, the glider samples the water column at regional scale. This instrument can be programmed to patrol for weeks at a time, surfacing to transmit the data to land while downloading new instructions at regular intervals, at a substantial cost savings compared to traditional surface ships. The communications to and from the Glider occur by means of the dedicated “Dock Server” machine. Each time the glider comes to the surface the Dock Server notifies users by e-mail (customizable) that specific glider events have occurred (i.e. establishing communications, status, aborting). Additionally, the glider sends to the Dock Server (not to the users) short binary files (*.sbd) containing the records of selected and customizable sensors (to reduce communication time). Matlab routines and stand-alone applications are used to convert, elaborate and plot the glider data. http://poseidon.ogs.trieste.it/sire/glider/

OPATM-BFM

The OPATM-BFM is a three-dimensional MPI parallel coupled eco-hydrodynamic model that has been developed at OGS in the framework of the MERSEA-IP EU FP6 project (www.mersea.eu.org/), launched in 2004 in order to develop a sustainable pan-European pre-operational forecasting system. The model, which connects the OPA Transport Model with the Biogeochemical Flux Model BFM, adopts the off-line coupling between the physics and the ecology, where the time integration of the transport-reaction biogeochemical equations is solved using the physical forcing fields (current velocity, wind speed, short wave radiation, etc.) externally supplied by the MFS model of the National Institute of Geophysics and Volcanology (INGV; Bologna, Italy). The model is presently embedded in a fully automatic, unsupervised, pre-operational procedure hosted at CINECA (Bologna, Italy) that provides 7-days analyses and 10-days forecasts of the biogeochemistry of the Mediterranean marine ecosystem on a weekly basis. The products delivered on the OGS website are maps of biogeochemical concentrations (chlorophyll, macronutrients, phytoplankton and bacterial productivity). http://poseidon.ogs.trieste.it/cgi-bin/opaopech/mersea

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