M3A system (2000–2005) – operation and maintenance

Abstract

Abstract. During the pilot phase of the Mediterranean Forecasting System (MFSPP) (2000 2003), a prototype observing system (Mediterranean Moored Multi-sensor Array -M3A) was designed, developed and operated in the Cretan Sea for continuous oceanographic measurements in real time. The main problems encountered were associated with biofouling, underwater and aerial communication and with the design of the surface buoy. In the second phase of the MFS project named Mediterranean Forecasting System Towards Environmental Predictions (MFSTEP) (2003)(2004)(2005), the aim was to solve those problems and to consolidate the M3A. For the minimisation of biofouling a pilot field study was performed and the techniques of bromine solution and copper shielding were evaluated. Additionally, the oligotrophy of the Aegean Sea dictated the need to ignore factory calibrations and to perform site-specific laboratory calibrations of the sensors. This procedure was proved necessary and produced calibration coefficients that gave results comparable to the measurements obtained with the laboratory analysis method. During the approximately five years of operation, there were 13 scheduled and 15 emergency visits, with a total duration of 65 days. The acquired experience through the maintenance program proved that the continuous observation of such a very important system with a relative low cost is feasible.

Data assimilation of depth-distributed satellite chlorophyll-α in two Mediterranean contrasting sites

“…The POSEIDON E1-M3A station (35.66N, 24.99E) is located approximately 24 nautical miles north of Heraklion, in the Cretan Sea ( Fig. 1) and it is the first multi-parametric station in the Eastern Mediterranean (Nittis et al, 2003;Petihakis et al, 2007). Although the station is These datasets included spatially averaged climatological vertical profiles of inorganic nutrients and Chl-α, downloaded from the OGS data server (Manca et al, 2004).…”

The role of hydrographic parameters, measured from a ship of opportunity, in bloom formation of Karenia mikimotoi in the English Channel

“…It is widely accepted that sensor measurements record only the fluorescent properties of seawater (and communities therein) and are not accurate values for chlorophyll-a concentrations (Falkowski & Kiefer, 1985). Accuracy may be improved by calibrating fluorometers in situ although the calibration will only hold as long as the phytoplankton community remains constant which is unlikely to be true over extended time periods (Petihakis et al, 2007).…”

The M3A multi-sensor buoy network of the Mediterranean Sea

“…It maintains brominated water that prevents the growth of phytoplankton inside the circuit and the sensors, in-between measurements. The two methods have been tested during a dedicated experiment in the Aegean Sea and have proved to offer an efficient anti-fouling protection for at least three months (Petihakis et al, 2007).…”