State of the art of the E2M3A † M. Gačić, G. Gelsi, F. Arena, M. Burca, L. Perini, D. Sorgo *F. Gasparoni, F. Zanon ¶ G. Civitarese, V. Ibello G. Manzella Athens, December 2004 Ogs †, Tecnomare *, Ismar ¶, Enea

year 2003  05/03-10/03 buoy tests in Trieste harbor year 2004 January buoy transferred to Bari  Feb 16 to buoy installed at site and operative (only meteo and CT) Aug 06  Apr integration work (to reach MFSTEP configuration) in Bari harbor  Sep 18buoy installed at site  Sep 19 MFSTEP-TOP started  Sep 25 last daily message indicates failure of some sensors and anomalous position; mission stopped, buoy put in “idle mode” waiting maintenance intervention,  Oct 17 buoy drifted 2 miles towards NW due to the action of a strong Scirocco Wind  Oct 18recovering of the E2M3A 8 miles NW apart from the original mooring position and towed to Bari Harbor Main events

Some Pre-TOP Results

Mission started 19/9 at 8h CTD chain failure on 24/9 10h Meteo station failure on 24/9 23h (reason still unknown) In the subsequent hours, the buoy changes position (reason still unknown) Mission stopped 25/9 at 7h all the basic functionalities of the data acquisition and control system are maintained (the buoy is periodically interrogated from Tecnomare) some days later a fishing boat found the buoy still moored and the CTD chain in good status, apart the inductive cable broken maintenance intervention is being organised MFSTEP TOP mission events

25/9 1:00 25/9 7:00 Stop mission 19/9 8:00 Start mission 15/10 21:00 Buoy position (19/9 – 15/10)

Data acquisition

W i n d D a t a Speed Direction

temperature conductivity

Status parameters current from photovoltaic panels battery pack voltage

The system is able to produce two five-depth profiles per day The precision of the measurements is within 10% in the concentration range 0-5 µM. Results of the first full-operative week during the second half of September 2004, before the accident

Damages…

Preliminary outcomes 1.Analysis of data collected allowed to verify that most of the sensors were correctly operating:  Automatic daily data transmission from the buoy to the OGS ftp server verified;  Automatic transmission of status messages via verified;  Status parameters (battery voltage, current consumption etc.) inside the expected ranges;  Operation of the CTD chain verified; 2.Some problems occurred:  conductivity sensor of the CTD mounted at 100 m gave false readings;  CT mounted at buoy hull did not responded;  All meteo data, apart of the calculated sustained and gust values, were saved in a wrong format in the hourly message (due to a bug in the data acquisition software, identified and corrected)

Some more.. 3.Operation of the nutrient analyser integrated to the automatic water sampling system verified  measurements at 5 depths every 12 hours  each measurement consists of 3 measurement cycles (macro S) + 1 calibration cycle (Macro T)  a refresh cycle (macro R) every half an hour  reagents stored in a fridge unit to increase autonomy

Some outcomes for the Nas…  A part the first profile, there is a substantial constancy of the nitrate levels with time;  the innovative pumping system and the analytical apparatus demonstrated to work almost perfectly, allowing the automatic collection, for the first time to our knowledge, of nitrate vertical profiles from an open sea buoy;  The recovery of the mooring after the accident gave us the occasion to further improve the system with a partial re-design of the pump-tubes line;  A part the first profile, there is a substantial constancy of the nitrate levels with time;  the innovative pumping system and the analytical apparatus demonstrated to work almost perfectly, allowing the automatic collection, for the first time to our knowledge, of nitrate vertical profiles from an open sea buoy;  The recovering of the mooring after the accident give us the occasion to further improve the system with a partial re-design of the pump-tubes line;

Future developments…  Following the (possible) insurance company payment for the damages and lost components, completion of the original E2M3A configuration will be done;  The buoy will be re-deployed next March 2005, during an oceanographic cruise of the Italian R/V Urania. In this occasion, the SAILOR site (Southern Adriatic Interdisciplinary Laboratory for Oceanographic Research) will be implemented with a sediment trap at 150 m depth.  According with the financial resources, the system will be implemented in the future with a 3-line nutrient analyzer (nitrate, phosphate and silicate), together with an automatic sampler for biological samples.