Bucas, Karenn

Dorval, Philippe

Hamon, Michel

Le Gall, Christian

Le Roux, Dominique

Sarradin, Pierre Marie

Sudreau, Jean-Pierre

Vuillemin, Renaud

UPCommons. Portal del coneixement obert de la UPC

INSTRUMENTATION VIEWPOINTSessions9CHEMINI is built around two modules:The hydraulic module is an equipressurized tank fi lled with dielectric oil ( right handside in Fig.1). Two peristaltic pumps and eight 3-port SMC solenoid valves are used for circulation of the diff erent fl uids: reagents, standards and samples. Three solenoid valves constitute the injection system whereas 5 ones build a 6 ways selection system. Most of the manifold tubing is replaced by an engraved circuit in PMMA. The pumps and valves are integrated directly on the manifold limiting the use of tubing and connecting parts. The detection mod-ule (left handside in Fig.1) holds the electronic cards and the colorim-eter in a pressure tank in Titanium. The quartz fl ow cell, manufactured by HELLMA, is placed outside this tank. The light is emitted by LEDs to the external quartz fl ow cell and returns to the colorimeter board via optic fi bres and special waterproof titanium optic pass through (SEDI). Much of the development eff ort on this in situ analyser has focused on miniaturisation. Its low weight (12,6 kg without reagents) and small dimensions (130mm H x 148mm L x 120mm l for the hy-draulic module and 264mm H x 140mm D for the detection module) permits simple and accommodating operations for on site deploy-ment, speaking of implementation on submersible, long-term ben-thic station and at sea maintenance. 2.2 Chemical specifi cations and performancesThe chemical parameters to be measured are total sulphide (ΣS) and total iron (FeII + FeIII). The analytical methods based on colorimet-ric detection have been extensively studied at Ifremer [1, 3, 4]. Other parameters are envisaged and the analysers will be versatile for ex-isting chemical analysis methods (nitrite, nitrate, phosphate, silicate, pH, pCO2…) and opened for new developments. CHEMINI is the new generation of chemical analyser and is able to work with the various principles of fl ow analysis (FIA, CFA, stop fl ow, …).2.3 At sea trialsDuring the MOMARETO cruise[5] (Azores, MoMAR zone, august 2006), trials were performed in two steps corresponding to the two legs of the cruise. The fi rst leg was partly focussed on the technical valida-tion of CHEMINI. The second leg was devoted to the operational use of CHEMINI to characterize the spatial distribution of mussel’s assem-blages on the Eiff el Tower hydrothermal edifi ce. CHEMINI was used on a remote controlled mode implemented on the ROV VICTOR. The sample lines of the two CHEMINI were directly connected to the ROV sample inlet with 2 ways available for each CHEMINI in case of plug-ging. The two CHEMINI have been involved in twelve dives, doing 631 samples measurements for total iron and 524 samples measure-ments for total sulphide with periodic in situ calibration. During the last days of the cruise, CHEMINI Iron has been implemented on the TEMPO autonomous seabed station coupled to the AIM video cam-era and an autonomous temperature sensor. The whole system has been deployed on the Lucky Strike site for one year. The sample inlet was positioned by Victor in a mussel bed. The measurement rate was set at 8 measurements per day. The recovery is planned in July 2007.3. ConclusionTwo prototypes of CHEMINI deep-sea are available and operational to perform total sulphide and total iron measurements in hydrother-mal environments. We have succeeded in decreasing the dimensions of the analyser with a real miniaturised system easy to implement in diff erent vectors such as the ROV Victor or the TEMPO monitoring station. CHEMINI integrates some innovative parts like the engraved manifold and the detection module. This module allows obtaining in situ analytical performances similar to laboratory products. Last, the system has proved a very good reliability during the fi nal demonstra-tion cruise with a number of dives and data obtained never reached before. The two analysers have been validated during the fi rst leg of M1CHEMINI: CHEMICAL MINIATURISED ANALYSERR. Vuillemin, D. Le Roux, P. Dorval, K. Bucas, M. Hamon, J.P. Sudreau, C. Le Gall, P.M. SarradinIfremer, Départements TSI et DEEP de Brest, 29 280 Plouzané, FranceTel : 33 2 98 22 48 90, e-mail Renaud.Vullemin@ifremer.fr1. IntroductionThe development of in situ analysers to make chemical measure-ments in marine environment seems nowadays essential to allow the chemical characterisation of habitats prevailing in hydrothermal vent ecosystems. In situ chemical analysis off ers numerous advantages such as the limitation of the modifi cation of the sample with an im-mediate analysis, the possibility to perform high frequency automat-ed measurement giving an access to steep chemical gradients, the potential to do real-time survey and in situ calibration. In situ chemi-cal analysis is made possible by the use of fl ow analysis. Several types of fi eld analysers have already been developed in Ifremer during the 90’s. It is the case of the deep sea version « Alchimist » [1] (certifi ed for depths down to 6000 m), used for the determination of iron and sulphur in hydrothermal zones and also for the determination of sub-nanomolar concentrations of iron in coastal waters[2].“CHEMINI” constitutes the new generation of analysers developed by Ifremer within the department Technology of the Instrumental Systems for the measurement of sea water chemical parameters. The choice of elements composing this new generation was made according to several rules: reliability, analytical performances, mini-aturization to easily implement CHEMINI on deep submersibles, con-sumption (energy and reagent), and costs.2. Results and discussionCHEMINI (cf. Fig.1) is a mono parameter in situ chemical analyser and is assimilated to a sensing element. Several advantages are arising from this concept, the ability to make simultaneous measurements, the independence of each measurement, a reliability increase, the possible use of diff erent detection methods, the modularity of the system (1, 2, 3 or more parameters). The analysers can be set seri-ally on a sampling line and controlled by a single software. CHEMINI can be integrated on diff erent vectors (ROV, AUV, seabed station…) and be used in a teleoperated mode or in an autonomous way. The deep-sea version of CHEMINI allowing the in situ determination of iron[3] and sulphide[4] was developed during the EXOCET/D Euro-pean project.Figure 1 CHEMINI deep sea version 2.1 ConceptINSTRUMENTATION VIEWPOINTSessions10optic pass through (SEDI). Much of the development eff ort on this in situ analyser has focused on miniaturisation. Its low weight (12,6 kg without reagents) and small dimensions (130mm H x 148mm L x 120mm l for the hydraulic module and 264mm H x 140mm D for the detection module) permits simple and accommodating operations for on site deployment, speaking of implementation on submers-ible, long-term benthic station and at sea maintenance. 2.2 Chemical specifi cations and performancesThe chemical parameters to be measured are total sulphide (ΣS) and total iron (FeII + FeIII). The analytical methods based on colorimet-ric detection have been extensively studied at Ifremer [1, 3, 4]. Other parameters are envisaged and the analysers will be versatile for ex-isting chemical analysis methods (nitrite, nitrate, phosphate, silicate, pH, pCO2…) and opened for new developments. CHEMINI is the new generation of chemical analyser and is able to work with the various principles of fl ow analysis (FIA, CFA, stop fl ow, …).2.3 At sea trials.During the MOMARETO cruise[5] (Azores, MoMAR zone, august 2006), trials were performed in two steps corresponding to the two legs of the cruise. The fi rst leg was partly focussed on the technical valida-tion of CHEMINI. The second leg was devoted to the operational use of CHEMINI to characterize the spatial distribution of mussel’s assem-blages on the Eiff el Tower hydrothermal edifi ce. CHEMINI was used on a remote controlled mode implemented on the ROV VICTOR. The sample lines of the two CHEMINI were directly connected to the ROV sample inlet with 2 ways available for each CHEMINI in case of plug-ging. The two CHEMINI have been involved in twelve dives, doing 631 samples measurements for total iron and 524 samples measure-ments for total sulphide with periodic in situ calibration. During the last days of the cruise, CHEMINI Iron has been implemented on the TEMPO autonomous seabed station coupled to the AIM video cam-era and an autonomous temperature sensor. The whole system has been deployed on the Lucky Strike site for one year. The sample inlet was positioned by Victor in a mussel bed. The measurement rate was set at 8 measurements per day. The recovery is planned in July 2007.3. ConclusionTwo prototypes of CHEMINI deep-sea are available and operational to perform total sulphide and total iron measurements in hydrother-mal environments. We have succeeded in decreasing the dimensions of the analyser with a real miniaturised system easy to implement in diff erent vectors such as the ROV Victor or the TEMPO monitoring station. CHEMINI integrates some innovative parts like the engraved manifold and the detection module. This module allows obtaining in situ analytical performances similar to laboratory products. Last, the system has proved a very good reliability during the fi nal demonstra-tion cruise with a number of dives and data obtained never reached before. The two analysers have been validated during the fi rst leg of the MoMARETO cruise and used operationally during the scientifi c part. Finally, CHEMINI Iron was implemented on the TEMPO seabed station and leaved on the Lucky Strike site to perform Fe monitor-ing for one year. It will be recovered on July 2007, and will allow us to evaluate the analyser through a long term deployment which has never been done before especially for a so long duration. We plan in the future to adapt new chemistries on CHEMINI, and to use CHEMINI technology to use passive sensors on a fl ow system.4. AcknowledgementsFunding for the development of CHEMINI was obtained from the European Union EXOCET/D program (2004-2006, FP6-GOCE-CT-2003-505342). 5. References[1] Le Bris, N., Sarradin, P.M., Birot, D., Alayse-Danet, A.M., Marine Chemistry, 72, 1-15, 2000.[2] Laës, A., Vuillemin, R., Leilde, B., Sarthou, G., Bournot – Marec, C., Blain, S., Marine Chemistry, 97, 347-356, 2005.[3] Sarradin, P-M., Le Bris, N., Le Gall, C., Rodier, P, Talanta, Volume 66, Issue 5, 1131-1138, 2005.[4] Sarradin, P-M., Le Bris, N., Birot D., Caprais J.C., Analytical Communication, 36, 157-160, 1999. [5] Sarrazin J., P.M. Sarradin and the MoMARETO cruise participants. InterRidge News, 24-33, 2006.SMOS: MEASURING SEA SURFACE SALINITY FROM SPACEC. Gabarró, J. Font and M. TaloneInstitut de Ciències del Mar, CMIMA-CSIC, Barcelona.Pg. Marítim  de la Barceloneta 37-49, Barcelona 08003.Telephone: +34932309602, email: cgabarro@icm.csic.es1. IntroductionThe distribution and variability of salinity in the world’s oceans is a key parameter to understand the role of the oceans in the climate system. However, until now, remote sensing of the sea surface salinity (SSS) from space has not been attempted. SMOS (Soil Moisture and Ocean Salinity) [1], due to be launch by end 2008, is a European Space Agency mission that aims at generating global ocean salinity maps with an accuracy of 0.1 psu, at spatial and temporal resolution suitable for climatic studies. The satellite sensor is an L-band (1400–1427 MHz) aperture synthesis interferometric radiometer [2]. Sea surface salinity (SSS) can be retrieved since the brightness temperature of sea water is dependent on the frequency, angle of observation, dielectric constant of sea water, sea surface temperature and sea surface state.The SSS maps are expected to have an accuracy of 0.1 psu at a spatial resolution of 100–200 Km every 10–30 days. The individual measure-ment is expected to have an accuracy of 1psu with a resolution of 15 Km. Salinity modifi es the dielectric constant of sea water and it is one of the parameters that determine the sea surface emissivity [3]. At L-band, a restricted band for passive observations, the brightness tem-perature (Tb, measure of the sea surface emission) presents a maxi-mum sensitivity to SSS. However, the sensitivity is quite low: 0.5 K/psu at sea surface temperature (SST)=20 ºC, and decreases to 0.25 K/psu at SST=0 ºC [4]. Moreover, Tb at this frequency is also sensible to sea surface roughness, 0–0.4 K/(m/s), (when roughness is parameterised in terms of wind speed) depending on the incidence angle [5], and to SST, 0.2–0.4 K/ºC. This situation indicates that it is necessary to have an accurate knowledge of the surface roughness and SST (auxiliary parameters) to retrieve salinity with enough accuracy.To increase the present understanding of the sensitivity of Tb to wind speed and direction at L-band, the European Space Agency (ESA) sponsored the WInd and Salinity Experiments (WISE). These experi-ments aimed, among other activities, at improving and validating the actual sea surface emissivity models at L-band [6].2. Campaigns and ongoing studiesWISE 2000 and 2001 took place at the Casablanca oil rig platform in the Mediterranean Catalan coast, at 40º 43.02’ N 1º 21.50’ E, 40 Km off -shore [7]. They were performed during one month in autumn, when maximum wind speed is expected in the region. An L-band full-polar-imetric radiometer measured Tb from 33 m above sea level at diff er-M1

CHEMINI: chemical miniaturised analyser

CHEMINI: chemical miniaturised analyser

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