1 / 13

Yoyo 2001 Ocean ODYSSEY EC MAST III project Contract MAS 3 -CT97-0130

Yoyo 2001 Ocean ODYSSEY EC MAST III project Contract MAS 3 -CT97-0130. LODYC/CNRS Paris/France. http://www.lodyc.jussieu.fr/yoyo/francais/Frenchyoyo.html. TABLE OF CONTENTS. Introduction. History Follow-on. Profiler vehicle. Yoyo 2001. Future:. Banyuls. final test. Mooring line.

breena
Télécharger la présentation

Yoyo 2001 Ocean ODYSSEY EC MAST III project Contract MAS 3 -CT97-0130

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Yoyo 2001Ocean ODYSSEYEC MAST IIIprojectContract MAS 3 -CT97-0130 LODYC/CNRS Paris/France http://www.lodyc.jussieu.fr/yoyo/francais/Frenchyoyo.html

  2. TABLE OF CONTENTS Introduction History Follow-on Profiler vehicle Yoyo 2001 Future: Banyuls final test Mooring line Field tests: Casablanca and Blanes Surface Buoy ANAIS Payload Sensors

  3. INTRODUCTION Within the MAST III-EC funded YOYO 2001-Ocean ODYSSEY project (1998-2001) , an autonomous in situ multidisciplinary ocean observatory was developed which provides a wide range of oceanographical data over the top 1000m of the water column. The main scientific objective is to monitor over the mixed layer and the main thermocline the complex physical and biogeochemical interactions governing the carbon cycle and its associated elements in the ocean. Auotnomous profiling up to the surface opens a wide range of possible scientifis applications ranging from specific process studies to climate monitoring. This project involves some major technological challenges in term of development of novel sensors, data transmission, the profiling vehicle itself and the mooring (a new surface buoy was developed). The system is totally integrated: the YOYO 2001 profiler supplies the energy for all sensors; the central brain of the vehicle commands the sampling acquisition of each sensor, stores the data in memory and sends it at the proper time of transmission. The profiler adapts its rising and descending speed to the sampling strategy and the response time of the various sensors. This eulerian profiling instrument package permits long term in situ monitoring of the ocean and is an important component of the Global Ocean Observing System (GOOS).

  4. FOLLOW-ON OF A SUBSURFACE YOYO The YOYO-2001 project is to follow-on of a subsurface yoyo (Provost and du Chauffaut, 1996-1998) and benefits from the experience and skills gained in the course of development and testing of the latter. The YOYO is moved by a change of flotation due to pumping in and out hydraulic oil from an external bladder to an internal reservoir.This subsurface YOYO moves up and down along a taut cable of a subsurface mooring between a depth of 100 meters and a subsurface depth of about 50 meters. Subsurface YOYO’s q- are deployed at the equator and 20°W within the PIRATA mooring array (in the Atlantic) and at 41°S and 55°30’W within the Brazil Malvinas Confluence (South West Atlantic).

  5. YOYO 2001:A 2 BODY-YOYO For the project YOYO 2001: Ocean Odyssey, LODYC designed a new concept of profiler adapted to carry as many sensors as needed. Conversely to the former, this profiler is a two body yoyo, one body being the vehicle part (similar to the existing subsurface yoyo), and the second body being the sensor carrier part, containing the control card and energy packs for the sensors. An horizontal arm permits minimizing shading effects on the light sensors. The construction of the YOYO and the mechanical interface for the various sensors was made by SME ECA.(Toulon,France) The new electronic for the command card for the various sensors involved in the project Yoyo 2001 is based on a modular system using the bus I²C technology.

  6. THE SURFACE BUOY The surface buoy has to allow the Yoyo profiler to reach the surface. The Yoyo profiler has a one meter long horizontal arm holding the optical sensors. A hole of 5 meter diameter makes it possible for the Yoyo to reach the surface without damage during 90% of the time in the Gulf of Lion. When the weather is too bad, Yoyo told not to reach the surface.(It doesn’t go higher than -20m) The buoy looks like a small offshore 6 legged rig. This shape was chosen because of its stability to pitch and roll. A derrick on top the legs holds the buoy payload and the cable along which the profiler will move up and down. The buoy is made of a steel part and an aluminium part:the steel part was built in Romania (Contantza) and the aluminium part was built in France. It was deployed in the Mediterranean Sea offshore Banyuls in March 2001.

  7. MOORING Until 1998, the YOYO mooring was a subsurface mooring, that is to say it was totally under the surface mooring. It was a subsurface float which was load to maintain the mooring in a vertical position. A surface buoy was load to transmit measures to an Argos satellite thanks to an acoustic link. In order to go to the surface, the mooring has to be modified. It is a two legged mooring with intermediate subsurface flotation. The cable between the surface buoy and intermediate subsurface flotation is elastic. The other part is profiling on a taut cable only attached to the buoy: it is a pendular cable. In case of bad weather, the YOYO is not stuck near the surface. The description of the surface buoy was more particularly developed in an other sheet.

  8. SENSORS Appropriate sampling of physical, biogeochemical, biological and optical processes over a broad range of scales is a key requisite to understand and model the carbon cycle variability in the context of climate range.In particular, repeated sampling of the upper ocean where photosynthetic activity takes place is essential. As a consequence, this project involves some major technological challenges in terms of development of novel sensors. So, the main sensors are presented here: OPC sensor: The initial mechanical integration of the OPC (Optical Plankton Counter) on to the YOYO body took place in Toulon in June 1999. The OPC was attached to the YOYO body using a plastic plaster piece.The aim of this mounting arrangement is to position the OPC intake in a relatively unperturbed flow of water as the YOYO descends. ANAIS sensor: a sheet is specially dedicated to this sensor CTD sensor: this sensor was test this year in Casablanca and the results are available in the sheet “Casablanca oilrig test”. Thanks to numerous tests it works properly and it is ready for the final test. Others sensors: Numerous sensors are present on YOYO body during the field tests.There are light sensors, PCO2, trace metal, fluorimeter and transmissiometer sensors.

  9. THE ANAIS INSTRUMENT The ANAIS instrument developed in the YOYO 2001 project is part of the new instrumentation required for an autonomous in situ monitoring of the Ocean. In order to measure the dissolved macronutrients which are key elements in the oceanic carbon cycle, an Autonomous Nutrient Analyser In Situ (ANAIS) was developed. This chemical analyser is autonomous and it is able to measure simultaneously dissolved nitrates, silicates and phosphates. Since autonomous system capable to measure the macronutrients down to 1000m is presently existing, the Yoyo/ANAIS instrument can be considered as a first step to an in situ multidisciplinary autonomous oceanic observatories. The ANAIS Instrument: The components on the ANAIS analyser are: * 3 chemical analyzers, * an equipressure container, * a system for in situ seawater sampling, * a set of standards and reagents bags, * a 4-electronic cards set for numerical recording and storage of processed data. Silicates Analyser Phosphates Analyser Nitrates Analyser

  10. BLANES TESTS The subsurface profiler equipped with ANAIS and CTD (FSI) was successfully tested from a subsurface mooring deployed off Blanes (Costa Brava, Spain) in october 1999. The YOYO -ANAIS mooring was deployed in autonomous conditions during 2 weeks.Two cycles (profiles) per day were scheduled. Numerous profiles of temperature and salinity were collected between 200m and 1100m. As ANAIS is a slow response sensor, YOYO was rising up slowly at the proper speed 4cm/s in order to obtain the required resolution. Profiles are shown in this figure:

  11. CASABLANCA TESTS-1998 Modifications, made to the vehicle part in order to reach the surface and regulate its velocity as required by the various sensors,have been successfully tested from the Casablanca oil rig, near Tarragona, Spain. The profiler adapts its rising and descending speed to the sampling strategy and the response time of the various sensors. Here the rising speed is about 0.06m/s and the descending speed 0.45m/s. This test with a single body Yoyo in Casablanca also celebrated the adaptation of the new acoustic system.

  12. CASABLANCA OILRIG TEST The 2-body YOYO was tested in order to check: -the accuracy of the velocity regulation during ascent and descent. -the acquisition card developed by LODYC and data storage with all sensors. The YOYO completed 27 cycles of 3 hours over 3 days. The mean ascent and descent speeds were respectively 4.5cm/s and 40cm/s. When the weather is too bad (pictures on the right), YOYO was blocked at 40m under the sea surface. This phenomenom is a good-effect of the “pendulum-like mooring” : the drag component forces the YOYO to go down, this is the way to avoid the YOYO being damaged at the surface.It would not be the same if the YOYO cable was fixed on the bottom. Concerning data acquisition system, it has been worked properly.

  13. LODYC/CNRS Paris France Coordinator:C.PROVOST CNRS-LODYC Tour 14-15 4,Place Jussieu 75252 PARIS CEDEX 5, France cp@lodyc.jussieu.fr PARTNERS LODYC,Paris,France SOC,Southampton,UK LEGOS,Toulouse,France IPG,Karlsruhe,Germany CEAB,Blanes,Spain SME ECA,Toulon,France SI,Southshampton,UK LIM/UPC,Barcelona,Spain

More Related